Manual Therapy Journal - Volume 9, Issue 3, Pages 123-182 (August 2004)

VOLUME 9 NUMBER 3 PAGES 123– 182 AUGUST 2004 Editors International Advisory Board Ann Moore PhD, GradDipPhys, FCSP, C...

Author: Editors: Ann Moore and Gwen Jull

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VOLUME 9 NUMBER 3 PAGES 123– 182 AUGUST 2004

Editors

International Advisory Board

Ann Moore PhD, GradDipPhys, FCSP, CertEd, MMACP Clinical Research Centre for Healthcare Professions University of Brighton Aldro Building, 49 Darley Road Eastbourne BN20 7UR, UK

K. Bennell (Victoria, Australia) B. Carstensen (Frederiksberg, Denmark) E. Cruz (Setubal Portugal) L. Danneels (Mar|¤ akerke, Belgium) S. Durrell (London, UK) S. Edmondston (Perth, Australia) J. Endresen (Flaktvei, Norway) L. Exelby (Biggleswade, UK) J. Greening (London, UK) C. J. Groen (Utrecht,The Netherlands) A. Gross (Hamilton, Canada) T. Hall (West Leederville, Australia) W. Hing (Auckland, New Zealand) M. Jones (Adelaide, Australia) S. King (Glamorgan, UK) B.W. Koes (Amsterdam,The Netherlands) D. Lawrence (Lombard, IL, USA) D. Lee (Delta, Canada) L. Ma¡ey-Ward (Calgary, Canada) J. McConnell (Northbridge, Australia) S. Mercer (Dunedin, New Zealand) E. Maheu (Quebec, Canada) D. Newham (London, UK) L. Ombregt (Kanegem-Tielt, Belgium) N. Osbourne (Bournemouth, UK) M. Paatelma (Jyvaskyla, Finland) N. Petty (Eastbourne, UK) A. Pool-Goudzwaard (The Netherlands) M. Pope (Aberdeen, UK) G. Rankin (London, UK) M. Rocabado (Santiago, Chile) C. Shacklady (Manchester, UK) D. Shirley (Lidcombe, Australia) V. Smedmark (Stenhamra, Sweden) W. Smeets (Tongeren, Belgium) C. Snijders (Rotterdam,The Netherlands) M. Sterling (St Lucia, Australia) R. Soames (Leeds, UK) P. Spencer (Barnstaple, UK) P. Tehan (Victoria, Australia) M. Testa (Alassio, Italy) M. Uys (Tygerberg, South Africa) P. van Roy (Brussels, Belgium) B.Vicenzino (St Lucia, Australia) H.J.M.Von Piekartz (Wierden,The Netherlands) M.Wallin (Spanga, Sweden) A.Wright (Winnipeg, Canada) M. Zusman (Mount Lawley, Australia)

Gwendolen Jull PhD, MPhty, Grad Dip ManTher, FACP Department of Physiotherapy University of Queensland Brisbane QLD 4072, Australia Editorial Committee Karen Beeton MPhty, BSc(Hons), MCSP MACP ex o⁄cio member Department of Allied Health Professions—Physiotherapy University of Hertfordshire College Lane Hat¢eld AL10 9AB, UK Je¡rey D. Boyling MSc, BPhty, GradDipAdvManTher, MAPA, MCSP, MErgS Je¡rey Boyling Associates Broadway Chambers Hammersmith Broadway London W6 7AF, UK Darren A. Rivett PhD, MAppSc (ManiPhty) GradDip ManipTher, BAppSc (Phty) Discipline of Physiotherapy Faculty of Health The University of Newcastle Callaghan, NSW 2308, Australia Kevin P. Singer PhD Centre for Musculoskeletal Studies Department of Surgery The University of Western Australia, Royal Perth Hospital Level 2, MRF Building, 50 rear, Murray Street Perth,WA 6000, Australia Raymond Swinkels MSc, PT, MT (Book Review editor and NVMTex o⁄cio member) Ulenpas 80 5655 JD Eindoven The Netherlands

Visit the journal website at http://www.elsevierhealth.com/journals/math doi: 10.1016/S1356-689X(04)00045-1

ARTICLE IN PRESS

Manual Therapy 9 (2004) 123–124

www.elsevier.com/locate/math

Editorial Our great collective ignorance about the effect of health care was most clearly stated by a British epidemiologist, Archie Cochrane in the early seventies (Archie Cochrane, 1972). We could reasonably ask, ‘‘how much has changed in the last three decades?’’ Clinicians continue to be overwhelmed with healthcare information. One method to summarize the volumes of information is with the use of systematic review techniques. Internationally, the Cochrane Collaboration has taken the lead to develop clear standards for preparing, maintaining and promoting the accessibility of systematic review. What then, is a systematic review and how should it be used? A systematic review is a research design that uses clearly defined methods, which have been detailed in numerous Cochrane and nonCochrane publications (de Bie, 1996), as follows: * * *

*

*

*

Objectives and eligibility criteria are stated. Systematic searches for studies are conducted. Tabulation of study characteristics and methodological assessment of quality is performed. Exclusions are justified. Analysis of eligible studies using quantitative or statistical synthesis is made if possible and appropriate. Sensitivity or subgroup analysis is performed if appropriate. Conclusions are drawn and recommendations are made. This should describe who should act and what should be different.

Importantly, systematic reviews are different from a meta-analysis. Meta-analysis is a statistical analysis or integration of several separate or independent study results. The reviewer or analyst must consider the data from these separate studies to be combinable. Metaanalysis may or may not be a component of a methodologically sound systematic review. A wellconducted meta-analysis allows for a more objective appraisal of the evidence, may lead to the introduction of effective treatments more quickly, and may resolve existing uncertainty and disagreement. There is a risk that meta-analyses produce very precise but equally spurious results. More importantly perhaps, is the fact that differences between studies, heterogeneity, may point to important features that are critical in producing the desired results. The possible sources of heterogeneity should be examined. 1356-689X/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2004.02.001

Confounding exists when a factor is related to both the exposure and the outcome. Randomized trials are less prone to confounding than other designs, but when non-randomized trials are summarized in a systematic review, confounding in the original trials should always be sought. Bias in the conduct of the systematic review or in the original studies may distort findings. Biases to guard against in systematic reviews include selection bias, publication bias, and language bias, all of which can also distort the findings and conclusions. Selection bias occurs when interest sources or knowledge of results of a set of potential studies influence the selection and inclusion of studies. Studies with significant results are more likely to get published than those with nonsignificant findings—publication bias. Studies with significant results are more likely to get published in English—language bias. The presence or absence of such bias should be examined during sensitivity analysis. We must use reliable unbiased evidence about the effects of specific elements of health care that has been prepared systematically so we can identify the important effects of health care (good and bad) and we can service those with ill health adequately. Systematic reviews and meta-analyses of smaller trials have less impact and perhaps a smaller degree of influence on clinical practice than large randomized trials showing beneficial effects of treatment. Unfortunately, we have few large trials in the musculoskeletal field in general. Systematic reviews help us as decision makers in keeping up-to-date and ensure relevance of clinical practice, plan for new research by avoiding asking questions that have already been answered, and make decisions in our heath service communities. Results very rarely have universally relevant implications. Local disease burdens and barriers to implementation vary widely from country to country and place to place within a country. Local attention to these issues will ensure the transfer of knowledge. As musculoskeletal therapists, we are decision makers. Good decisions about health care rely on more than good reviews of the results of research. Decisions about the care of our individual patient are made in the context of our clinical expertise as well as our patient’s expertise and preferences (knowledge of their condition, the treatment offered). Thoughtful and compassionate application of treatment to our patients is part of this caring process. Effective mechanisms are needed for implementing evidence-based decisions efficiently. We should consider

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Editorial / Manual Therapy 9 (2004) 123–124

the following questions when transferring knowledge from systematic reviews into our practice: * *

*

*

*

*

*

Why is the review result important? What does the evidence show and is it from a rigorous source? How does current practice differ from what the evidence says? What does this research mean for you as the decision maker? Should you implement change and if so, what should be different? What are the barriers to knowledge uptake for you and your practice environment? The most common challenges we are faced with are time, availability of research results, resources to implement research findings, relevance, or timeliness—having research when needed. How can you become actively involved in addressing these issues and actively transferring the knowledge to your practice?

We as active decision makers must consider people’s needs, the availability of resources, and priorities. It is only when the evidence based knowledge has been transferred into our practices that our great collective ignorance about the effect of health care has a chance of changing.

References Cochrane AL. Effectiveness and efficiency. Random reflections on health services. London: Nuffield Provincial Hospital Trust; 1972. de Bie RA. Methodology of systematic reviews: an introduction. Physical Therapy Review 1996;1:47–51.

A. Gross 80 Traymore Ave, Hamilton, Ont., Canada E-mail address: [email protected]

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Masterclass

Unravelling the complexity of muscle impairment in chronic neck pain D. Falla* Division of Physiotherapy, The University of Queensland, Brisbane QLD 4072, Australia Received 4 May 2004; accepted 8 May 2004

Abstract Exercise interventions are deemed essential for the effective management of patients with neck pain. However, there has been a lack of consensus on optimal exercise prescription, which has resulted from a paucity of studies to quantify the precise nature of muscle impairment, in people with neck pain. This masterclass will present recent research from our laboratory, which has utilized surface electromyography to investigate cervical flexor muscle impairment in patients with chronic neck pain. This research has identified deficits in the motor control of the deep and superficial cervical flexor muscles in people with chronic neck pain, characterized by a delay in onset of neck muscle contraction associated with movement of the upper limb. In addition, people with neck pain demonstrate an altered pattern of muscle activation, which is characterized by reduced deep cervical flexor muscle activity during a low load cognitive task and increased activity of the superficial cervical flexor muscles during both cognitive tasks and functional activities. The results have demonstrated the complex, multifaceted nature of cervical muscle impairment, which exists in people with a history of neck pain. In turn, this has considerable implications for the rehabilitation of muscle function in people with neck pain disorders. r 2004 Elsevier Ltd. All rights reserved.

1. Introduction Chronic neck pain is becoming increasingly prevalent in society. Estimations indicate that 67% of individuals will suffer neck pain at some stage throughout life (Cote et al., 1998). With an increasing sedentary population, especially with reliance on computer technology in the workplace, it is predicted that the prevalence rate will continue to rise. Effective management of this condition is vital, not only for the relief of symptoms but perhaps more importantly, for the prevention of recurrent episodes of cervical pain, personal suffering and lost work productivity. It is estimated that the osseoligamentous system contributes 20% to the mechanical stability of the cervical spine while 80% is provided by the surrounding neck musculature (Panjabi et al., 1998). The ligaments’ role in stabilization occurs mainly at end of range postures (Harms-Ringdahl et al., 1986) while muscles *Corresponding author. Tel.: +61-7-3365-4529; fax: +61-7-33652775. E-mail address: [email protected] (D. Falla). 1356-689X/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2004.05.003

supply dynamic support in activities around the neutral and mid-range postures, which are commonly adopted during functional daily tasks. In the presence of injury or pathology, the role of the muscular system becomes even greater which highlights the need to address the muscle system during both the assessment and rehabilitation of patients with neck pain. Exercise interventions are deemed essential for the effective management of patients with neck pain. In the past however, there has been a lack of consensus on optimal exercise prescription. This results from a paucity of studies to quantify the precise nature of impairment in both the deep and superficial cervical muscles in neck pain patients. Anecdotal evidence (Janda, 1994) suggests the cervical flexor muscles become dysfunctional in the presence of neck pain. Furthermore, simple clinical mechanical measures have demonstrated a reduction in the strength and endurance capabilities of the cervical flexor muscles in neck pain patients (Silverman et al., 1991; Vernon et al., 1992; Watson and Trott, 1993; Barton and Hayes, 1996; Placzek et al., 1999). However, such basic mechanical measures may oversimplify the deficits

ARTICLE IN PRESS D. Falla / Manual Therapy 9 (2004) 125–133

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present this recent evidence from our laboratory of the complexity of cervical muscle impairment in neck pain patients and in turn will highlight the implications for rehabilitation.

within the muscle system in people with neck pain disorders. Detection, recording and analysis of myoelectric signals with surface electromyography (EMG) provides a more sophisticated means of determining aberrant muscle function. Although EMG has been used to analyse superficial cervical muscle function in the past, such investigations are infrequent and regular inconsistencies in the applied methodology limits the interpretation of results. Moreover, the inaccessibility of the deep cervical flexor (DCF) muscles has rendered the use of conventional surface EMG measures inappropriate. Recent research has refined the application of surface EMG for the assessment of the cervical flexor muscles. This has involved optimizing the application of surface EMG for the assessment of the superficial cervical flexors (sternocleidomastoid and the scalenes) (Falla et al., 2002a, b) and secondly establishing a new EMG electrode and technique for obtaining a direct measure of the DCF muscles (Falla et al., 2003a). Upon developing the methodology we investigated cervical flexor muscle function in patients with neck pain in three main areas of EMG assessment (1) myoelectric manifestations of cervical muscle fatigue (2) analysis of the cervical flexor muscle activation patterns and (3) analysis of cervical neuromotor control. This paper will

2. Muscle fatigability Numerous studies have demonstrated a reduction in the strength and endurance capacity of the cervical flexor and extensor muscles in patients with neck pain (Watson and Trott, 1993; Treleaven et al., 1994; Barton and Hayes, 1996; Placzek et al., 1999). With advances in EMG technology, more sophisticated measures have been used to quantify cervical muscle fatigability in patients with neck pain (Falla et al., 2003b, 2004e, f; Gogia and Sabbahi, 1994). In a recent study (Falla et al., 2003b) we examined fatigability of the sternocleidomastoid (SCM) and anterior scalene (AS) muscles during sustained cervical flexion contractions at 25% and 50% of the maximum voluntary contraction (MVC) in patients with chronic neck pain compared to controls. Greater myoelectric manifestations of SCM and AS muscle fatigue were identified for the neck pain patient group as indicated by a significantly greater slope of the mean frequency (Fig. 1). Whilst the results of our study

Visual feedback display Direction of neck effort

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Fig. 1. (A) The subject’s head rests on a padded head support of a custom designed cervical flexion force-measuring device. An adjustable Velcro strap is fastened across the forehead acting to stabilize the head and provide resistance during cervical flexion isometric contractions. (B) Example of fatigue plots obtained from the SCM muscle of a neck pain patient and control subject contracting at 50% of the MVC for the EMG variables average rectified value (ARV), conduction velocity (CV), and mean frequency (MNF). The values of each variable are normalized with respect to the intercept of the regression line. Greater fatigue of the SCM muscle is evident for the neck pain patient as characterized by the faster rate of change of the MNF over time. (Adapted from Fig. 2 in Falla et al., 2003b).


confirmed greater fatigability of the cervical flexors at moderate loads (50% MVC) which was identified by Gogia and Sabbahi (1994), our results also established greater cervical flexor muscle fatigability during low load sustained contractions (25% MVC) in the patient group which reflects the clinical observation of reduced endurance in the cervical flexors in neck pain patients (Treleaven et al., 1994; Watson and Trott, 1993; Barton and Hayes, 1996; Placzek et al., 1999). Furthermore, an increase of the mean frequency at the beginning of the contraction was observed for both muscles in the neck pain group. This could be attributed to modification of the recruited motor unit pool in which the number of type II fibres is increased with respect to the type I fibres. These findings were in accordance with results of muscle biopsy studies of subjects with neck pain undergoing spinal surgery, which established an increase in the number of type-IIC transitional fibres in the neck flexor muscles resulting from transformations of slow-twitch oxidative type-I fibres to fast-twitch glycolytic type-IIB fibres (Uhlig et al., 1995). Subsequent to these results, the specificity of this aberrant muscle function was analysed (Falla et al., 2004e). In examining for differences in the fatigability of SCM and AS muscles between the painful and nonpainful sides in patients with chronic unilateral neck pain, results revealed greater estimates of the initial value and slope of the mean frequency for both the SCM and AS muscles ipsilateral to the side of pain at 25% and 50% of MVC. These results indicate the need to address fatigability of the cervical flexor muscles when prescribing therapeutic exercise for neck pain patients. The outcomes advocate the need for specificity and perhaps a unilateral bias to therapeutic exercise in the management of patients with unilateral neck pain to attain optimal muscle rehabilitation. Of interest, the duration of neck pain does not appear to correlate with the extent of SCM and AS muscle fatigability in patients with chronic neck pain. This finding would suggest that the greater fatigability of the cervical flexor muscles, which has been identified in patients with neck pain, occurs early with the onset of neck pain and does not worsen with time (Falla et al., 2004f).

3. Muscle activation patterns during cognitive tasks Whilst direct evidence of deep cervical extensor muscle dysfunction has been identified in neck pain patients (Hallgren et al., 1994; McPartland et al., 1997), until recently, there was no succinct evidence that described impairment in the DCF muscles. The DCF muscles, including the longus colli, longus capitis, rectus capitis anterior and rectus capitis lateralis, are histologically and morphologically designed to provide support to the cervical lordosis and the cervical joints (Winters

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and Peles, 1990; Mayoux-Benhamou et al., 1994; Conley et al., 1995; Vasavada et al., 1998; Boyd Clark et al., 2001, 2002). Accordingly, our research has been orientated towards the identification and quantification of deficits in the DCF muscles in patients with neck pain disorders. Our interest commenced with the development of the cranio-cervical flexion (C-CF) test (Jull et al., 1999; Jull, 2000), which is a low load task, based on the anatomical action of the deep longus capitis and colli muscles. The C-CF test was considered to provide an indirect measure of DCF muscle activation and endurance capacity, which could be utilized in a clinical environment. The test is performed in crook lying, and requires the person to perform a head nod action (cranio-cervical flexion) in five incremental stages of increasing range and hold each position for 5–10 s. Performance is guided by feedback from a pressure sensor, which is positioned suboccipitally to monitor the flattening of the cervical lordosis, which occurs with the contraction of longus colli (Mayoux-Benhamou et al., 1994, 1997). Earlier clinical research demonstrated significantly inferior performance on the C-CF test in patients with idiopathic neck pain and with neck pain after a whiplash injury (Jull et al., 1999; Jull, 2000). In general, patients demonstrated a reduced ability to reach and maintain the targets of pressure in the cuff under the cervical spine. Furthermore, surface EMG recordings of the superficial cervical flexor (sternocleidomastoid) indicated that performance on the test was associated with significantly higher EMG amplitude of this muscle compared with controls (Jull, 2000; Jull et al., 2004b). Based on this research it was hypothesized that impaired performance on the C-CF test (1) reflected a deficit in motor control of C-CF in patients with neck pain (2) reflected poor activation of DCF muscles and (3) reflected poor muscle support of cervical joints (Jull, 2000). The difficulty in substantiating these hypotheses was related to the difficulty in obtaining a direct recording of the DCF muscles due to their depth and close proximity to nearby structures such as the lymphatic system, the sympathetic chain, vagus nerve and the carotid artery. However, our recent research (Falla et al., 2003a) led to the development of an electrode capable of recording DCF muscle activity (Fig. 2) without the need for fine wire EMG and thus provided the opportunity to corroborate or refute these hypotheses. Utilizing this new EMG technique, we investigated activation of the DCF muscles in patients with and without chronic neck pain during performance of the CCF test (Falla et al., 2004c). The results demonstrated reduced activation of the DCF muscles for the neck pain patient group across all stages of the C-CF test with the difference becoming statistically significant at the higher levels of the test (representing increasingly inner range


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positions of C-CF (Fig. 3). Furthermore, the neck pain patient group demonstrated reduced C-CF range of motion across all stages of the C-CF test (Fig. 3). This finding suggests that the pressure increase in the cuff

under the cervical spine of neck pain patients was induced by a different movement strategy such as head/ neck retraction, which is commonly observed clinically. Based on the results of this study it was concluded that neck pain patients have a disturbance in the neck flexor synergy, where impairment in the deep muscles, important for segmental control and support, appears to be compensated for by increased activity in the superficial muscles (SCM and AS).

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Increased EMG activity of the superficial cervical musculature which has been identified in people with neck pain during performance of the C-CF test (Jull, 2000; Jull et al., 2004b), could be considered an inefficient neuromuscular activation pattern. This concept was explored recently by investigating the neuromuscular efficiency (NME) of the SCM and AS muscles, defined as the quotient of force and the integrated EMG (van der Hoeven et al., 1993), during cervical flexion contractions at 25% and 50% of MVC in patients with and without chronic neck pain (Falla et al., 2004b). The results of our study confirmed less NME for the SCM and AS muscles contracting at 25% MVC in the neck pain patient group. Reduced NME indicates that the neck pain patients required

Nasal septum Nasopharyngeal Electrode

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(B) Fig. 2. (A) Electrode for the detection of DCF muscle activity. (B) A nasopharyngeal application is used to suction surface electrodes over the posterior oropharyngeal wall. The DCF muscles lie directly posterior to the oropharyngeal wall, allowing myoelectric signals to be detected from these muscles (adapted from Figs. 1 and 2 in Falla et al., 2003a).

Visual feedback display Cranio-cervical flexion

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Fig. 3. (A) Subjects were positioned supine with the Pressure Biofeedback Unit placed sub-occipitally behind the neck to detect increases in pressure with the gentle nodding action of C-CF. Subjects received visual feedback of pressure level. (B) Normalized root mean square (RMS) values (mean and standard deviation) for the DCF muscles and percentage of full C-CF range of motion (ROM) for each stage of the C-CF test (C-CFT). Indicates significant difference between control subjects and neck pain patients (Po0:05) (adapted from Figs. 1 and 2 in Falla et al., 2004c).


greater muscular electrical activity to produce an equivalent amount of force as compared to the control subjects, or conversely, with a comparable amount of electrical activity, neck pain patients would produce a lower force output (Falla et al., 2004b). The greater SCM and AS EMG activity recorded for the neck pain group could theoretically be attributed to (1) greater excitability of the motoneuronal pool, (2) modification of neural activation patterns accommodating for weakness or inhibition of another muscle, or (3) a combination of these mechanisms.

5. Muscle activation during functional tasks Until now, the evidence of cervical muscle impairment presented within this manuscript corresponds to altered muscle function identified during prescribed motor tasks. In particular, research has demonstrated the presence of overactivity or neuromuscular inefficiency of the superficial cervical muscles under conditions of low biomechanical load (Jull, 2000; Falla et al., 2004b, c). However, this altered pattern of neuromuscular activation has been detected during non-functional tasks. Therefore, extrapolation of these findings to function must be done so with caution.

In order to assess whether the presence of increased EMG activity of the superficial cervical flexor muscles was present during functional activities in people with neck pain, we investigated activity of the SCM and AS muscles during a low load, functional upper limb task (Falla et al., 2004a). Subjects were asked to perform a repetitive unilateral task, which involved marking three targets, positioned on a desk in front of them, using their right hand. Their left forearm rested motionless on the desk in front of them. Previous research using this task has demonstrated higher co-activation of the upper trapezius muscle in neck pain patients compared to controls during performance of the task and a decreased ability to relax the upper trapezius muscle on completion of the task (Nederhand et al., 2000). As demonstrated in Fig. 4, the altered pattern of muscle activation identified for both idiopathic neck pain and whiplash patients was characterized by increased EMG amplitude for the AS and SCM muscles bilaterally throughout performance of the functional activity. Furthermore, neck pain patients demonstrated a decreased ability to relax the SCM and AS muscles on completion of the task. It was suggested that the altered pattern of muscle activation identified for the neck pain groups represents an altered motor strategy to minimize activation of painful muscles or compensate

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Fig. 5. (A) Group data for neck flexor muscle EMG onsets during unilateral arm movements. Data are shown for the control (white bars) and neck pain subjects (black bars). Mean and standard error of the relative latencies (ms) for the left (L) and right (R) SCM, AS and DCF muscles during unilateral upper limb flexion and extension. Indicates significant difference Po0:05: (B) Representative electromyographic activity with rapid arm movements. Raw EMG data are shown for the anterior deltoid (AD), DCF, SCM and the AS muscles for a control and chronic neck pain subject during rapid upper limb flexion. Note the delayed activation of the neck muscles for the neck pain patient. (Adapted from Figs. 1 and 2 in Falla et al., 2004d).

for inhibited muscles and might represent a functional correlate of performance on the C-CF test (Falla et al., 2004a).

6. Muscle activation during postural perturbations Evidence was starting to reveal specific deficits within the cervical flexor muscles in patients with neck pain. This was identified during performance of prescribed motor tasks and during functional activities. The next stage of our research was to identify whether the automatic function of the cervical muscles was impaired in people with neck pain. We know from research in healthy individuals that during performance of rapid arm movements which induce a postural perturbation, the cervical muscles are co-activated within 50 ms of the onset of deltoid activity. This indicates that this response is too fast to be mediated by even the fastest reflexes. Instead these responses are considered to be preplanned by the nervous system and are termed ‘‘feed-forward’’ adjustments (Gurfinkel et al., 1988; van der Fits et al., 1998; Falla et al., 2004g). In reference to the lumbar spine model, a significant delay has been identified for the transversus abdominis muscle in patients with low back pain during rapid arm movements (Hodges and Richardson, 1996). Utilizing the same experimental model we aimed to determine whether a deficit in the timing of the cervical muscles would be present in people with chronic neck pain. The results of our study confirmed the hypothesis of delayed onset of the DCF and the SCM and AS muscles in

people with a history of neck pain compared to control subjects (Fig. 5) (Falla et al., 2004d). Although each of the neck muscles demonstrated some difference in onset time between groups, the DCF demonstrated the most significant deviation during rapid shoulder flexion. The relative latency of the DCF contraction exceeded the criteria for feed-forward contraction during movements in both directions in the neck pain group, which indicates a significant deficit in the automatic feed-forward control of the cervical spine. Considering the deep cervical muscles, longus colli and longus capitis, are fundamentally important for the provision of support for the cervical lordosis and the cervical joints (Mayoux-Benhamou et al., 1994; Conley et al., 1995; Vasavada et al., 1998), it was concluded that a change in the feed-forward response might leave the cervical spine vulnerable to strain (Falla et al., 2004d).

7. Implications for rehabilitation In summary, contemporary research has demonstrated impairment in the deep cervical muscles, which are considered to be functionally important for joint support and control (Jull, 2000; Falla et al., 2004c, d), deficits in muscle co-ordination which could result in poor support and potential overload on cervical structures (Jull, 2000; Falla et al., 2004a), insufficiency in the pre-programmed activation of cervical muscles (Falla et al., 2004d), inefficient neuromuscular activation (Falla et al., 2004b), and greater fatigability of superficial cervical muscles in people with chronic neck pain (Gogia and Sabbahi, 1994; Falla et al., 2003b,


2004e). In consideration of the evidence, it would seem apparent that there is a need for specificity when prescribing therapeutic exercise in the management of people with neck pain. There is some evidence to indicate that deficits in the motor system occur early in the history of onset of neck pain (Sterling et al., 2003) and does not resolve automatically with lessening or resolution of symptoms (Jull et al., 2002; Sterling et al., 2003). This would suggest that therapeutic exercise forms an essential component of the rehabilitation of patients with neck pain, as a reduction of pain alone would seem insufficient to fully restore muscle function. Moreover, it emphasizes the importance of early rehabilitation of muscle function in people with neck pain disorders. When developing exercises for treatment, it is necessary to have an understanding of abnormalities in the muscular system associated with painful dysfunctional joints. The results of recent research have significantly advanced our understanding of the impairment in the deep and superficial cervical flexor muscles in patients with neck pain syndromes. This knowledge provides the foundation to further develop and evaluate specific exercises for the management of this condition. Based on the muscle deficits considered to occur in neck pain, two types of exercise programs have been proposed in the literature to address cervical flexor muscle impairment. These two types of exercise programs are focused on two different functional requirements. The first exercise regime consists of general strengthening and endurance exercises for the neck flexor muscles (Berg et al., 1994; Highland et al., 1992; Jordan et al., 1998; Bronfort et al., 2001). These exercises involve high load training and thus recruit all the muscle synergists that is, both the deep and superficial muscles. For example, strengthening the neck flexor muscles is achieved by performing a head lift manoeuvre which would recruit all muscles capable of contributing to this action including, SCM, AS, longus colli and longus capitis. A typical exercise program would train the cervical flexors with the controlled head lift exercise and focus on training endurance and increasing the number of repetitions. Although several studies have reported a reduction in pain and improvement in function with this style of exercise (Highland et al., 1992; Berg et al., 1994; Bronfort et al., 2001), critical reviews and meta-analyses have generally concluded that further well-designed randomized controlled trials are warranted (Aker et al., 1996; Kjellman et al., 1999; Panel, 2001). The second exercise regime has been designed to focus on the muscle control aspects and aims at improving control of the muscles within the neck flexor synergy (Jull et al., 2004a). In contrast to more traditional high load strength and endurance exercises, low load exercise is used to train the coordination between the layers of

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neck flexor muscles. With this protocol, patients perform and hold progressively inner ranges of C-CF while trying to minimize activation of the superficial flexors. This exercise approach is based on biomechanical evidence of the functional interplay of the deep and superficial neck muscles and on physiological and clinical evidence of impairments in these muscles in neck pain patients. The efficacy of this emphasis on retraining the C-CF action in association with similar exercises for the shoulder girdle was tested recently in a randomized controlled clinical trial of physiotherapy management for cervicogenic headache (Jull et al., 2002). The results indicated that the specific exercise program significantly reduced the frequency of headache and neck pain and results were maintained in the long term at the 12-month follow-up. General strengthening exercises are not recommended in the early stages in this exercise approach as it is considered that general exercise will not necessarily address the dysfunction between the deep and superficial muscles (Jull, 2000). Thus specific emphasis is first placed on reeducating the deep and postural muscles and general strengthening exercises are only introduced once the imbalance between the deep and superficial neck synergists has been addressed. However, the results of recent research have created an interesting situation. There is evidence of reduced activation capacity of the DCF muscles with concurrent increased activity in the superficial muscles. Conversely, the superficial muscles have demonstrated greater fatigability and there is evidence of less strength. Therefore, there is some indication that both exercise regimes may be beneficial in the management of cervical muscle dysfunction in neck pain patients. Although clinical trials of both exercise regimes have produced results to suggest a decrease in neck pain, the physiological mechanisms of efficacy of cervical flexor muscle retraining regimes remain uncertain. For example, an improvement in DCF muscle activation would be expected following an exercise program based on retraining the activation capacity of the deep muscles. However, would this program influence the fatigability or neuromuscular efficiency of the superficial cervical flexor muscles? Similarly, we would expect a training regime focused on high load resistance training to enhance superficial cervical flexor muscle strength and reduce fatigability, but would it alter the neuromotor control of the DCF muscles? There is a paucity of good clinical studies regarding the efficacy of therapeutic exercise in neck pain patients, precluding any consensus on the most effective exercise prescribed. Although both exercise regimes are based on sound theoretical rationale, the mechanism of efficacy for either program is unclear. Further research is warranted to evaluate the physiological factors that change with each exercise intervention and to compare the different exercise


D. Falla / Manual Therapy 9 (2004) 125–133

modalities in order to identify the most effective means to induce these changes. This work is currently underway.

8. Conclusion In recent years, research has started to unravel the complexity of muscle impairment, which occurs in people with neck pain disorders. These findings have considerable implications for the prescription of therapeutic exercise. Whilst knowledge of the pathophysiology underlying cervical muscle dysfunction remains somewhat imprecise, the results of recent research have contributed greatly to our understanding of the impairment in the cervical muscles in people with neck pain, which has lead to an improved understanding and direction for the management of this condition. Further research is now necessary to clarify the physiological mechanisms of efficacy of cervical muscle retraining to ensure evidence based, optimal practice is embraced in modern practice.

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Falla D, Rainoldi A, Merletti R, Jull G. Myoelectric manifestations of sternocleidomastoid and anterior scalene muscle fatigue in chronic neck pain patients. Clinical Neurophysiology 2003b;114(3):488–95. Falla D, Bilenkij G, Jull G. Chronic neck pain patients demonstrate altered patterns of muscle activation during performance of a functional upper limb task. Spine 2004a, 29(13):in press. Falla D, Jull G, Edwards S, Koh K, Rainoldi A. Neuromuscular efficiency of the sternocleidomastoid and anterior scalene muscles in patients with neck pain. Disability and Rehabilitation 2004b, in press. Falla D, Jull G, Hodges P. Neck pain patients demonstrate reduced activation of the deep neck flexor muscles during performance of the cranio-cervical flexion test. Spine 2004c, in press. Falla D, Jull G, Hodges PW. Feedforward activity of the cervical flexor muscles during voluntary arm movements is delayed in chronic neck pain. Experimental Brain Research 2004d, in press. Falla D, Jull G, Rainoldi A, Merletti R. Neck flexor muscle fatigue is side specific in patients with unilateral neck pain. European Journal of Pain 2004e;8(1):71–7. Falla D, Rainoldi A, Jull G, Stavrou G, Tsao H. Lack of correlation between sternocleidomastoid and scalene muscle fatigability and duration of symptoms in chronic neck pain patients. Neurophysiologie Clinique 2004f, in press. Falla D, Rainoldi A, Merletti R, Jull G. Spatio-temporal evaluation of neck muscle activation during postural perturbations. Journal of Electromyography and Kinesiology 2004g;14:463–74. Gogia PP, Sabbahi MA. Electromyographic analysis of neck muscle fatigue in patients with osteoarthritis of the cervical spine. Spine 1994;19(5):502–6. Gurfinkel VS, Lipshits MI, Lestienne FG. Anticipatory neck muscle activity associated with rapid arm movements. Neuroscience Letters 1988;94(1–2):104–8. Hallgren RC, Greenman PE, Rechtien JJ. Atrophy of suboccipital muscles in patients with chronic pain: a pilot study. Journal of the American Osteopathic Association 1994;94(12):1032–8. Harms-Ringdahl K, Ekholm J, Schuldt K, Nemeth G, Arborelius UP. Load moments and myoelectric activity when the cervical spine is held in full flexion and extension. Ergonomics 1986;29(12):1539–52. Highland T, Dreisinger T, Vie L, Russell G. Changes in isometric strength and range of motion of the isolated cervical spine after eight weeks of clinical rehabilitation. Spine 1992;17(Suppl 6): S77–82. Hodges PW, Richardson CA. Inefficient muscular stabilization of the lumbar spine associated with low back pain. A motor control evaluation of transversus abdominis. Spine 1996;21(22): 2640–50. Janda V. Muscles and motor control in cervicogenic disorders: assessment and management. In: Grant R, editor. Physical therapy of the cervical and thoracic spine. New York: Churchill Livingstone; 1994. p. 195–216. Jordan A, Bendix T, Nielsen H, Hansen F, Host D, Winkel A. Intensive training, physiotherapy, or manipulation for patients with chronic neck pain. Spine 1998;23:311–9. Jull G, Barrett C, Magee R, Ho P. Further clinical clarification of the muscle dysfunction in cervical headache. Cephalalgia 1999;19(3): 179–85. Jull G, Trott P, Potter H, Zito G, Niere K, Shirley D, Emberson J, Marschner I, Ricardson C. A randomized controlled trial of exercise and manipulative therapy for cervicogenic headache. Spine 2002;27(17):1835–43. Jull G, Falla D, Treleaven J, Sterling M, O’Leary S. A therapeutic exercise approach for cervical disorders. In: Grieve’s modern manual therapy: the vertebral column, 2004a, in press. Jull G, Kristjansson E, Dall’Alba P. Impairment in the cervical flexors: a comparison of whiplash and insidious onset neck pain patients. Manual Therapy 2004b;9:89–94.

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ARTICLE IN PRESS



Systematic Review

The centralization phenomenon of spinal symptoms—a systematic review Alessandro Ainaa, Stephen Mayb,*, Helen Clarec b

a Studio di Riabilitazione DTM, Milano, Italy Sheffield Hallam University, Collegiate Crescent Campus, Collegiate Crescent, Sheffield S10 2BP, UK c School of Physiotherapy, Sydney University, Australia

Received 20 July 2003; received in revised form 3 December 2003; accepted 4 March 2004

Abstract The centralization phenomenon was first described 20 years ago. It refers to the abolition of distal pain emanating from the spine in response to therapeutic exercises. Since then a number of papers on the subject have been published. A review of current knowledge is appropriate. Selection criteria were established prior to a computer-aided search for published papers. Two reviewers independently extracted data and checked quality; a third reviewer resolved any disagreements. A narrative review was conducted based on the findings. The review primarily considered prevalence, reliability of assessment, and prognostic significance. These have been most commonly reported, and are important to establish the clinical worth of this symptom response. Fourteen studies were identified. Quality of studies varied; prognostic studies were given a mean score of 3.3 out of 6 by using established quality criteria. The prevalence rate of pure or partial centralization was 70% in 731 sub-acute back patients, and 52% in 325 chronic back patients. It is a symptom response that can be reliably assessed during examination (kappa values 0.51–1.0). Centralization was consistently associated with a range of good outcomes, and failure to centralize with a poor outcome. Centralization appears to identify a substantial sub-group of spinal patients; it is a clinical phenomenon that can be reliably detected, and is associated with a good prognosis. Centralization should be monitored in the examination of spinal patients. r 2004 Elsevier Ltd. All rights reserved.

1. Introduction Back and neck pain are extremely common symptoms, but they are symptoms only—the majority of spinal pain is said to be non-specific (Spitzer et al., 1987; AHCPR, 1994; CSAG, 1994). Non-specific spinal pain has no obvious diagnostic, prognostic or treatment indicators and treatment is something of a lottery dependent on which clinician is seen (Deyo, 1993; Cherkin et al., 1994; Van Tulder et al., 1997). Clinicians collect a range of clinical data during examination, including observational and palpatory findings supposedly to guide management. However there is evidence that this information is unable to indicate an appropriate management strategy (Dreyfuss et al., 1996; Levangie, 1999a; Hestboek and Leboeuf-Yde, 2000; Leboeuf-Yde et al., 2002). Identifying clinical findings that could guide treatment strategies is clearly desirable. *Corresponding author. Tel./fax: +44-114-221-7303. E-mail address: [email protected] (S. May). 1356-689X/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2004.03.004

Finding predictors of chronicity and disability after an acute attack of back pain is an important aim of primary care research (Borkan et al., 1998). Identification of such patients at an early stage would allow for the targeting of more intensive and costly interventions to those more likely to benefit from them most (Haldorsen et al., 2002). There has been considerable research into factors that may predict poor outcomes (Chavannes et al., 1986; Lanier and Stockton, 1988; Goertz, 1990; Hasenbring et al., 1994; Burton et al., 1995; Gatchel et al., 1995; Hazard et al., 1996; Smedley et al., 1998; Thomas et al., 1999; Potter et al., 2000), which has explored a wide range of individual, clinical and psychosocial factors. The relative importance of different factors remains unclear, but psychosocial factors are thought to have a dominant role in predicting future disability and clinical factors a limited role (Pincus et al., 2002). Psychological factors that are thought to be important include attitudes, cognitions, fear-avoidance towards pain, depression, anxiety and distress (Linton, 2000).

ARTICLE IN PRESS A. Aina et al. / Manual Therapy 9 (2004) 134–143

The phenomenon of centralization was first recognized by McKenzie in the 1950s and after much experimentation and verification was described in the literature (McKenzie, 1981). It is the process by which pain radiating from the spine is sequentially abolished, distally to proximally, in response to therapeutic positions or movements; and includes reduction and abolition of spinal pain. Centralization can occur in the lumbar, cervical, and thoracic spine (McKenzie, 1981, 1990). The opposite symptom response—a distal spread of pain into the limb is termed peripheralization. The symptom modification of centralization, which may occur during physical examination, is potentially important, as this response may guide clinicians in their management of non-specific spinal problems. Centralization may indicate the appropriateness of specific, rather than generalized exercises, and allow for the confident selection of mobilization or manipulation techniques (Lisi, 2001). In the absence of other clinical indicators for management of non-specific spine pain centralization may provide practitioners with a simple, yet valuable tool. Furthermore the phenomenon of centralization may act as a clinical predictor of good or bad outcomes. This would allow the identification of those patients who may need more involved interventions. Centralization was not evaluated in the scientific literature until 1990 (Donelson et al., 1990; Kilby et al., 1990), since which time there have been a number of studies. These have been of variable quality and therefore a systematic review of the available literature was deemed necessary in order to clarify the current documented knowledge regarding the value of this clinical phenomenon.

2. Methods A literature search was made on Medline, CINAHL, Embase and PEDro, start dates varied on different databases up to 2002 (key words: centralization/ centralization, and spine, and lumbar, and cervical). This was supplemented by a manual search of the references. Studies had to meet the following criteria: 1. 2. 3. 4.

The study involved centralization. The study subjects suffered from back or neck pain. The study was a controlled trial or a cohort design. Published in peer-reviewed journal, and not an abstract. 5. The article was written in English. One author (AA) conducted the initial search; the predetermined selection criteria were applied by a second author (SM). Data abstraction and quality assessment was conducted independently by two authors (AA, SM);

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disagreements were settled by negotiation with the third author (HC). The main focus of the review was upon prevalence rate, prognostic value and reliability of evaluation of centralization. The initial review of articles available revealed these to be issues that had been commonly investigated, but also issues that are important in establishing the clinical utility of this phenomenon. Despite the heterogeneity of study design most of the studies recruited a sample of back pain patients and estimated the prevalence rate of centralization in their population. Clinically therefore the studies were similar because of the patient sample, but dissimilar in study design. The only data extracted on which a metaanalysis could therefore be performed were the prevalence rates (mean and range) from these similar patient populations. Consideration was also given to the operational definition of centralization, the type of exercise, posture or technique used to induce centralization (the loading strategy), and the external diagnostic validity. Quality issues to be considered were sample size and standardization of assessment. One element of this was the use of an overlay template, which is described elsewhere (Donelson et al., 1991; Long, 1995). Briefly, a body chart filled in by the patient marking all areas of pain is covered by a transparent body chart with a scoring grid; with most distal pain scoring highest. This allows blinded assessment of patients’ pain patterns. To assess methodological quality in prognostic studies criteria were adapted from Laupacis et al. (1994) (Table 1). There are no widely agreed quality criteria for assessing prognostic studies (Altman, 2001). However discussion of the issue focuses on the same aspects of study design: patient sample, follow-up of patients, outcome, prognostic variables and analysis; and much the same quality criteria have been used (Laupacis et al., 1994; Hudak et al., 1996; Altman, 2001). Laupacis et al. (1994) failed to provide explicit detail for 2 of the criteria (C and D), but more detail was provided by Hudak et al. (1996). These were made explicit in the following ways: sufficient length of follow-up was defined as 1 year; sufficient numbers of follow-up was defined as more than 85% of initial cohort. These cut off points were selected to ensure an adequate follow-up period that addressed the known natural history of back pain (Abbott and Mercer, 2002), and an adequate follow-up sample, and were derived from another set of criteria (Hudak et al., 1996). If studies came near to these set criteria half a point was given. Hudak et al. (1996) also provided levels of evidence: strong evidence partially or fully meeting all criteria; moderate evidence partially fulfilling most criteria; weaker evidence when studies failed to fulfil multiple criteria. Assessing methodological quality in the other studies was not possible due to the range of study designs that


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Table 1 Method score for studies about centralization and prognosis Reference

A

B

C

D

E

F

Total

Donelson et al. (1990) Long (1995) Karas et al. (1997) Sufka et al. (1998) Werneke et al. (1999) Werneke and Hart (2001) Total

1 0.5 0 0.5 1 1 4

0 1 0 0 1 1 3

0 1 0 0 0 1 2

0 0.5 0.5 0.5 0.5 0.5 2.5

1 1 1 0 1 1 5

0 1 1 0.5 0 1 3.5

2 5 2.5 1.5 3.5 5.5

Mean (SD)

3.3 (1.63)

A. Was the sample representative of the underlying population? B. Were they at a well-defined point in the natural history? C. Was the follow-up of sufficient length—1 year? D. Was there follow-up of > 85% of the sample? E. Was there blinded assessment of outcome? F. Were other prognostic factors equal or accounted for in analysis?

were retrieved, which were all relevant to the issue being reviewed. Studies were cross-sectional, reliability studies; prospective, randomized trials; and prospective cohort studies; some studies were experimental and some were descriptive. Heterogeneity of study design discounted the use of uniform quality criteria. After the initial review the following general principles were adopted relative to certain pertinent outcomes. For reliability studies Kappa gives a numerical value to clinicians’ ability to reproduce a test result: 0–0.2 poor, 0.2–0.4 fair, 0.4–0.6 moderate, 0.6–0.8 good, 0.8–1.0 very good reliability (Altman, 1991). Negative values represent reliability that is worse than chance agreement. Kappa values take chance agreement into account and thus are more appropriate for reliability studies than percentage agreement only. For clinically important changes in outcome measures guidelines for the interpretation of effect size suggest that up to 0.5 is small, and greater than 0.8 is large (Cohen, 1987). It has been suggested that a clinically important change in an 11-point pain rating scale for chronic pain should be about 18% (Farrar et al., 2001). Odds ratio (OR) is a means of comparing the odds or likelihood of an event in one group compared to another, for instance centralizers and non-centralizers. An interpretation of OR=1 is the same outcome in both groups, OR>1 is higher probability in that group, and ORo1 is lower probability in that group (Earl-Slater, 2002).

3. Results A total of 14 papers (13 separate studies) were retrieved that investigated or referred to the phenomenon of centralization, none before 1990 (Table 2). Seven studies investigated patient samples of less than one hundred and six more than one hundred. An overlay body template was used to standardize the assessment procedure in only 4 studies (Table 2). Five studies (six papers) investigated the prognostic value of centraliza-

tion and could be given a method score (Table 1). Quality scores ranged from 1.5 to 5.5, mean 3.3 (SD 1.63). Two studies provided strong evidence (Long, 1995; Werneke and Hart, 2001), one moderate (Werneke et al., 1999), and 3 studies weak evidence (Donelson et al., 1990; Karas et al., 1997; Sufka et al., 1998) according to Hudak et al. (1996). Most common study limitations were short-term follow-up and patient attrition greater than 15%; also samples were not always at a well-defined point in natural history and sometimes failed to include other prognostic variables. 3.1. Definitions of centralization There was consensus around the core definition of centralization—the abolition of distal pain in response to the deliberate application of movements or postures. If pain is only in the back this is centralized and then abolished. Some authors added additional components to McKenzie’s original definition—Fritz et al. (2000) included a change in neurological signs and symptoms, and several studies included a reduction in intensity of the most distal symptoms in the definition (Delitto et al., 1993; Erhard et al., 1994; Karas et al., 1997). Werneke et al. (1999) applied a stricter definition: centralization occurred only in the clinic, and progressed sequentially toward the spine on each occasion until all symptoms were abolished. Werneke et al. (1999) also described a partial centralization group, in which changes in distal symptoms occurred, but less completely or not on each visit. 3.2. Prevalence In a meta-analysis of 1056 patients in ten studies (Table 3) centralization occurred in 681 patients (64.5%). In 731 patients with predominantly acute or sub-acute back pain (less than 7 weeks) 511 centralized (70%); in 325 patients with chronic back pain 170 centralized (52%). In individual studies prevalence of


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Table 2 Studies related to centralization Reference

Study design

Sample

Sample frame

Purpose related to centralization

Use of template

Kilby et al. (1990) Donelson et al. (1990)

Cross-section Descriptive, retrospective

41 87

Reliability Prognosis. Prevalence

No No

Williams et al. (1991) Donelson et al. (1991)

Prospective, randomised Prospective, randomised

207 145

Loading strategy Loading strategy

Yes Yes

Delitto et al. (1993) Erhard et al. (1994) Long (1995)

Prospective, randomised Prospective, randomised Descriptive, prospective

24 24 223

Selection criterion for trial Selection criterion for trial Prevalence. Prognosis

No No Yes

Karas et al. (1997) Donelson et al. (1997)

Descriptive, prospective Comparison study

126 63

Prevalence. Prognosis Criterion validity

No No

Sufka et al. (1998)

Descriptive, prospective

36

Single PT dept Private orthopaedic practice Multi-centre PT clinics International multi-centre PT clinics PT clinic PT clinic Work hardening programme Rehabilitation programme Tertiary centre for invasive testing PT clinic

No

Werneke et al. (1999)


Fritz et al. (2000)

Cross-section

289 NP&LBP Video

Prevalence. Prognosis. Reliability Prevalence. Prognosis. Reliability Reliability

No

Werneke and Hart (2001)


Prognosis

Yes

Kilpikoski et al. (2002)

Cross section

Reliability

No

187 LBP (84%) 39

2 PT clinics McKenzie assessment methods Parts of 12 patient assessments Long-term follow-up (12 months) Hospital patients from wider study

Yes

NP=neck pain, LBP=low back pain. PT=physical therapy.

centralization ranged from 31% (Werneke et al., 1999) to 87% (Donelson et al., 1990; Kilpikoski et al., 2002). In the study with the lowest rate 77% of all patients were classified in either the complete or partial centralization categories (Werneke et al., 1999). So the true range of complete or partial centralization across the studies is between 47% and 87%. Only one study included cervical problems in their cohort. Werneke et al. (1999) classified 25% of 66 neck pain patients in the centralization category and 46% in the partial centralization category. 3.3. Centralization and prognosis Six papers investigated the prognostic value of centralization by comparing the outcomes of centralizers with non-centralizers, which demonstrated several significant differences (Table 3). Centralization was correlated with good/excellent overall outcomes, greater reduction in pain intensity, higher return to work rates, greater functional improvement, and less continued healthcare usage (Donelson et al., 1990; Long, 1995; Sufka et al., 1998; Karas et al., 1997; Werneke et al., 1999; Werneke and Hart, 2001). Two studies found a lack of significant difference in Oswestry scores between centralizers and non-centralizers (Long, 1995; Sufka et al., 1998). Oswestry is a validated, self-reported, back specific functional disability questionnaire (Fairbank et al., 1980). One study

found a high Waddell score to be a more significant predictor of return to work than centralization (Karas et al., 1997). This score is derived from a collection of eight signs that are said to be indicative of non-organic pathology (Waddell et al., 1980). Werneke et al. (1999) found a significant difference in the number of treatment sessions between the centralization group (3.9) and the partial centralization (7.7) and non-centralization groups (8). However both centralization and partial centralization groups had significantly greater improvements in pain and function than the non-centralization group. Multiple independent variables were gathered at baseline, including demographic, historical, work and psychosocial factors; and patients were reviewed at 1 year (Werneke and Hart, 2001). In a multivariate analysis that included all independent significant variables only failure to achieve centralization and leg pain at intake were significant for predicting chronic back pain, disability, return to work, and healthcare usage at 1 year (Table 3). 3.4. Reliability of detection of centralization Five studies considered whether clinicians were reliable in detecting centralization (Kilby et al., 1990; Sufka et al., 1998; Werneke et al., 1999; Fritz et al., 2000; Kilpikoski et al., 2002). Three studies did so in a small group of patients, with only two or three therapists (Kilby et al., 1990; Werneke et al., 1999;


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Table 3 Prevalence and prognostic association of centralization Reference

N

Patient description

%C

Prognostic association of centralization

Donelson et al. (1990)

87

Acute 61%, sub-acute 17%, chronic 22%

87%

Correlation between centralization and good/excellent outcome (Po0.001), non-centralization and poor/fair outcome (Po0.001)


145

47%

Delitto et al. (1993) Erhard et al. (1994) Long (1995)

24 24 223

Acute 23%, sub-acute 38%, chronic 39% Acute 100% Sub-acute 100% Chronic 100%, Not working 100%

61% 55% 47%

Karas et al. (1997)

126

Acute and chronic, Not working 100%

73%

Donelson et al. (1997) Sufka et al. (1998)

63 36

49% 69%

Werneke et al. (1999)

289

Chronic 100%, Not working 70% Acute 16%, sub-acute 42%, chronic 42%. Back pain 77%, neck pain 23%. Acute 100%, Not working 37%

Werneke and Hart (2001)

187

Reviewed at 1 year—back pain only

77% (A+B)

Kilpikoski et al. (2002)

39

Chronic 100%

87%

Total–N (%)

1056

Greater reduction in pain intensity (o0.05), higher return to work rate (P=0.034) More frequent return to work (P=0.038)

A: 31% B: 46%

Greater functional improvement (P=0.015) 1: Fewer visits (Po0.001). 1+2: Greater improvements in pain (Po0.001), and function (Po0.001) Non-centralization predicted work status, function, health care use (Po0.001), and pain intensity (P=0.004)

681 (64.5%)

% C=proportion in which centralization occurred. Werneke et al. (1999), Werneke and Hart (2001): A=centralization, B=partial centralization (see text).

Kilpikoski et al., 2002); one study did not provide details (Sufka et al., 1998). Kilby et al. (1990) asked a broader question, ‘Do repeated movements decrease, abolish or centralize the pain?’ Fritz et al. (2000) used a large number of therapists who watched the same video containing edited parts from 12 examinations. Percentage agreement was high in all studies (88% to 100%). Kappa values were 0.51 (Kilby et al., 1990), 0.92 and 1.0 (Werneke et al., 1999), 0.82 and 0.76 for graduate and student therapists (Fritz et al., 2000), and 0.7 (Kilpikoski et al., 2002).

3.5. Loading strategy and centralization Centralization occurs during the physical examination in response to exercises, postures or mobilization. The type of loading strategy that was used to induce centralization was the focus of three studies (Donelson et al., 1990, 1991; Williams et al., 1991). When using exercises or postures only in the sagittal plane extension loading is significantly more effective at achieving centralization than flexion, and flexion is more likely to cause peripheralization (Table 4) (Donelson et al., 1991; Williams et al., 1991). Donelson et al. (1990) utilized exercises in sagittal and frontal planes and achieved centralization in 87%.

Table 4 Loading strategy associated with centralization Reference

N

Patient population

Extension/ lordosis

Flexion/ kyphosis

Williams et al. (1991)

210

Acute 24%,

C 56%a

C 10%a

P 6%a

P 24%a

145

sub-acute 41%, chronic 35%. Acute 23%,

C 40%

C 7%


Sub-acute 38%, Chronic 39%. C=centralization, P=peripheralization. a Only pain below knee.

3.6. Diagnostic implications of centralization Only one study examined the criterion validity of centralization with a blinded comparison between a mechanical evaluation and discography (Donelson et al., 1997). Patients displaying centralization or peripheralization were significantly more likely to have a positive discography than patients with non-centralization. A competent annulus was recorded in 91% (Po0.001) of those with centralization and a positive discogram, compared to 54% of those with peripheralization and a positive discogram.


4. Discussion In this review the authors evaluated the evidence concerning the centralization phenomenon, which was first reported by McKenzie (1981). Publications began in 1990, since when 14 studies have documented or referred to centralization. McKenzie (1981, 1990) reported that the phenomenon could be used to guide therapeutic management, and suggested a good prognosis. Potentially this clinical phenomenon may have both therapeutic and prognostic implications. If this potentially important symptom modification is to be used in assessment certain attributes must be documented. For it to be of clinical utility it must occur in a substantial proportion of those with spinal pain, its definition must be consistent across groups, the phenomenon must be identified reliably, and its identification must be worthwhile for management, prognostic or diagnostic purposes. From this review it appears that centralization is a common clinical occurrence in patients with acute or chronic lumbar symptoms, which has been documented in 47% to 87% of cohorts in 10 separate studies. The studies were consistent in the core definition—the abolition of distal limb pain in response to therapeutic loading strategies. Four out five studies found that evaluation of centralization can be performed with good or very good reliability. These findings suggest that centralization can be used to identify a sub-group of the back pain population consistently and reliably. These are important attributes for any clinical phenomenon that is to be used in practice. This review found the kappa values for centralization to range from 0.51 to 1.0. Historically palpation findings have been used to guide management. A selection of studies investigating the reliability of various palpation techniques for the lumbar spine and sacro-iliac joint demonstrated kappa values between 0.025 and 0.30 (Van Deursen et al., 1990; Binkley et al., 1995; Lindsay et al., 1995; McKenzie and Taylor, 1997; Meijne et al., 1999; Vincent-Smith and Gibbons, 1999; O’Haire and Gibbons, 2000). Such a comparison is clearly far from systematic or comprehensive, but it does appear to highlight dramatic differences in the reliability of 2 approaches to assessment. It would appear then that centralization allows reliable recognition of a substantial sub-group of the back pain population. However does its detection during assessment provide an important marker for outcome, management or diagnosis? This review demonstrated that centralization is consistently associated with a range of good outcomes in 6 studies relating to pain, function, return to work, and decreased healthcare usage (Donelson et al., 1990; Long, 1995; Karas et al., 1997; Sufka et al., 1998; Werneke et al., 1999; Werneke and Hart, 2001). We might question if statistically

139

significant differences between centralization and noncentralization groups are clinically significant. One study (Donelson et al., 1990) did not use established outcome measures, and 2 (Werneke et al., 1999; Karas et al., 1997) did not report absolute changes in pain, disability, or return to work thus making it difficult to evaluate the clinical importance of any change. The authors of this review found that the effect sizes for the partial and complete centralization groups (Werneke et al., 1999) ranged from 2.06 to 2.61 for pain and disability, compared to 0.51 to 1.02 for the non-centralization group (Werneke, 2003). Long (1995) reported pain changes and return to work rates as 16% and 68% in the centralization group compared to 6% and 52% in the non-centralization group. Sufka et al. (1998) reported mean improvements in the Spinal Function Sort of 51 in the centralization group and 15 in the non-centralization group, with 250 representing maximum functional disability. These studies suggest that there may be clinically important differences in outcome between centralizers and non-centralizers. However some studies do not allow a judgement about clinical importance to be made, some studies are ambiguous about the size of difference, and this issue requires further research. Only one study (Werneke and Hart, 2001) provided 1year follow-up, and provided odds ratios (OR) for different outcomes. Non-centralization gave an OR of 3.0 for high pain intensity, 9.4 for failure to return to work, 5.2 for interference with daily activities, and 4.4 for further health care. These substantial OR demonstrated a definite poorer long-term outcome using multiple measures; all of clinical importance, in patients who fail to demonstrate centralization (Werneke and Hart, 2001). Other studies did not report OR, nor provide data in a format that allowed their calculation, except for return to work (RTW) rates in Long (1995). The authors of this review calculated from Long (1995) the OR for RTW as 1.9 for the centralization group in a chronic back pain sample initially all off work. Further research needs to be conducted in this area using OR and long-term follow-up to confirm the relative value of centralization, but initial studies identify a clinical phenomenon that appears to have prognostic importance. Failure to achieve centralization has been shown to have greater prognostic significance than certain psychosocial factors, including job satisfaction, fear avoidance behaviour and depression, in one study (Werneke and Hart, 2001). This study is unusual in demonstrating a clinical factor to be more significant in predicting longterm outcomes than psychosocial factors. However it is important to bear in mind that multiple large-scale studies have confirmed the importance of psychosocial variables as prognostic factors (Chavannes et al., 1986; Lanier and Stockton, 1988; Goertz, 1990; Hasenbring et al., 1994; Burton et al., 1995; Gatchel et al., 1995;


A. Aina et al. / Manual Therapy 9 (2004) 134–143

Hazard et al., 1996; Smedley et al., 1998; Thomas et al., 1999; Potter et al., 2000). Although these 6 studies (Donelson et al., 1990; Long, 1995; Karas et al., 1997; Sufka et al., 1998; Werneke et al., 1999; Werneke and Hart, 2001) are consistent in identifying the prognostic value of centralization it must be noted that 3 of them provided only weak evidence, and one of moderate evidence, as defined by the criteria used to judge methodological quality (Hudak et al., 1996). Weaker studies suffered from short-term followup, lack of well-defined point in natural history and failure to include other prognostic variables; substantial patient attrition was a common failing in all studies. Two high-quality studies confirmed the prognostic importance of centralization (Long, 1995; Werneke and Hart, 2001). In the updated levels of evidence suggested for evaluating the quality of intervention studies from the Cochrane Collaboration Back Review Group (Van Tulder et al., 2003) the following levels are suggested: *

*

* *

*

Strong—consistent findings among multiple highquality randomized clinical trials (RCTs). Moderate—consistent findings among multiple lowquality RCTs and/or controlled clinical trials (CCTs) and/or one high RCT. Limited—one low-quality RCT and/or CCT. Conflicting inconsistent findings among multiple trials (RCTs and/or CCTs). No evidence—no trials.

These types of study designs are not transferable to a review of centralization; but using the equivalent levels of evidence for the studies we have reviewed would suggest moderate to strong evidence for the prognostic value and prevalence of centralization that we have described. Another important attribute for a clinical phenomenon is its ability to provide an indication of appropriate management. Contained within the definition of centralization is the assumption that it is induced during the physical examination, rather than occurring because of natural history. Ensuring centralization was clinically induced and that the initial symptom modification remained better was a reason for the stricter definition employed by Werneke et al. (1999). They identified 2 groups—centralization and partial reduction. In the first group changes were strictly clinically induced, but in the second changes occurred, but less completely or not on each visit. It is unknown if the partial reduction group improved due to natural history in an acute group of patients or due to the effect of exercises continued at home in between clinic visits. However as two studies (Long, 1995; Donelson et al., 1997) involving chronic patients recorded centralization prevalence of 48% it seems unlikely that natural history was entirely the reason. Further investigation is needed to confirm this.

In fact the distinction between the centralization and partial reduction groups although valid in terms of number of treatment sessions (3.9 versus 7.7), was not material to changes in pain and disability, which were similar—both significantly better than the non-centralization group. Failure to achieve symptom modification by the seventh visit identified patients who will do poorly in the long-term (Werneke et al., 1999). It would seem that it is the occurrence of centralization, rather than its speed or completeness that is important to outcome. Does centralization have diagnostic implications? Only one study has attempted to match centralization with a tissue-specific diagnosis in a group with chronic back pain (Donelson et al., 1997). This study demonstrates an association between centralization and discogenic pain, but obviously requires further verification. The link between symptom response generated by specific loading strategies and discogenic pain is reviewed in more detail elsewhere (Wetzel and Donelson, 2003). Centralization thus describes the abolition of distal symptoms in response to specific loading strategies, involving exercise, posture or mobilization. This symptom response is commonly found in acute and chronic back pain populations, and is consistently and reliably interpreted. It appears to be most helpful in guiding management and understanding prognosis. Limitations exist in the current literature on this topic; primarily the moderate quality of most studies, and several suggestions can be made to improve the quality of research. Past studies have involved small numbers, lack of consistent reporting mechanisms, lack of clear definition of sample, short-term follow-up, and lack of multiple prognostic variables. In acute populations it may be necessary to ensure that this symptom response is clinically induced, and not a product of natural history. Furthermore it is important to ensure that initial improvements are sustained and developed over the period of treatment. A strict operational definition of centralization that guaranteed these features was only described in one study (Werneke et al., 1999; Werneke and Hart, 2001). However, as discussed earlier, the distinction between partial and full centralizers impacted on number of treatment sessions, but not clinical outcomes. Follow-up has mostly been short-term, but longer follow-up has shown the prognostic importance of centralization after 1 year (Long, 1995; Werneke and Hart, 2001). None of the studies used a control group, other than the non-centralization group. Variations in treatment, initial symptom location, and duration of problems occurred across the different studies, and may be confounding factors when considering outcomes. Further research is needed into the comparative value of other prognostic indicators. Further descriptive studies


could also help to delineate more clearly the therapeutic forces needed to achieve centralization. Only one study (Werneke et al., 1999) has investigated this symptom response in the cervical spine. This demonstrated that it may be as common an occurrence in the cervical as in the lumbar spine, but further trials are needed to confirm this. As most of the work so far has been conducted in lumbar spine patients it would be inappropriate to automatically extrapolate this information to cervical spine patients. An issue in exploring this phenomenon is the operational definition that is used, and the fact that although the core definition has been consistent, there have been some discrepancies in previous research. Differences in definition include the addition of changes in symptom severity, rather than site, the addition of changes in neurological symptoms, and a distinction between centralising and full centralization. Werneke et al. (1999) gave clear-cut operational definitions of complete and partial centralization categories, which focus on a clinically induced change in symptom location, without consideration of symptom intensity, until all symptoms were abolished. The stricter definitions make research into the phenomenon more rigorous and should be used in future studies, as well as the overlay template, which allows for blinded judgement about symptom changes. Despite weaknesses in the quality of the literature all studies investigating this phenomenon are consistent in the direction of outcome, and the most rigorous study to date (Werneke et al., 1999; Werneke and Hart, 2001) confirms this trend with stricter operational definitions, longer follow-up, the inclusion of multiple potential prognostic variables, and appropriate data analysis. What is apparent from the current literature is that centralization is a common phenomenon that can be reliably assessed, and because of its association with good outcomes can be used to guide treatment strategies in certain patients. This is in marked contrast to other commonly used assessment procedures involving palpation or observation, which have frequently been found to be of poor reliability (Van Deursen et al., 1990; Binkley et al., 1995; Lindsay et al., 1995; McKenzie and Taylor, 1997; Meijne et al., 1999; Vincent-Smith and Gibbons, 1999; O’Haire and Gibbons, 2000). Tests of palpation use data that are subjectively determined by clinicians, which has not been shown to differentiate the back pain population from normal individuals (Dreyfuss et al., 1996; Egan et al., 1996; Levangie, 1999b; Lebouef-Yde et al., 2002), and has been unable to establish a lesion that is amenable to manipulation (Hestboek and Lebouef-Yde, 2000). In contrast to centralization commonly used tests based on palpation and observation of the spine appear to be poor determinants of management of spinal problems. A systematic review of these contrasting methods of

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physical examination is required to provide a more definitive evaluation of the comparative reliability of these different approaches. Finally it should be noted that the level of training and experience of the assessing clinician might well be important to maximize outcome. Reliability studies have shown that whereas therapists who were na.ıve to the McKenzie system are unreliable in determining symptom response (Riddle and Rothstein, 1993), those who are trained and experienced in the system can reliably assess symptom response (Razmjou et al., 2000, Kilpikoski et al., 2002).

5. Conclusion This review has found that the methodological quality of the literature in this area is mostly weak or moderate, however the findings are consistent and confirmed by 2 high-quality studies. Centralizing symptoms and full centralization are common clinical occurrences. It is a phenomenon that can be evaluated with good reliability, and is consistently associated with better outcomes than its absence. Centralization occurs frequently with extension exercises or postures, but also with other loading strategies. Non-centralization has been shown to be an important predictor of poor outcomes at one year in one study. This symptom response thus has important therapeutic and prognostic implications. In the light of the reliability with which centralization can be assessed, and its common occurrence and clinical importance it is recommended that it should be monitored routinely during spinal assessments and be used to guide treatment strategies.

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ARTICLE IN PRESS



Original article

Clinicians’ perceptions of minor cervical instability Kenneth Robert Niere*, Sarah Kathryn Torney Musculoskeletal Research Centre, School of Physiotherapy, La Trobe University, Victoria 3086, Australia Received 12 February 2003; received in revised form 25 July 2003; accepted 21 August 2003

Abstract Appropriate musculoskeletal physiotherapy management of spinal conditions requires recognition of clinical patterns in order to make a provisional diagnosis. This study aimed to assist the recognition of minor cervical instability (MCI) by surveying clinicians experienced in the management of neck conditions. A total of 153 Australian physiotherapists with postgraduate qualifications in manipulative physiotherapy and experience in the management of neck conditions completed a questionnaire that required them to indicate the importance of 15 clinical findings in the diagnosis of MCI. The responses were examined descriptively then subjected to factor analysis to identify possible groupings of findings. Clinical findings considered by greater than 50% of respondents to be either very important or vitally important in the diagnosis of MCI were: a history of major trauma; reports of the neck catching or locking or giving way; poor muscular control; signs of hypermobility on X-ray; excessively free end-feel on passive motion testing and unpredictability of symptoms. The factor analysis resulted in four distinct factors, each clinically interpretable. Therapists treating patients with neck conditions should at least consider the possibility of MCI when presented with any of the six findings reported above or with any of the groupings of findings identified by the factor analysis. r 2003 Elsevier Ltd. All rights reserved. Keywords: Cervical spine; Instability; Diagnosis

1. Introduction Physiotherapists are often involved in the diagnosis and treatment of patients who present with cervical spine pain and dysfunction. Although there are many potential causes of neck pain it has been proposed that loss of cervical spine stability may be a significant factor in some cases (Hensinger, 1986; Aspinall, 1990; Derrick and Chesworth, 1992). Major instability in the cervical spine usually arises when there is gross disruption of passive restraining influences, leading to bony impingement or compression of neural or vascular structures (White et al., 1976; Herkowitz and Rothman, 1984). This may lead to severe pain (Mazur and Stauffer, 1983; Sanchez-Martin, 1992), neurological symptoms and signs (Wiesel et al., 1978; Paley and Gillespie, 1986; Swinkels and Oostendorp, 1996) or vascular compromise (Paley and Gillespie, 1986; Sanchez-Martin, 1992). Diagnosis of major cervical instability is made on consideration of the history and clinical presentation and is usually able to be *Corresponding author. Tel.: 61-3-9479-5857; fax: 61-3-9479-5768. E-mail address: [email protected] (K.R. Niere). 1356-689X/$ - see front matter r 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S1356-689X(03)00100-0

confirmed by imaging. For example, Paley and Gillespie (1986) reported that poor landing technique by a high jumper caused repeated hyperflexion of her cervical spine that gradually stretched the ligaments of C5–6, leading to instability (demonstrated by radiography). Her condition was diagnosed only after she experienced paralysis and unconsciousness after further activities involving neck flexion. Prior to this her neck had felt stiff and painful, symptoms that did not ease following manipulative treatment. Panjabi (1992a) proposed that spinal stability is dependent on three interactive subsystems; passive, active and neural. The passive subsystem consists of the vertebrae and intervertebral discs, ligaments and joint capsules and the passive properties of the spinal muscles. The active subsystem comprises the spinal muscles and tendons while the neural subsystem consists of the force and motion transducers in the ligaments, tendons and muscles as well as the neural (motor and sensory) control centres. Panjabi (1992b, p. 394) defined clinical spinal instability as ‘‘....a significant decrease in the capacity of the stabilizing system of the spine to maintain the intervertebral neutral zones within the physiological limits so that there is no neurological

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dysfunction, no major deformity and no incapacitating pain’’. It has been proposed that cervical instability may exist where there is pain and disability due to lack of control over neutral zone motion without compromise of vascular or neural structures (Olin et al., 1982; Derrick and Chesworth, 1992; Niere and Selvaratnam, 1995). This has been described as minor cervical instability (MCI), and may demonstrate only subtle clinical features, potentially making it more difficult to diagnose (Olin et al., 1982; Paley and Gillespie, 1986). Clinical findings that have been proposed to be associated with minor cervical instability include: neck pain (Niere and Selvaratnam, 1995; Swinkels et al., 1996), complaints of catching or locking in the neck (Paley and Gillespie, 1986), reports of weakness, poor muscular control (Niere and Selvaratnam, 1995), altered range of motion (Derrick and Chesworth, 1992; Niere and Selvaratnam, 1995), and a history of major trauma (Niere and Selvaratnam, 1995) or repetitive microtrauma (Paley and Gillespie, 1986; Niere and Selvaratnam, 1995). Flynn et al. (1995) surveyed members of the Manipulative Physiotherapists’ Association of Australia and found that 97% claimed they treated patients with lumbar instability and that just over half were at least 70% confident at correctly diagnosing this condition. Examination findings that could be applicable to the cervical spine that were felt by the respondents to be important in diagnosing lumbar instability were a feeling of catching, locking or giving way, too free end-feel on palpation, a catch pain with active movement and the presence of spondylolisthesis (anterolisthesis in cervical spine). Loose end-feel, catching, locking and giving way have also been described by other authors in relation to lumbar instability (Grieve, 1982; Paris, 1985; Schneider, 1995) while Flynn (1995) also considered a history of major trauma or repeated micro trauma as important in recognizing lumbar instability. Appropriate musculoskeletal physiotherapy management of spinal conditions requires recognition of clinical patterns in order to make a provisional diagnosis. Once contraindications have been ruled out physical treatment is administered taking into consideration the diagnostic category and type and degree of musculoskeletal dysfunction present. Clinical trials of exercises to improve muscular stability for lumbar spine presentations thought to be associated with instability have been shown to be successful (Flynn et al., 1997; O’Sullivan et al., 1997). In these trials emphasis has been placed on retraining the neural and muscular subsystems to regain spinal stability. Unfortunately, as there is no ‘‘gold standard’’ for diagnosing MCI or even a commonly accepted set of clinical findings associated with MCI, this condition remains a clinically derived diagnostic hypothesis. If patterns of presentation could be identified for MCI, treatment could be guided towards

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retraining of the cervical neuro-muscular system to enhance the active and neural subsystems and hence cervical spine stability. The main aim of this study was to survey clinicians regarding MCI in order to identify clinical findings that the majority felt were important towards a diagnosis of this condition. Factor analysis, a statistical technique that analyses relationships between variables and summarizes these relationships by forming groups of related variables (factors), is often used to assist in the interpretation of large data sets. A further aim was to determine whether an exploratory factor analysis of the survey results could identify clinical reasoning patterns used by clinicians in the identification of MCI.

2. Method Ethical approval for this study was granted by the La Trobe University Faculty of Health Sciences Ethics Committee. 2.1. Participants Each member of the Victorian Chapter of the Manipulative Physiotherapists Association of Australia (now Musculoskeletal Physiotherapy Australia) was sent a questionnaire developed by the researchers. This group was chosen because of their relevant further education and their likely experience in treating cervical conditions. All Manipulative Physiotherapists surveyed had completed a masters or equivalent degree in Manipulative Physiotherapy after at least 2 years clinical practice and were obliged to participate in a mandatory continuing education scheme. 2.2. Questionnaires The questionnaires were developed using the FormPro V1.0 application programme (Beach Tech Corporation) to enable electronic reading of data. Fifteen clinical findings (see Table 1), reported in the literature to be present in MCI were used as the items for the questionnaire (Scher, 1978; Olin et al., 1982; Paley and Gillespie, 1986; Derrick and Chesworth, 1992; Niere and Selvaratnam, 1995). Minor Cervical Instability was defined on the questionnaire as: ‘‘an increase in the neutral zone associated with one or more segments within the cervical spine. This condition may be associated with a number of signs and symptoms but does not include severe incapacitating pain or symptoms indicative of spinal cord compression or vertebral artery disruption.’’ Respondents were asked to indicate the importance of each of the 15 findings in their diagnosis of MCI. The questionnaire utilized a five-point Likert scale with the


23 24 17 19 24 11 15 9 8 8 5 5 4 5 1 33 34 24 27 34 16 21 13 11 11 7 7 5 7 1 70 66 69 63 56 63 50 58 46 36 36 34 27 17 19 25 20 24 28 24 32 30 32 44 41 31 39 42 35 31

48 46 48 44 39 44 35 40 32 25 25 24 19 12 13

71 70 65 63 63 56 50 49 40 33 30 29 23 17 15

% % N N %

%

Responses ‘very’ or ‘vital’

descriptors ‘of no importance’, ‘of minor importance’, ‘somewhat important’, ‘very important’ and ‘vitally important’. The questionnaire also included an openended question seeking further comments on MCI, and a question designed to determine the therapist’s confidence in their diagnosis of MCI (on a five-point scale, from ‘‘not at all confident’’ to ‘‘very confident’’). A pilot study was undertaken with an earlier form of the questionnaire and minor modifications were made to arrive at the version used for the main study. Cronbach’s alpha, a measure of the internal consistency of the questionnaire was calculated to be 0.73 and supported the assumption that the questionnaire was measuring one underlying construct (MCI).

2.3. Procedure One hundred and ninety four questionnaires were posted. Those practitioners who did not return their questionnaires within 2 weeks were given a reminder telephone call. After a further 2 weeks without a reply another questionnaire was mailed.

36 29 34 40 34 46 43 46 63 59 45 56 61 50 45 0 1 0 4 3 1 7 4 3 11 8 10 4 14 16 History of major trauma Catching/locking/giving way Poor muscular control Excessively free end-feel with palpation Signs of hypermobility on X-ray Unpredictability of symptoms Spondylolisthesis History of repeated microtrauma Neck weakness (subjective) Traction spurs Altered range of motion Neck pain Muscle spasm Muscular atrophy Headaches

5 13 16 8 16 16 21 22 20 26 48 36 46 56 62 0 1 0 3 2 1 5 3 2 8 6 7 3 10 11

%

4 9 11 6 11 11 15 15 14 18 33 25 32 39 43

N N Finding

%

Of minor importance

N

2.4. Data analysis

Of no importance

Table 1 Frequency of responses in each category for each clinical finding

Somewhat important

Very important

Vitally important

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Descriptive analysis of the data included the investigation of the therapist’s confidence in their diagnosis of MCI, collation of extra comments and tabulation of the frequency of responses for each item. For the factor analysis a correlation matrix was formed using the raw scores for each item. Principal components analysis was performed and factors were extracted according to the Kaiser criterion (Eigenvalues >1.0). To improve the clarity of the factor matrix the factors were rotated using Varimax rotation. The task of factor interpretation was achieved by examining the underlying themes within each factor, and comparing these themes with the current literature regarding MCI. To aid in interpretation of the factors, eight Manipulative Physiotherapists with at least 7 years experience in the management of cervical conditions were mailed the results and were asked to comment upon any meaningful clinical patterns present. Their responses are reported in the discussion.

3. Results The questionnaire was completed and returned by 158 (81.4%) of the Manipulative Physiotherapists. Fig. 1 shows the frequency distribution for the question on clinician confidence in diagnosing MCI. The responses of the 13 therapists who were ‘‘not at all’’ confident were deleted from further analyses.

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70

Table 2 Other findings described as being important in diagnosing MCI

60 50

41 35

N

40 30 20

13 4

10 0 Not at all

Slightly

147

Somewhat

Moderately

Very

Level of confidence in ability to diagnose MCI

Fig. 1. Clinician confidence. Frequency histogram showing the level of confidence of respondents in their diagnosis of MCI.

Clinical finding

N

Apprehension when moving into neck extension Feeling of a ‘‘heavy head’’ Feels like ‘‘head is dropping off’’ Episodes with no precipitating cause Crepitis Feeling of a lump in the throat Difficulty returning from extension Poor response to previous treatment Good response to stabilising treatment Shoulder girdle weakness and atrophy Distinctive build/client (young females with long skinny necks) Other medical history

6 4 4 3 2 2 2 2 2 1 1 1

Table 3 Summary of variables that loaded strongly (0.4 or greater) on each factor Factor one

Factor two

Factor three

Factor four

Traction spurs Signs of hypermobility on X-ray Spondylolisthesis History of repeated microtrauma History of major trauma

Poor muscular control Neck weakness (subjective) Unpredictability of symptoms Catching/locking/ giving way Muscular atrophy

Headaches Neck pain Muscle spasm Muscular atrophy

Excessively free end-feel with palpation Altered range of motion History of major trauma

3.1. Importance of each variable Table 1 shows the frequency of responses in each category for each variable. Clinical findings considered by greater than 50% of respondents to be either very important or vitally important in the diagnosis of MCI were: a history of major trauma; reports of the neck catching or locking or giving way; poor muscular control; excessively free end-feel on passive motion testing; signs of hypermobility on X-ray and unpredictability of symptoms. Thirty clinicians provided additional signs and symptoms that they felt were important in their diagnosis of MCI (Table 2). 3.2. Factor analysis Missed responses were rare and comprised 0.7% of the total data set. As the missed responses appeared to be randomly distributed they were replaced by the mean values for the relevant variable. Calculation of itemtotal correlations detected no outliers or unduly influential variables. The correlation matrix indicated that the variables were moderately correlated and the score for Bartlett’s test of sphericity was 441.29 (Po0.00001), further indicating that the data were appropriate for factor analysis. Factor analysis with Varimax rotation resulted in the formation of four distinct factors (Table 3), explaining 53.6% of the total variance. Squared multiple correlations (SMCs) for all factors were equal to 1.00 (on a

scale of 0.00–1.00). A high SMC means that the variables define the factors well, and that an appropriate number of factors have been selected (Norusis, 1992).

4. Discussion 4.1. The importance of specific findings The specific findings that the majority (greater than 50%) of respondents thought were very important or vitally important in the diagnosis of MCI were: an excessively free end-feel with palpation; reports of catching or locking or giving way; poor muscular control; unpredictability of symptoms; history of major trauma and hypermobility on X-ray. It is proposed that clinicians should consider the possibility of MCI when a patient presents with one or more of these findings. It should be noted that the presence of spondylolisthesis (50%) and a history of repeated microtrauma (49%) were also commonly chosen as being very important or vitally important. Findings such as headaches, neck pain and muscle spasm were infrequently considered vitally or very important. This could be because these findings are not be specific to MCI, that is they may exist in many other cervical presentations as well as MCI. It should be remembered that the clinicians commented on each of the findings in isolation. It is the recognition and interpretation of patterns of findings that is integral to effective clinical reasoning (Higgs and Jones, 2000).


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Therefore, conditions such as MCI are more likely to be recognized by the presence of a number of related findings, possibly in conjunction with the absence of other findings. Consideration of the patterns formed by the factor analysis may assist in this process. 4.2. Factor analysis 4.2.1. Factor one (passive dysfunction) Factor one (hypermobility on X-ray, spondylolisthesis, history of repeated microtrauma, history of major trauma, traction spurs) may be associated with passive dysfunction of the stabilizing system of the spine. Spondylolisthesis (anterolisthesis) is strongly associated with passive dysfunction (Twomey and Taylor, 1995) while traction spurs (Macnab, 1978) and hypermobility (Jonsson et al., 1991) may both arise following damage to passive restraints. White et al. (1976) defined radiological instability of the cervical spine as greater than 3.5 mm of translation or an angular difference of 11 greater than adjacent segments. While these findings may certainly indicate problems with the passive subsystem and potential instability, static X-rays do not give an indication of the control of motion in the neutral zone, a factor pivotal in spinal stability (Panjabi, 1992b). Fluoroscopy is likely to be of greater value but its use is likely to be limited due to limited accessibility and unnecessary radiation exposure. It is possible that damage to the passive subsystem could arise following an episode of major trauma (Jonsson et al., 1991; Olson and Joder, 2001) or repeated microtrauma (Paley and Gillespie, 1986). The Manipulative Physiotherapists consulted on the clinical meaning of the factors indicated that factor one may represent post-traumatic hypermobility or instability, strengthening the hypothesis that factor one describes MCI. 4.2.2. Factor two (active dysfunction) The findings contributing to factor two (poor muscular control, subjective complaints of neck weakness, unpredictability of symptoms, catching/locking/ giving way and muscular atrophy) appear to be related to the subjective findings and presence of muscular dysfunction. The items loading on factor two appear to conform with the classification of spinal instability and comply with the theoretical profile of minor instability by relating well to findings reported from other regions of the body (Magarey and Jones, 1994; Ryan, 1994; Flynn et al., 1995; Prosser, 1995). Olson and Joder (2001) reported poor control and ‘‘shaking’’ on active cervical movement in a 32 year old woman with symptoms thought to be caused by cervical instability. The interpretation group believed that this factor represented ‘‘textbook’’ MCI. The strong influence of muscular findings associated with factor two leads to the

proposal that this factor reflects active dysfunction in MCI. 4.2.3. Factor three (upper cervical pattern) Factor three (headaches, neck pain, muscle spasm, muscular atrophy) appears likely to reflect MCI occurring within an upper cervical spine pattern. The upper cervical spine is capable of referring pain into the head (Bogduk, 1992) while muscular dysfunction is commonly encountered in cervical headache (Jull et al., 1999). It is therefore possible that segmental instability caused by damage to the stabilizing system of the cervical spine may be associated with muscle spasm, neck pain and cervical headache. Muscular atrophy may arise due to primary damage to muscular tissue, or as a result of disuse due to pain (Brukner and Khan, 1993). This muscular atrophy may compromise function of the active subsystem of the cervical spine, resulting in pain, headache and muscle spasm. 4.2.4. Factor four (movement abnormality) The findings loading on this factor (history of major trauma, excessively free end-feel with palpation, altered range of motion) relate well to current theory relating to classification of minor instability. Shippel and Robinson (1987) described the case of a 34 year old male who presented with neck pain, stiffness and muscle spasm after a whiplash injury and was shown to have ‘‘ligamentous instability’’ demonstrated by increased segmental range of motion on functional flexion/ extension X-rays. Panjabi et al. (1998a) hypothesized that many long-term whiplash symptoms are due to soft tissues which have been stretched beyond their elastic limit but not completely ruptured. In support of their claims Panjabi et al. (1998b) used a cadaveric model to show that whiplash-type injuries could cause increases in range of movement and neutral zone at upper and lower cervical levels. Dvorak et al. (1993) showed that chronic whiplash patients tended to exhibit increased cervical mobility on functional flexion/extension X-rays when compared to those of subjects with other neck conditions. Factor four may represent movement abnormality following an episode of major trauma, resulting in MCI. However, the group consulted regarding factor interpretation displayed uncertainty regarding the meaning of this factor, with most claiming to be unsure of the clinical pattern demonstrated. 4.3. Limitations The responses to the questionnaire and from the group interpreting the factors could have been either a reflection of their educational training or clinical reasoning patterns. Knowledge in this area may have been gained from formal undergraduate and postgraduate education, continuing education courses and


lectures and reflection upon clinical practice. The results are likely to be reflective of a mixture of all of these influences with variation between respondents. The respondents were limited to manipulative physiotherapists who were members of the Victorian branch of the Manipulative Physiotherapists Association of Australia (now Musculoskeletal Physiotherapy Australia). Different results may have been gained by surveying populations from other states, countries or disciplines. Operational definitions were not provided for the 15 items on the questionnaire and items such as ‘‘unpredictability of symptoms’’, ‘‘poor muscular control’’, ‘‘muscle atrophy’’ and ‘‘excessively free end-feel with palpation’’ may have been interpreted differently by the respondents. Similarly, it is possible that there may have been different interpretations of the definition of MCI given in the instruction sheet, more specifically in relation to severe, incapacitating pain or symptoms indicative of spinal cord compression or vertebral artery disruption. To be useful in diagnosis clinical tests need to be reliable and valid. Further research is required to determine how reliably the items are identified in clinical practice. Although the results of this study support the face validity of the findings in Table 1 for recognizing MCI, predictive validity is more difficult to ascertain because there is no ‘‘gold standard’’ to positively identify MCI. It should be reiterated that the aims of this study were to identify clinical findings that clinicians felt were important in the detection of MCI. The results should not be considered as definitive in the diagnosis of this condition but as possible indicators that part of the patient’s symptom complex could be due to decreased cervical spine stability. A limitation of the factor analysis in this study was that only 53.6% of the total variance was explained by the four factor solution, possibly indicating a lack of consistency in responses, a finding which may indicate decreased levels of agreement within the population studied. Also, interpretation of any exploratory factor analysis is a subjective process. Other clinicians and researchers may not interpret the factors as they have been presented in this paper. 4.4. Directions for further research Future research is important in order to validate the findings of this study. This may involve replication of this design, possibly incorporating additional symptoms or with different subject groups. The establishment of a gold standard for diagnosing MCI would be an important outcome of research in this area. However, given the likely difficulty in identifying a gold standard, the identification of groups of clinical findings that reliably predict the outcome of specific treatments would be a useful step towards this goal. Clinically based research to validate the results of the present study and investigate the effectiveness of treatment options could

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be designed along the lines of the study by Flynn et al. (1997). Other possible avenues of research include investigation into the validity of radiology in the diagnosis of MCI, the development and investigation of special tests to assess this condition, the effectiveness of various treatment options, and an investigation into the expected prognosis for patients with decreased cervical stability. The results of these research ideas may assist physical therapists and other health professionals in providing an effective service to clients thought to have symptoms caused by MCI.

5. Conclusion Based on the results of this study clinicians should be alerted to the possible presence of MCI in patients presenting with one or more of the findings thought by the respondents to be important in the diagnosis of MCI or by patterns of findings resembling any of the four factors. These results may aid clinicians in recognizing cases of minor cervical instability, a condition not clearly or extensively described in the literature. Additional information regarding possible manifestations of MCI will help clinicians to better understand this condition. Improved understanding should lead to more appropriate assessment and treatment with better treatment outcomes.

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ARTICLE IN PRESS



Original article

How common are side effects of spinal manipulation and can these side effects be predicted?$ Barbara Cagniea,*, Elke Vincka, Axel Beernaertb, Dirk Cambiera a

Department of Rehabilitation Sciences and Physiotherapy, Ghent University, DePintelaan 185, 6K3, Ghent 9000, Belgium b Postacademic Education in Manual Therapy, Ghent University, Belgium Received 17 October 2003; received in revised form 3 December 2003; accepted 4 March 2004

Abstract Little scientific support is available concerning usual and unusual reactions after spinal manipulation although such reactions are very common in clinical practice. Fifty-nine manipulative therapists were requested to enroll 15 consecutive patients attending for their first visit to receive spinal manipulation. These patients were asked to complete a questionnaire after this first visit that asked for possible risk factors for spinal manipulation and asked about any side effects after the manipulation. The participating practitioners were asked to note medical diagnosis, manipulated spinal region, number of treated areas and type of additional treatment. Four hundred and sixty five valuable responses were analysed. Two hundred and eighty three patients (60.9%) reported at least one post-manipulative reaction. The most common were headache (19.8%), stiffness (19.5%), local discomfort (15.2%), radiating discomfort (12.1%) and fatigue (12.1%). Most of these reactions began within 4 h and generally disappeared within the next 24 h. Women were more likely to report adverse effects than men ( Po0.001). Multivariate analysis showed that upper cervical manipulation (OR: 3.20; 95%CI: 1.89–7.77), use of medication (OR: 2.20; 95%CI: 1.31–3.69), gender (OR: 1.66; 95%CI: 1.01–2.75) and age (OR: 1.02; 95%CI: 1.00–1.05) were independent predictors of headache after spinal manipulation. The results of this study indicate that reactions to spinal manipulation may be relatively common but are benign in nature and of short duration. Although it is difficult to label side effects as a risk, it is important to differentiate those patients who are susceptible to side effects in order to inform them correctly. r 2004 Elsevier Ltd. All rights reserved.

1. Introduction Spinal manipulation as a treatment for musculoskeletal complaints has been practiced for centuries. The remarkable popularity of spinal manipulation contrasts with a disappointing lack of scientific investigations regarding its safety. Severe injuries may occur after spinal manipulation, mainly after treatment of the neck (cerebrovascular accidents), as well as in the mid-back (rib-fractures) and lumbar spine (cauda equina lesions) (Haldeman and Rubinstein, 1992; Powell et al., 1993; Assendelft et al., 1996; Di Fabio, 1999). Fortunately, the incidence of serious complications is generally considered to be low $

Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.math.2004.03.001 *Corresponding author. Tel.: +32-9-240-52-65; fax: +32-9-24038-11. E-mail address: [email protected] (B. Cagnie). 1356-689X/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2004.03.001

(Hurwitz et al., 1996; Klougart et al., 1996; Rivett and Milburn, 1996). However, relatively minor side effects of spinal manipulative therapy are common in clinical practice. Although therapists who regularly perform spinal manipulations probably know intuitively how to discern usual from unusual post-manipulative reactions in their patients, little scientific support is available that can confirm or refute such an experience. Therefore, no proper information can be given to the patient prior to a manipulative treatment. Although side effects cannot be labelled as major risks, it seems justifiable to inform patients about possible minor reactions after spinal manipulation. This is even more important as these reactions mainly occur after the patient has left the treatment room. Few studies have been published on these side effects (Senstad et al., 1996a and b, 1997; Leboeuf-Yde et al., 1997; Barrett and Breen, 2000; Ernst, 2001). Nevertheless, some efforts have been made to classify them.


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According to Senstad et al. (1996a), side effects are divided into common and uncommon reactions, based on frequency of occurrence. Common reactions include local discomfort, headache, fatigue and radiating discomfort, while uncommon reactions include dizziness, nausea, hot skin and other reactions. Attempts have been made to identify risk factors in order to predict adverse reactions to spinal manipulation. Risk factors that have been discussed in the literature include age, gender, migraine, hypertension, diabetes, smoking and oral contraceptives (Pattijn, 1991; Haldeman et al., 1999, 2002). Senstad et al. (1996a) have already investigated the influence of gender, age and treatment-related factors on the side effects of spinal manipulative therapy. To the best of our knowledge no other studies are available that include other possible predisposing factors that may increase the risk of side effects after spinal manipulation. Therefore, a prospective observational survey was designed and conducted with a variety of manipulative therapists in order to investigate the necessary characteristics to inform the patient properly.

and severity of symptoms. A list of possible reactions thought to occur after spinal manipulation was included in the survey. In addition, the questionnaire asked whether any reaction had caused difficulty in performing daily activities and how the patient felt 48 h after treatment. The questionnaire was first tested in a pilot study aimed at designing a suitable questionnaire that would enable patients to answer it without having to ask their practitioner further questions. After this piloting, the survey was integrated in the protocol. In a separate questionnaire, the practitioners were requested to note the medical diagnosis, the spinal region they treated, the number of spinal manipulations and the specific type of manipulation they performed. These questionnaires were also sent to the study centre. The questionnaires from the patients and therapists could be linked together by codes, but the names of the participating therapists were completely blinded for data analysis. Data collection started in December 2001 and continued for 4 months. 2.3. Statistical analysis

2. Subjects and methods 2.1. Subjects A prospective survey was conducted among manual physiotherapists, chiropractors and osteopaths in Belgium. Fifty registered practitioners of each profession were randomly selected and invited by letter to take part in the study. Twenty manual physiotherapists, 18 osteopaths and 21 chiropractors agreed to participate by sending back a reply card. Each of them received 15 questionnaires to hand to 15 new and consecutive patients at their first manipulative treatment session. To be included, patients had to be aged 18 or over, be new to the practice or consult for a new problem and should not have been manipulated for at least 12 months. 2.2. Study design The patients were asked to complete a questionnaire regarding risk factors and side effects within 48 h postmanipulation. Afterwards they returned it anonymously to the study centre in a pre-stamped and addressed envelope. The questionnaire consisted of two sections. The first ‘general’ section asked for personal data related to possible patient-related risk factors (see the appendix in the supplementary information). The second section asked if the patient had experienced any unpleasant reactions after the spinal manipulation and, if so, to report the type of this reaction, time of onset, duration

The data were analysed using the Statistical Package for the Social Sciences (SPSS) software (version 10.0). The results were analysed descriptively. When several types of reactions were recorded after one treatment, the most severe or the longest lasting of them was chosen if the analyses allowed only one symptom to be included. Univariate and multivariate analyses were performed to identify risk factors. Differences between groups were calculated through cross-tabulations. Risk factors associated with side effects in univariate analysis were entered into logistic regression models. Different models were tested. Forward stepwise was used in the present study. Forward selection begins with no predictors in the regression equation. The predictor variable that has the highest correlation with the criterion variable is entered into the equation first. The remaining variables are entered into the equation depending on the contribution of each predictor.

3. Results 3.1. Description of the study sample Fifty-one of 59 participating practitioners returned their questionnaires before the deadline (86.4%). An average of 12.5 questionnaires per therapist were distributed to patients, resulting in 639 questionnaires in total. This represents 83.5% of the optimal number of 765 questionnaires (51 multiplied by 15). The reasons for non-participating after having entered the study

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varied: two therapists handed in their data after the deadline, three said they did not have enough patients and three practitioners gave no reason. Four hundred and sixty five patients returned their questionnaires of which 465 ‘linked’ questionnaires (therapist and patient) were finally analysed. This represents 72.8% of the distributed questionnaires. According to the therapist questionnaires, there was no significant difference in diagnosis and treatment of the patients who did respond and those who did not. Two hundred and seventy one women (58.3%) and 194 men (41.7%) participated with an average age of 40.18 years (SD 12.88; range: 18–91). 47.1% were younger than 40, 45.8% were between 41 and 60 and 7.1% were older than 60 years of age. The medical diagnosis for which the patients received treatment were cervical dysfunction (39.23%) [cervicalgia (21.77%), cervico-brachialgia (6.22%), cervicogenic headache/vertigo (11.24%)], thoracic dysfunction (8.13%), lumbar dysfunction (38.76%) [lumbalgia (25.60%), sciatica (13.16%)], sacroiliac dysfunction (4.55%) and others (9.33%). Most of these complaints had a spontaneous onset (69.9%), whereas 16.8% were caused by trauma, 1.9% resulted after surgery, 2.8% had a congenital onset and 8.6% were work-related. 23.8% of the patients were smokers, 25.8% had smoked in the past and 50.4% had never smoked, 2% had diabetes, 2.2% osteoporosis, 6.5% hypertension, 14.4% migraine and 75.5% reported none of these disorders. 32.6% of the patients reported that they took medication regularly, such as analgesics (26%), antihypertensive agents (17.12%), antimigraine drugs (4.11%), antidepressants (6.85%), cholesterol-lowering medication (6.16%) and other medication (43.84%). 32.3% of the female respondents used oral contraceptives. The average number of manipulations per person during one session was two. In 28.5% of the cases three or more manipulations were performed during one session. Two manipulations were performed in 38.3% of the cases and only one spinal manipulation in 33.1% of the patients. Of a total of 930 recorded manipulations, 38.6% included the cervical spine, 25.7% the thoracic spine, 23.6% the lumbar spine and 12.1% the sacroiliac joint. 3.2. Side effects 3.2.1. Number and type of reactions Of the 465 patients who submitted their questionnaire 283 patients (60.9%) reported at least one reaction. Of this number, 62.9% mentioned two or more side effects. The different types of reactions and their frequencies are shown in Fig. 1. The most commonly reported side effect was headache (19.84%), followed by stiffness

dizziness 4%

nausea 3%

153 others 9%

headache 20%

muscle spasms 6%

fatigue 12%

radiating discomfort 12%

stiffness 19%

aggravation of complaints 15%

Fig. 1. Types and frequency of reactions following spinal manipulative therapy.

(19.46%), aggravation of complaints (15.18%), radiating discomfort (12.06%) and fatigue (12.06%). If several reactions were reported in the same questionnaire, the one that was experienced as the most severe or that lasted the longest was included in the analysis. Reports of muscle spasm (5.84%), dizziness (4.28%) and nausea (2.72%) were uncommon. 3.2.2. Onset, duration and severity of reactions 60.54% of the reactions started within 4 h after manipulation, and 63.96% had disappeared within the next 24 h. 19.37% of the reported reactions lasted more than 48 h after treatment. 14.29% of the side effects represented a slight discomfort, two out of three reactions were described as mild (26.47%) or moderate (38.66%) and 20.58% were defined severe. Side effects resulted in 26.6% of the patients mentioning an impaired performance of their daily activities. These activities included: housekeeping (39.2%), sport (32.8%), sleeping (32.8%) and work (45.6%). Despite the side effects, 66.9% of the patients reported that the complaints they were treated for improved within 48 h after the spinal manipulation. 3.2.3. Predictors of side effects Univariate analysis revealed that women were more likely to report adverse effects than men (Pp0.001). Women complained significantly more of stiffness (P ¼ 0:038), headache (P ¼ 0:016), fatigue (P=0.036) and local discomfort (P=0.030). Smokers registered significantly more headache after spinal manipulation than people who had never smoked (P=0.045) and patients who used medication on a regular basis reported significantly more headache after treatment than people who did not (P=0.011). The use of oral contraceptives did not show any difference in type of


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symptoms. People with a medical history of migraine experienced significantly more headaches than people without this complaint (Po0.001). In cases of only one area treated, manipulation of the cervical spine caused significantly more headache and fatigue than manipulations of the lumbar (P=0.007 and 0.037, respectively) and thoracic spine (P=0.037 and 0.037, respectively) only. The less common reactions such as dizziness (P=0.022) and nausea (P=0.031) were also significantly more present after cervical manipulation than lumbar and thoracic manipulation. In the cervical region, manipulation to the upper cervical spine caused significantly more headaches than lower cervical manipulation (P=0.004). The number of performed manipulations could not be associated with any of the outcome variables. Analysis between the three professions revealed (1) a lower number of manipulations per treatment session performed by osteopaths in comparison with the two other professional groups (P=0.000) and (2) a lesser number of cervical manipulations performed by osteopaths (P=0.000) and sacroiliac manipulations performed by manual physiotherapists (P=0.003). According to the side effects, there was only a statistical significant difference between osteopaths and manual therapists with respect to fatigue (P=0.010). Binary logistic regression analysis was performed to predict the probability of a patient experiencing side effects. The predictor variables were gender, age, smoking, medication and region of manipulation. Gender was the only statistically significant factor predicting the occurrence of all side effects after spinal manipulation (Table 1). Female patients were 1.84 times more likely to have side effects than male patients. When applying the same logistic regression to the five most common side effects, only headache could be Table 1 Logistic regression predicting side effects after spinal manipulation (n=465) Predictor

B

Wald w2

P-value

Odds ratio

95%CI

Gender

0.609

9.597

0.002

1.840

1.251–2.705

Definition of abbreviation: B: logistic regression coefficient.

predicted. The probability of headache after spinal manipulation was best explained by the following model, summarized in Table 2. A test of the model with the predictors (1) type of manipulation, (2) gender, (3) age and (4) medication versus a model with intercept only was statistically significant, w2=29.250, P=0.000. The model was able to classify 5.3% of those who would experience some side effects and 98.9% of those who would not, for an overall success rate of 79.2%. The odds ratio for the type of manipulation indicates that when holding all other variables constant, manipulation of the upper cervical spine is 3.17 times more likely to cause headache than manipulation of the lower cervical spine. For every 1 year increase in age, there is a 2.4% decrease in risk of headache. Female patients have 1.66 times more the risk on having headache than males. Patients who use medication regularly are 2.20 times more likely to get headache than people who do not.

4. Discussion 4.1. Number and type of reactions The number and type of side effects are in general comparable with previous studies. Senstad et al. (1996b) conducted a pilot study which formed the basis for two, more extensive investigations (Leboeuf-Yde et al., 1997; Senstad et al., 1997). The percentage of reactions observed in these trials, ranged from 34% to 55%. Local discomfort, headache, fatigue and discomfort outside the area of treatment were the most frequent complaints. In a study by Barrett and Breen (2000), 53% of the patients reported some sort of adverse reaction within 2 days of spinal manipulation that they attributed to the treatment. The number of reactions reported in our own study were slightly higher than in previous studies (Senstad et al., 1996b, 1997; Leboeuf-Yde et al., 1997). This difference can probably be attributed to the fact that, in our study, patients were only asked about side effects after the first visit. Senstad et al. (1996a) found that treatment reactions were most commonly reported after the first visit, diminishing gradually after the following

Table 2 Logistic regression predicting headache after spinal manipulation (n=465) Predictor

B

Wald w2

P-value

Odds ratio

95%CI

Type of manipulation LC versus UC NC versus UC Gender Age Medication

1.153 0.786 0.510 0.230 0.787

6.362 7.216 3.983 5.305 8.880

0.012 0.007 0.046 0.210 0.003

3.196 2.194 1.664 1.024 2.196

(1.293–7.766) (1.237–3.893) (1.009–2.745) (1.003–1.044) (1.309–3.685)

Definition of abbreviation: B: logistic regression coefficient; LC: lower cervical spine; UC: upper cervical spine; NC: non-cervical spine.


treatment sessions. One of their hypotheses is that many patients are fearful of spinal manipulation during the first visit. In addition, this study as well as the Barret and Breen (2000) study was carried out blind to the therapists. The higher incidences in both studies could be attributed to this blinding. 4.2. Onset, duration and severity of reactions No serious adverse effects were noted. It is however possible that some side effects may have persisted given that 19.37% still had reactions after 48 h. Unfortunately, there are no data available about how much longer these side effects continued. 4.3. Predictors of side effects Some patients are more likely to experience side effects than others and also the type of treatment determines whether side effects will occur. Women are more likely to report unpleasant reactions from spinal manipulation than men. This is in accordance with the findings of Senstad et al. (1996a). Whether these differences can be explained by some physiological phenomenon or whether women are more willing to report symptoms is not known. Headache, dizziness and nausea are significantly more likely to present after cervical manipulation than lumbar and thoracic treatment. The patient should be asked about these reactions at the next visit. Vautravers and Maigne (2000) claim that cervical manipulations should be contra-indicated for patients who experience dizziness, nausea or acute headache persisting for more than 2 days. Ignoring these red flags increases the likelihood of harming the patient. 4.4. Limitations of the study The present results must be viewed within the limitations of the study. The questionnaire asked only about side effects after the first visit. This may have resulted in over-reporting of reactions, because many patients may be fearful of spinal manipulation during their first treatment. When interpreting the results of a postal survey, one has to bear in mind that non-response can create a bias. In this survey there are two kinds of non-responders: practitioners and patients. Whereas the non-response rate of the practitioners (13.6%) is mainly due to the limited period of duration of this survey (4 months), the higher rate in patients (27.2%) could be attributed to several factors (not interested, forgotten, lost, y). In addition, it is possible that this group opted out because they did not experience any reactions and therefore disregarded the questionnaire. No demographic features of the patients could be obtained as these questions were

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not asked in the practitioners’ questionnaire. Since, according to the replies from the practitioners, there were no statistically significant differences in treatmentrelated variables between responders and non-responders, it can be considered that the non-response group had no or limited impact on the response bias. The data collected in the clinics may be positively biased. For practical reasons, we used consecutive sampling. However, it was not possible to verify whether the practitioners selected their patients in some other way that may have introduced a bias. Spinal manipulation was rarely the only treatment approach that was administered during the treatment session. It is therefore difficult for both the patient and the therapist to be certain whether side effects that arose were due to spinal manipulation. Side effects could have been due to other treatments during the session or to factors not covered in either questionnaire such as preexisting problems, lifestyle or environmental impacts, or concurrent treatment by other health professionals. The study model contained no control group. It is therefore not known whether some of the reported reactions are incidental or could have been a description of pre-existing symptoms. 4.5. Advantages of the study Despite the limitations of this study there are some advantages in comparison to previous studies. The patient and the therapist filled in their questionnaire separately. This was in contrast with previous studies, all data of which were collected by the treating therapist (Senstad et al., 1996a and b, 1997; Leboeuf-Yde et al. 1997). In these studies, patients may therefore have been reluctant to report negative reactions. The practitioner could misinterpret the information given or fail to record it correctly. In addition, the therapist could omit certain information on purpose. Patients were asked to report side effects within 48 h after treatment. In previous studies side effects had to be reported at the next visit, so the time interval could be widely spaced, which may have affected the accuracy of reporting. Previous studies made use of just one group of therapists (Senstad et al., 1996a and b, 1997; LeboeufYde et al., 1997; Barrett and Breen, 2000), namely chiropractors, whereas this study used a heterogeneous group of therapists who perform spinal manipulation.

5. Conclusion There is convincing evidence that spinal manipulation is associated with frequent minor adverse effects. The results of this study indicate that the common reactions can be predicted to some extent. Although it is difficult


B. Cagnie et al. / Manual Therapy 9 (2004) 151–156

to label side effects as a risk, it is important to differentiate patients who are susceptible to side effects in order to inform them correctly. Theoretically, it would be possible to reduce the frequency of complications after manipulation if the patient at risk could be identified and excluded from receiving manipulation. In clinical practice, it is important to differentiate between ‘normal’ and ‘abnormal’ side effects because the latter may indicate a need to reconsider diagnosis or therapy. Abnormal reactions, such as dizziness, nausea, etc. should alert the practitioner as precursors of more sinister treatment reactions.

Acknowledgements The authors would like to thank Ms. Veerle De Loose, Ms. Sofie Demets, Mr. Diederik Fontaine and Mr. Robin Hellebuyck for their assistance in collecting the data.

References Assendelft W, Bouter L, Knipschild P. Complications of spinal manipulation. The Journal of Family Practice 1996;42(5):475–80. Barrett AJ, Breen AC. The adverse effects of spinal manipulation. Journal of Royal Society of Medicine 2000;93(5):258–9. Di Fabio RP. Manipulation of the cervical spine: risks and benefits. Physical Therapy 1999;79:50–65. Ernst E. Prospective investigations into the safety of spinal manipulation. Journal of Pain Symptom Management 2001;21(3):238–42. Haldeman S, Rubinstein S. Cauda equina syndrome in patients undergoing manipulation of the lumbar spine. Spine 1992;17: 1469–73.

Haldeman S, Kohlbeck F, Mc Gregor M. Risk factors and precipitating neck movements causing vertebrobasilar artery dissection after cervical trauma and spinal manipulation. Spine 1999;24(8):785–94. Haldeman S, Kohlbeck F, Mc Gregor M. Unpredictability of cerebrovascular ischemia associated with cervical spine manipulation therapy. A review of sixty-four cases after cervical spine manipulation. Spine 2002;27(1):49–55. Hurwitz EL, Aker PD, Adams AH, Meeker WC, Shekelle PG. Manipulation and mobilization of the cervical spine. A systematic review of the literature. Spine 1996;21:1746–59. Klougart N, Leboeuf-Yde C, Rasmussen LR. Safety in chiropractic practice, part I: the occurrence of cerebrovascular accidents after manipulation to the neck in Denmark from 1978–1988. Journal of Manipulative and Physiological Therapeutics 1996;19:371–7. Leboeuf-Yde C, Hennius B, Rudberg E, Leufvenmark P, Thunman M. Side effects of chiropractic treatment: a prospective study. Journal of Manipulative and Physiological Therapeutics 1997;20(8): 511–5. Pattijn J. Complications in manual medicine: a review of the literature. Journal of Manual Medicine 1991;6:89–92. Powell FC, Hanigan WC, Olivero WC. A risk/benefit analysis of spinal manipulation therapy for relief of lumbar or cervical pain. Neurosurgery 1993;33:73–8. Rivett D, Milburn P. A prospective study of complications of cervical spine manipulation. Journal of Manual and Manipulative Therapy 1996;4:166–70. Senstad O, Leboeuf-Yde C, Borchgrevnink C. Predictors of side effects to spinal manipulative therapy. Journal of Manipulative and Physiological Therapeutics 1996a;19(7):441–5. Senstad O, Leboeuf-Yde C, Borchgrevnink C. Side effects of chiropractic spinal manipulation: types, frequency, discomfort and course. Scandinavian Journal of Primary Health Care 1996b;14:50–3. Senstad O, Leboeuf-Yde C, Borchgrevnink C. Frequency and characteristics of side effects of spinal manipulative therapy. Spine 1997;22(4):435–41. Vautravers P, Maigne JY. Cervical spine manipulation and the precautionary principle. Joint Bone Spine 2000;67:272–6.

ARTICLE IN PRESS



Original article

Impaired trunk muscle function in sub-acute neck pain: etiologic in the subsequent development of low back pain? G. Lorimer Moseleya,b,* b

a Division of Physiotherapy, The University of Queensland, Australia Department of Physiotherapy, Royal Brisbane & Women’s Hospital, Brisbane, Herston 4029, Australia

Received 3 January 2003; received in revised form 29 January 2004; accepted 4 March 2004

Abstract Low back pain (LBP) and neck pain are associated with dysfunction of the trunk and neck muscles, respectively, and may involve common or similar mechanisms. In both cases, dysfunction may compromise spinal control. Anecdotally, neck pain patients commonly develop LBP. This study investigated the possibility that trunk muscle function is compromised in neck pain patients and that compromised trunk muscle function is associated with increased risk of LBP. Fifty-four neck pain patients and 52 controls were assessed on an abdominal drawing-in task (ADIT) and on self-report tests. Performance on the ADIT was able to detect neck pain patients with 85% sensitivity and 73% specificity. Catastrophizing and McGill pain questionnaire (affective) scores were higher in patients with an abnormal task response than in patients with an uncertain or normal response, although the self-report data did not predict task performance. Fifty subjects from each group were contactable by telephone at 2 years. They were asked whether they had experienced persistent or recurrent LBP since the assessment. Subjects (patients and controls) who obtained an abnormal response on the ADIT were 3 to 6 times more likely to develop persistent or recurrent LBP than those who obtained an uncertain or normal response. ADIT performance was the main predictor of development of LBP in patients. The results suggest that reduced voluntary trunk muscle control in neck pain patients is associated with an increased risk of developing LBP. r 2004 Elsevier Ltd. All rights reserved.

1. Introduction Postural activation of the deepest abdominal muscle, transverses abdominis (TrA), is altered in people with chronic recurrent low back pain (LBP) (Hodges and Richardson, 1996) and in healthy subjects given experimentally induced acute LBP (Hodges, 1999; Moseley et al., 2003). Those findings suggest that LBP may cause TrA dysfunction. The converse, that TrA dysfunction causes LBP, may also be true; extensive data now exist that show that TrA makes an important contribution to stiffness between vertebral segments (Hodges et al., 2001) and that postural activity of this muscle is consistent with such a contribution (Hodges and Richardson, 1999). Furthermore, normal control of TrA is lost in people with chronic recurrent LBP, even when they are pain free at the time (Hodges, 2001). *Department of Physiotherapy, Royal Brisbane & Women’s Hospital, Brisbane, Herston 4029, Australia. Tel.: +61-7-36362590; fax: +61-7-36362595. E-mail address: [email protected] (G.L. Moseley). 1356-689X/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2004.03.002

TrA activity is decreased and/or delayed during acute experimentally induced LBP and this is accompanied by an increase and/or augmentation of at least one superficial abdominal muscle (Hodges et al., 2003; Moseley et al., 2003). This pattern of activity suggests that, during spinal pain, the central nervous system (CNS) effectively splints the trunk to limit amplitude and velocity of movement. This would be consistent with the pain-adaptation model (Lund et al., 1991), which proposes that the motor response to pain depends on the task at hand, such that the agonist and antagonist are inhibited and facilitated, respectively. Although general spinal splinting may be beneficial in the short term, there may be an associated cost. For instance, splinting reduces spinal flexibility, which is probably important for normal function and dampening of reactive forces (Hodges et al., 1999). Splinting may also result in increased loading of the spine and stimulation of nociceptors in spinal structures (Gardner-Morse and Stokes, 1998) and these mechanisms may be etiologic in recurrence and/or chronicity.


G.L. Moseley / Manual Therapy 9 (2004) 157–163

One clinical area to which these findings are relevant is that of chronic neck pain. Recent findings that suggest similar mechanisms may underlie neck muscle dysfunction in neck pain and trunk muscle dysfunction in LBP (Jull et al., 1999; Sterling et al., 2001) raise the possibility that there may be a common effect. Perhaps spinal pain imparts similar effects regardless of the level of the spine at which the pain is experienced. If so, trunk muscle dysfunction associated with neck pain may be etiologic in the development of LBP. Alternatively and in contrast, perhaps a generic problem in the motor system leads to symptoms in the neck and low back. Anecdotally, insidious onset of LBP is common in people with chronic neck pain. Assessment of postural control of TrA requires intramuscular electromyography (EMG), which is costly and invasive. An alternative method, albeit less accurate, is assessment of voluntary drawing-in of the lower abdominal wall. This method, the so-called abdominal drawing-in task (ADIT), is an established clinical assessment tool. Performance on the task has been linked to postural activity during limb movements using intramuscular EMG and is able to effectively discriminate people according to whether or not they have LBP (Hodges et al., 1996). The current work aimed to test two hypotheses. First, that people with sub-acute neck pain perform badly on the ADIT and second, that reduced performance on the ADIT is associated with increased risk of LBP in the following 2 years.

2. Methods

Fig. 1. Subject recruitment and experimental plan.

subjects were excluded. Informed consent was obtained and all procedures were approved by the institutional ethics committee and conformed with the Declaration of Helskinki.

2.1. Subjects 2.2. Experimental procedure Seventy-eight patients and 57 age-matched controls, mean7SD age, height and weight 3076 years, 173714 cm and 7477 kg, respectively, participated in the study. Subject recruitment and experimental plan is shown in Fig. 1. Volunteer patients were drawn from those who presented for physiotherapy for neck pain of more than 4 months and not more than 1 year duration, with or without radiating shoulder and/or arm pain. Subjects were excluded if they had experienced LBP within the last 2 years, had participated in a trunk muscle training program other than their normal gymnasium or fitness work, had undergone abdominal or spinal surgery in the last 2 years, or were referred for medical opinion and/or pain management. Twenty-two subjects were excluded. Volunteer control participants were obtained via advertisements on notice boards and direct approach. Control participants were excluded from the study if they reported chronic pain, current neck pain, a history of neck pain in the last 4 years, or met any of the other exclusion criteria listed above. Five

ADIT: prior to testing, each subject was instructed in the performance of the ADIT in four-point kneeling, according to the guidelines recommended by Richardson et al. (1999). Any substitution strategies that were identified were corrected. Seven subjects were unable to adopt this position, so an adjustable support was placed under their forehead. It is not known whether this may have affected their performance. The testing procedure was the same as that described by Hodges et al. (1996). The subject lay prone, with an air filled non-elastic pressure bag placed under the lower abdomen. The pressure bag was connected to a sphygmamanometer gauge (Stabilizer, Chattanoogas) and the test score was assessed as the change in pressure when the subject attempted the ADIT. The investigator was blind to the category of the subject and strictly followed the testing process. Prior to the subject entering the room, the pressure bag was placed deflated in the middle of a treatment plinth, and a small pillow was

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placed at the foot of the plinth. The subject was given the following instruction; ‘‘Lie face down on the bed, with the blue bag underneath the lower portion of your abdomen, your legs straight and your shins on the pillow, and your head resting comfortably in the hole. Please ensure that your head and neck are comfortable’’. The position of the bag was adjusted if necessary, and then the bag was pumped to a pressure of 70 mmHg. The subject was then given the following instruction ‘‘Slowly draw your abdomen off the pressure bag, hold it for 5 s and then slowly relax’’. The subject was given 4 practice trials, and then allowed to rest for 30 s. The pressure was then readjusted to 70 mmHg, and the task was performed again, this time for 10 s. The maximum pressure change sustained for more than 2 s was converted to a rating based on Hodges et al. (1996) in which X4 mmHg was considered a normal response, 2–4 mmHg uncertain, and o4 mmHg an abnormal response. This testing strategy is reliable (intratester ICC (95% CI)=0.91 (0.71–0.99)) (Moseley, 2001).

2.3. Self-report data The neck disability index (NDI) (Vernon and Mior, 1991) is a 10-item self-report questionnaire, which assesses to what extent the patient feels they are affected in daily activities by their neck pain. NDI has satisfactory internal validity and reliability (Vernon and Mior, 1991). The McGill pain questionnaire (MPQ) (Melzack, 1975) is a widely used clinical tool, has high validity and is sufficiently sensitive to change in the majority of pain populations (Melzack, 1975). The subfactors of the MPQ provide information about the sensory, affective, evaluative and miscellaneous aspects of pain, and a rating of present pain intensity. The pain catastrophizing scale (PCS) (Sullivan et al., 1995) is a self-report questionnaire that assesses catastrophic thinking about pain and injury. Thirteen statements such as ‘‘I feel I can’t go on’’ are rated according to the degree to which the subject has that particular thought or feeling when they are experiencing pain. The PCS has strong construct validity and is a reliable and stable measurement tool (Sullivan et al., 1995).

2.4. Treatment delivered Neck pain patients were treated at the discretion of the treating physiotherapist. No limits were placed on the type, frequency or duration of treatment. Informal assessment indicated that treatment would typically involve manual therapy and electrophysical modalities.

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2.5. Two-year telephone follow-up Participants were contacted via telephone B2 years after the initial assessment. Patients were asked ‘‘Do you still have neck pain?’’ Pilot studies showed that this item was likely to detect those patients for whom their neck pain had not completely resolved, even if they were pain-free at the time of testing (GL Moseley, Unpublished data). Patients and controls were asked ‘‘Have you experienced recurrent (more than 4 episodes) or persistent LBP in the last 2 years?’’ 2.6. Statistical analysis The following statistical analyses were performed in Statistica 5.1 (Statsofts Tulsa, USA): (i) A one-way MANOVA was used to compare the unconverted pressure change score on the ADIT and the self-report data (MPQ, sensory, affective, evaluative, miscellaneous, present pain intensity, subfactors of the MPQ, PCS; dependent variables, DV) between patients and controls (independent variable, IV). (ii) A one-way MANOVA was used to compare the MPQ, the subfactors of the MPQ and the PCS (DV) according to categorized ADIT score (IV). (iii) A logistic regression analysis was used to investigate the relationship between ADIT category (DV) and the self-report data (IV). (iv) A separate logistic regression analysis was used to determine, the relationship between the presence of chronic or recurrent LBP at 2 years (DV) and the ADIT category and self-report data (IV). (v) Fisher’s exact tests were used to determine if there was an increased likelihood of developing LBP if subjects had an abnormal ADIT score. Thus, five separate statistical tests were conducted, which elevated the probability of a type I error. A Bonferroni correction would elevate the probability of a type II error and set a=B0.01, which was considered to be too conservative. Because the current work was exploratory in nature, and in light of criticism in the literature of Bonferroni and other corrections, e.g. Perneger (1998), it was considered appropriate to maintain a=0.05.

3. Results Subject characteristics are presented in Table 1. There were no differences between groups in demographic details. The mean score on the ADIT was lower for patients than for controls (1.8 mmHg71.5 mmHg and 5.3 mmHg71.8 mmHg for the patients and controls, respectively, Po0.01). Based on categorized ADIT data, 75% of patients (40/54) and 15% of controls (8/52) obtained an abnormal response and 15% of patients


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(8/54) and 53% of controls (28/52) obtained a normal response (Fig. 2A). Thus, performance on the ADIT was able to detect the patients with 83% specificity and 75% sensitivity. PCS and MPQa were higher in the abnormal ADIT group than the other two groups (Po0.04 for both), but there were no other differences in self-report data between groups (Fig. 2B). The logistic regression with the ADIT category as the dependent

Table 1 Demographic and self-report data for patients and control subjects

Age (yr) Height Weight Female Working full-time Working part-time Neck disability index McGill pain questionnaire Total Sensory Affective Evaluative Miscellaneous Present pain intensity Duration of neck pain (months) Currently receiving compensation Non-English speaking background

Neck pain patients (n ¼ 54)

Control subjects (n ¼ 52)

3377 172710 cm 7575 kg 59% 46% 34% 3577

3077 17078 cm 7076 cm 64% 100% 0% —

32.678.0 12.176.3 8.074.0 4.171.3 8.374.1 3.571.0 773

— — — — — — —

47%

0%

9%

18%

variable and the self-report data as independent variables revealed no relationship (P ¼ 0:83). Fifty subjects in each group (93% and 96% for patients and controls, respectively) were contactable at 2 years. The sub-factors of the MPQ were removed from the logistic regression as they demonstrated multicolinearity with the MPQ total score (tolerance o0.05 for all). ADIT category and self-report data were predictive of LBP at 2 years (P ¼ 0:02) (Table 2). Eighty per cent (40/50) of patients indicated that they still had neck pain at 2 years. Seventy-four per cent (23/ 31) of patients who obtained an abnormal response on the ADIT reported persistent or recurrent LBP at 2 years, which was B3 times that for the uncertain (25% 3/12) and normal (14% 1/7) response groups, respectively (Po0.03 for both). Of the control subjects who had an abnormal response on the ADIT, (75% 6/8) went on to develop persistent or recurrent LBP in the following 2 years, which was B6 times that for the

Table 2 Summary of the logistic regression for patients, with low back pain at 2 years as the dependent variable and pain catastrophizing scale (PCS), McGill pain questionnaire total score (MPQT), neck disability index (NDI) and ADIT category as independent variables Final loss: 31.608; w2 (4)=11.569; P ¼ 0:020 Const.B0 PCS MPQT Estimate Odds ratio (unit ch) Odds ratio (range)

1.090 0.336

0.126 1.1342 119.761

0.077 0.926 0.0228

NDI

ADIT

0.006 1.006 1.128

0.562 1.755 29.262

Fig. 2. (A) Distribution of normal, uncertain and abnormal scores on the ADIT. Shaded column denotes patients and open column denotes control subjects. (B) Self report data according to ADIT performance for neck disability index (NDI), Pain catastrophizing scale (PCS), and the subscales of the McGill pain questionnaire (MPQ); sensory, affective, evaluative, miscellaneous and total (left y-axis), and the present pain intensity (PPI) (right yaxis). Mean and SD are shown. Note higher PCS and MPQa scores in the abnormal response groups (asterix denotes Scheffe Po0.04).


Fig. 3. Percentage of sample with persistent or recurrent (more than 4 episodes) LBP over the following 2 years grouped according to ADIT performance for patients (filled columns) and controls (open columns). Note greater likelihood of LBP in those with an abnormal response for patients and controls (asterix denotes Fisher’s exact Po0.04).

uncertain (14% 2/14) and normal response 11% (3/28) groups (Po0.04 for both) (Fig. 3).

4. Discussion The first main finding of the current work is that people with sub-acute neck pain have a reduced capacity to perform the ADIT. This is supported by a lower mean score for the ADIT in patients than the controls and a higher proportion of abnormal responses in the patient group than in the control group. The second main finding is that reduced performance is associated with increased risk of LBP over the following 2 years, for both patients and controls. This is supported by a significant relationship between ADIT category and LBP at 2 years and a greater likelihood of LBP in participants (both patients and controls) who obtained an abnormal response on the ADIT than those who obtained an uncertain or normal response. The pressure change values for the ADIT in the present work, for patients and controls, are similar to results from previous studies in subjects with and without chronic recurrent LBP (Hodges et al., 1996). The current work supports the finding from that study that converting the pressure change score to a rating improves the utility of the test: in the current study the rating had 83% specificity and 75% sensitivity in detecting neck pain patients. These results suggest that performance at this task may be reduced in a similar fashion in both neck pain patients and LBP patients. This is an intriguing finding. It suggests that there may

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be effects on trunk muscle function that are consistent between neck pain and LBP and therefore raises the possibility that neck muscle function may be compromised in LBP patients. These issues could be clarified with further research. The current work suggests that the anatomical specificity of pain is not critical in determining its impact on muscle control. This is not consistent with recent work by our group that showed a clear effect of impending LBP but not impending elbow pain on trunk muscle control (Moseley et al., 2002b). However, this discrepancy may be explained by the biomechanical demands of the response to the stimuli involved. That is, because the changes in trunk muscle function associated with pain probably reflect an alternative postural strategy (Moseley and Hodges, 2004), a similar effect may be observed during neck pain because the biomechanical demands associated with neck pain are sufficiently similar to those associated with LBP, whereas those associated with elbow pain are not. The present work casts new light on the mechanisms that underlie development of LBP in patients with neck pain. However, several questions remain unanswered. For example, is trunk muscle dysfunction present prior to neck pain and, in which case, is trunk muscle dysfunction a risk factor for neck pain? Also, is trunk muscle dysfunction an etiological mechanism, for instance via reduced intersegmental control during functional movements as has been proposed (Hodges, 1999), or is it a benign epiphenomenon of some other mechanism? These questions are currently being investigated by our group. The results also have implications for understanding the development of LBP in the otherwise asymptomatic population: 75% of control subjects who had an abnormal ADIT score went on to experience LBP. Although a link between altered function of the deep trunk muscles and the development of back trouble is clinically well accepted, the present findings provide the first prospective evidence for such a link, at least between performance of this voluntary task, thought to target the deepest abdominal muscle, TrA, and development of LBP. Notably, the current study did not evaluate pain-related beliefs and attitudes in the control subjects, which may also have been predictive. Further research is required to explore these issues in otherwise asymptomatic subjects. It is not known why some chronic neck pain patients demonstrate trunk muscle dysfunction and others do not. This question has been asked previously within the context of neck muscle dysfunction in chronic neck pain by evaluating trapezius muscle activity at rest and during isometric and dynamic tasks (Nederhand et al., 2001, 2002, 2003). Those studies revealed increased activity in the upper trapezius on the contralateral side and decreased activity on the ipsilateral side to the task and changes were independent of the nature of onset but


G.L. Moseley / Manual Therapy 9 (2004) 157–163

dependent on the degree of disability. While the current study found no difference in disability between those who could and couldn’t perform the ADIT, it did find higher PCS and MPQa scores in those with an abnormal response on initial assessment. That finding raises the possibility that catastrophic thought processes about pain, or an elevated affective/emotional impact of pain, has a particular impact on performance of the task. In light of those data, it is notable that the psychosocial measures used here did not contribute to the development of LBP at 2 years (P>0.07 for all). Importantly, psychosocial factors have been implicated in chronic pain (Vlaeyen et al., 1995; Sullivan et al., 1998; Turner et al., 2000) and fear of pain and (re)injury has been shown to impact on trunk muscle function during trunk movements (Watson et al., 1997; Vlaeyen et al., 1999) and on postural trunk muscle activity during limb movements (Moseley et al., 2002a). It is possible that the current work was underpowered to detect an effect of psychosocial factors on the development of LBP in this group. Alternatively, the current results may reflect a distinct mechanism underlying recurrence or the development of pain at a secondary anatomical site. Further investigation using a wider battery of tests may be indicated. The present results should be interpreted in light of several issues. First, although subjects were excluded if they had experienced LBP in the previous 2 years, episodes of LBP prior to that were not evaluated. This criterion was based on findings from Hides et al. (2001), which showed 84% recurrence inside 1 year. However, the exclusion criteria did not remove the possible confounder that performance at the ADIT is associated with the frequency and/or severity of LBP more than 2 years previously. Second, the ADIT is effectively a behavioural test, which requires voluntary effort. People who experience chronic pain are often limited by poor motivation during the performance of voluntary tasks (Luoto et al., 1996). The possibility that this may have undermined the results cannot be excluded, however it is probably unlikely to fully explain them. Importantly reduced motivation on the part of patients would not corrupt the second finding that performance on the ADIT was related to development of LBP, it would just imply that a different task would yield the same result. Third, the items used for telephone follow-up at 2 years may have been limited in their sensitivity to delineate between those with and without LBP. That is, participants may have difficulty in recalling experiences over such a long period. That said, the effect of this limitation would be to falsely categorize those with LBP in the noLBP group, which would weaken the sensitivity of the protocol. Thus, this limitation does not threaten the main finding of the study. The follow-up question concerning neck pain may also be misleading. Although pilot work suggested that the question used was sensitive

to detect those for whom neck pain had not completely resolved, it provides little information about the resolution of the particular episode for which the patient sought attention. This limitation may have underpinned the large proportion of patients (80%) who answered that question to the affirmative. Finally, the ADIT does not assess muscle activity during functional tasks. Although a link has been demonstrated between ADIT rating and postural activity of TrA during limb movements (Hodges et al., 1996), it is possible that people with chronic neck pain demonstrate normal motor control on functional tasks even though they perform badly on the ADIT. Although several questions remain unanswered, it seems reasonable to suggest that on the basis of the current results, maintenance of normal trunk muscle control should be a goal of therapy in patients with subacute neck pain. This preventative strategy may limit the incidence of persistent or recurrent LBP in neck pain patients. A clinical trial would verify this possibility.

5. Conclusion The current study showed that people with sub-acute neck pain have a reduced capacity to perform the ADIT, and that reduced ADIT performance is associated with increased risk of LBP over the following 2 years. These findings suggest (i) that spinal pain impacts on trunk muscle control regardless of the spinal level at which pain is experienced, (ii) that altered trunk muscle function associated with neck pain may be etiologic in the subsequent development of LBP, and (iii) that altered trunk muscle function in otherwise asymptomatic people may also be etiologic in the subsequent development of LBP. The results imply that maintenance of normal voluntary trunk muscle function may be important in preventing LBP in patients with subacute neck pain. Further research is required to evaluate the mechanism and meaning of altered trunk muscle function in neck pain and LBP and to optimize prevention and management strategies.

Acknowledgements Lorimer Moseley is supported by grant number 210348 from the National Health and Medical Research Council of Australia.

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ARTICLE IN PRESS G.L. Moseley / Manual Therapy 9 (2004) 157–163 Hides JA, Jull GA, Richardson CA. Long-term effects of specific stabilizing exercises for first-episode low back pain. Spine 2001;26(11):E243. Hodges PW. Is there a role for transversus abdominis in lumbo-pelvic stability? Manual Therapy 1999;4(2):74–86. Hodges PW. Changes in motor planning of feedforward postural responses of the trunk muscles in low back pain. Experimental Brain Research 2001;141(2):261–6. Hodges PW, Cresswell A, Thorstensson A. Preparatory trunk motion accompanies rapid upper limb movement. Experimental Brain Research 1999;124(1):69–79. Hodges PW, Cresswell AG, Daggfeldt K, Thorstensson A. In vivo measurement of the effect of intra-abdominal pressure on the human spine. Journal of Biomechanics 2001;34(3):347–53. Hodges PW, Moseley GL, Gabrielsson A, Gandevia SC. Experimental muscle pain changes feedforward postural responses of the trunk muscles. Experimental Brain Research 2003;151:262–71. Hodges PW, Richardson C, Jull G. Evaluation of the relationship between laboratory and clinical tests of transversus abdominis function. Physiotherapy Research International 1996;1(1):30–40. Hodges PW, Richardson CA. Inefficient muscular stabilization of the lumbar spine associated with low back pain. A motor control evaluation of transversus abdominis. Spine 1996;21(22): 2640–50. Hodges PW, Richardson CA. Transversus abdominis and the superficial abdominal muscles are controlled independently in a postural task. Neuroscience Letters 1999;265:91–4. Jull G, Barrett C, Magee R, Ho P. Further clinical clarification of the muscle dysfunction in cervical headache. Cephalalgia 1999;19(3):179–85. Lund JP, Donga R, Widmer CG, Stohler CS. The pain-adaptation model: a discussion of the relationship between chronic musculoskeletal pain and motor activity. Canadian Journal of Physiological Pharmacology 1991;69(5):683–94. Luoto S, Hupli M, Alaranta H, Hurri H. Isokinetic performance capacity of trunk muscles. Part II: Coefficient of variation in isokinetic measurement in maximal effort and in submaximal effort. Scandinavian Journal of Rehabilitation Medicine 1996;28(4):207–10. Melzack R. The McGill pain questionnaire: major properties and scoring methods. Pain 1975;1(3):277–99. Moseley G, Hodges P, Nicholas M. Fear of low back pain delays postural activation of transversus abdominis in healthy subjects. In: Proceedings of the Seventh International Physiotherapy Congress, Sydney, Australia, 2002a. Moseley G, Hodges P, Nicholas M. Fear of pain disrupts postural control of the back muscles, but it depends on the anatomical relevance of the impending pain. In: Proceedings of the 10th World Congress on Pain. San Diego, USA: IASP Press; 2002b. Moseley GL. Clinical and physiological investigation of the psychophysiology of pain and movement. Doctoral thesis,

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Faculty of Medicine. The University of Sydney, Sydney, 2001. p. 446. Moseley GL, Hodges PW. Are the changes in postural control associated with low back pain caused by pain interference? Clinical Journal of Pain 2004, in press. Moseley GL, Nicholas MK, Hodges PW. Pain differs from nonpainful attention-demanding or stressful tasks in its effect on postural control patterns of trunk muscles. Experimental Brain Research 2003, in press. Nederhand MJ, Ijzerman MJ, Hermens HJ, Baten CTM, Zilvold G. Cervical muscle dysfunction in the chronic whiplash associated disorder grade ii (wad-ii). Spine 2000;25(15):1938–43. Nederhand MJ, Hermens HJ, Ijzerman MJ, Turk DC, Zilvold G. Cervical muscle dysfunction in chronic whiplash-associated disorder grade 2—the relevance of the trauma. Spine 2002;27(10):1056–61. Nederhand MJ, Hermens HJ, Ijzerman MJ, Turk DC, Zilvold G. Chronic neck pain disability due to an acute whiplash injury. Pain 2003;102(1–2):63–71. Perneger TV. What’s wrong with bonferroni adjustments. British Medical Journal 1998;316(7139):1236–8. Richardson C, Jull G, Hodges P, Hides J. Therapeutic exercise for spinal segmental stabilization in low back pain. London: Churchill Livingstone; 1999. Sterling M, Jull G, Wright A. The effect of musculoskeletal pain on motor activity and control. Journal of Pain 2001;2:135–45. Sullivan MJ, Stanish W, Waite H, Sullivan M, Tripp DA. Catastrophizing, pain, and disability in patients with soft-tissue injuries. Pain 1998;77(3):253–60. Sullivan MJL, Bishop SR, Pivik J. The pain catastrophizing scale: development and validation. Psychological Assessments 1995;7(4):524–32. Turner JA, Jensen MP, Romano JM. Do beliefs, coping, and catastrophizing independently predict functioning in patients with chronic pain? Pain 2000;85(1–2):115–25. Vernon H, Mior S. The neck disability index: a study of reliability and validity. Journal of Manipulative and Physiological Therapeutics 1991;14(7):409–15. Vlaeyen JW, Haazen IW, Schuerman JA, Kole-Snijders AM, van Eek H. Behavioural rehabilitation of chronic low back pain: comparison of an operant treatment, an operant-cognitive treatment and an operant respondent treatment. British Journal of Clinical Psychology 1995;34(1). Vlaeyen JW, Seelen HA, Peters M, de Jong P, Aretz E, Beisiegel E, Weber WE. Fear of movement/(re)injury and muscular reactivity in chronic low back pain patients: an experimental investigation. Pain 1999;82(3):297–304. Watson PJ, Booker CK, Main CJ. Evidence for the role of psychological factors in abnormal paraspinal activity in patients with chronic low back pain. Journal of Musculoskeletal Pain 1997;5(4):41–56.

ARTICLE IN PRESS



Original article

A survey on the importance of lumbar coupling biomechanics in physiotherapy practice Chad Cooka,*, Christopher Showalterb a

Department of Rehabilitation Sciences, Texas Tech University Health Sciences Centre, Odessa, 800 West Fourth Street, Odessa, TX 79763, USA b Maitland Australian Physiotherapy Seminars, P.O. Box 1244, Cutchogue, NY 11935, USA Received 30 June 2003; received in revised form 29 January 2004; accepted 4 March 2004

Abstract Knowledge of lumbar coupling biomechanics is foundational in many manual therapy disciplines. 3-D studies of lumbar coupling indicate that coupling direction may not be predictable. The purpose of this study was to investigate physiotherapists’ perception of importance of lumbar coupling for validation of manual therapy, necessity in treatment, and perceived direction of lumbar coupling biomechanics. A sample of 369 physiotherapists within the United States volunteered to participate in this study. An ologit regression analysis investigated factors associated with perception of lumbar coupling. A Fleiss Kappa determined the agreement of coupling direction among physiotherapists. The majority of physiotherapists indicated that lumbar coupling biomechanics were important or very important, frequently used during treatment, and necessary for validation of manual therapy. The ologit regressions identified that the importance placed upon lumbar coupling biomechanics is highly related toward therapists’ preconcept of coupling. Kappa values for the five spinal segments were negative indicating worse than chance agreement: L122 ¼ 0:10; L223 ¼ 0:11; L324 ¼ 0:09; L425 ¼ 0:10; and L52S1 ¼ 0:09: The poor Kappa values, strong pre-conceptual perceptions of coupling necessity, and the importance placed upon lumbar coupling for treatment could lead to disparities among physiotherapists in lumbar manual therapy assessment and treatment. r 2004 Elsevier Ltd. All rights reserved.

1. Introduction Biomechanical analysis, including investigation of coupled motion is often identified as essential in the assessment and treatment of low back pain (Cassidy, 1976; Grice, 1979; Pearcy et al., 1985; Gomez, 1994; Panjabi et al., 1994; Mellin et al., 1995; Winkel et al., 1996). There are two principle components of lumbar coupling; quantity of motion, used in detection of hypo and hypermobility and direction of coupling behaviour. It has been suggested that the link between pathology of the lumbar spine may be best represented by addressing the pattern or direction of coupling behaviour (Fryette, 1954; Faye, 1984; Gertzbein et al., 1986; Plaugher, 1993; Gracovetsky et al., 1995; Winkel et al., 1996; Lund et al., 2002). Others have suggested that the quantity of lumbar coupling behaviour is beneficial in assessment and treatment (Pearcy et al., 1985; Panjabi et al., 1994; *Corresponding author. Tel.: +1-915-335-5370; fax: +1-915-3355365. E-mail address: [email protected] (C. Cook). 1356-689X/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2004.03.003

Harrison et al., 1998). The most controversial of the two assessment methods is the theory of directional lumbar coupling, a theory based on the invalidated premise that a ‘‘normal’’ lumbar coupling pattern exists in nonpathological individuals (Panjabi et al., 1994; Harrison et al., 1998; Gibbons and Tehan, 2001). Many manual therapy disciplines base specific mobilization, manipulation, and muscle energy techniques on selected theories of lumbar coupling direction (Stoddard, 1972; Beal, 1989; Hartman, 1997). Often, a specific technique requires pre-positioning of for spinal segment apposition or movement into a desired coupling direction. During apposition, the clinician will generally side-bend, adjust the sagittal plane position of the spine, and then rotate to lock the level above or below the targeted segment. These theories are inconsistently reported, lack empirical validation, and are generally defined through ‘‘expert-based’’ learning models (Harrison et al., 1998; Cook, 2003). The feasibility exists, that if practicing therapists do not share consistent directional coupling pattern expectations, the results of their assessment and treatment may be dissimilar.

ARTICLE IN PRESS C. Cook, C. Showalter / Manual Therapy 9 (2004) 164–172

1.1. Coupling definition Coupled motion is the rotation or translation of a vertebral body about or along one axis that is consistently associated with the main rotation or translation about another axis (Panjabi et al., 1992). During movement, translation occurs when movement is such that all particles within that segment move in the same direction with the same velocity (Panjabi et al., 1992). With movement, rotation occurs as a spinning or angular displacement of the vertebral body around some axis. Biomechanical coupling is three-dimensional (3-D) and takes place within six degrees of freedom. The six degrees of freedom can translate along and rotate about each orthogonal axis (Panjabi et al., 1992). The 3-D motions in humans correspond to flexion/extension, rotation, and side bending forces; one specific movement initiation (such as side bending) theoretically activates movement in the other five component motions. The behaviour of the coupled pattern is dependent on the first motion of initiation (e.g., side bending), the posture of the spine, and the pathology of the segment (Panjabi et al., 1989). 1.2. Coupling measurement and findings The foundational works on coupling mechanics used observation or controversial two-dimensional (2-D) radiographic imagery (Harrison et al., 1998). Past 2-D studies involved cadaveric tissue, X-rays of live subjects, or single X-rays of segments, and used a small sample of subjects (Evans and Lissner, 1959; Harrison et al., 1998). Prior to 1969, only 2-D studies were executed for spinal coupling, signifying that any study performed prior to 1969 encompassed these errant methods (Harrison et al., 1998). 2-D imagery leads to magnification errors, projection of translations as rotations, rotations as translations, and misleading results (Panjabi et al., 1994; Harrison et al., 1996, 1998). The most frequently used method of 2-D imagery involves lateral stress radiograms, a notoriously unreliable method of analysis that is still commonly used today (Nelson, 1993; Harrison et al., 1999). Basing the coupling pattern on observation and potentially flawed 2-D radiographic methods, may be one of the reasons such poor continuity existed among

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past researchers. Table 1 outlines early 2-D lumbar coupling theories. Contemporary studies have used three-dimensional (3-D) assessment, which more accurately measures the six degrees of freedom associated with coupling motion (Olin et al., 1976; Rab and Chao, 1977; Stokes et al., 1980). The majority of 3-D coupling studies have investigated coupled lumbar behaviour with side bending initiation while in a neutral postural position (Schultz et al., 1979; Pearcy and Tibrewal, 1984; McGlashen et al., 1987; Panjabi et al., 1989; Vincenzino and Twomey, 1993; Panjabi et al., 1994; Cholewicki et al., 1996). Most studies found that coupling direction was dependent upon the level of the spine more so than whether the segment was from a live or cadaveric specimen (Panjabi et al., 1994). Findings of studies investigating side bending initiated coupled motion in neutral, extension, and flexion also display variability and are presented in Table 2. 1.3. Purpose of the study There were two purposes to this study. Firstly, we planned to investigate which variables are associated with the coupling importance in determination of use, validation, and frequency of use during practice. Secondly, to investigate therapists’ perception of directional coupling biomechanics of the lumbar spine in a non-pathological individual which would identify if clinicians agree on a predetermined coupling direction. The literature is inconsistent in identifying a common lumbar coupling pattern, therefore it was feasible that disparity existed among practicing clinicians. If disparity was found to exist in directional coupling knowledge, and if there was a suggested necessity of lumbar coupling knowledge by many manual therapists, the occurrence of variable assessment and treatment continuity among clinicians was thought to be likely.

2. Materials and methods 2.1. Sample Three hundred and sixty-nine physiotherapists participated in this study. The demographic information

Table 1 Coupled lumbar motion with side bending initiation (neutral spine). Classic observation or 2-D studies Author

L1–2

L2–3

L3–4

L4–5

L5–S1

Lovett (1905) Fryette (1954) Stoddard (1959) Kapandji (1974) Rolander (1966)

Same Opposite Opposite Opposite None






C. Cook, C. Showalter / Manual Therapy 9 (2004) 164–172

Table 2 Coupled lumbar motion with side bending initiation (neutral, extension, and flexed spine) 3-D studies on asymptomatic subjects Author

L1–2

L2–3

L3–4

L4–5

L5–S1

Neutral spine Schultz et al. (1979) Pearcy and Tibrewal (1984) McGlashen et al. (1987) Panjabi et al. (1989) Panjabi et al. (1994) Cholewicki et al. (1996)

None None None None or same None Opposite or none

None Opposite None Opposite Opposite Opposite or none

None Opposite None Opposite Opposite Opposite or none

None Opposite None Opposite Opposite Same

None Opposite or none None Opposite Opposite Opposite

Extended spine Schultz et al. (1979) Vincenzino and Twomey (1993) Panjabi et al. (1989)

None Opposite Same or none

None Same Opposite

None Opposite Opposite

None Same Opposite

None Opposite Opposite

Flexed spine Vincenzino and Twomey (1993) Panjabi et al. (1989)

Same or none Same or opposite

Opposite Opposite

Same Opposite

Opposite Opposite

Same or none Opposite

including background of this sample is presented in Table 3. The physiotherapists were voluntary members of a continuing education course entitled ‘‘Intermediate Spinal Mobilization,’’ administered at different locations in the contiguous United States. This course was selected because it was the first course in a manual therapy series and the course participants represented diverse backgrounds. The survey was voluntary and approved by the local University Institutional and Ethics Review Board. 2.2. Procedure The survey was administered during the pre-registration period, prior to the initiation of the coursework. This prevented a pre-biasing regarding lumbar coupling biomechanics and allowed the subject to record their response based on their present knowledge of spinal coupling. The physiotherapists were provided written instructions requesting that they answer the questions to the best of their ability. The survey consisted of 11 questions; the first four consisting of Likert-type questionnaires associated with (1) How important do you feel the theory of lumbar coupling biomechanics is in your application of manual therapy? (2) How important do you feel lumbar coupling biomechanics is in validating manual therapy? (3) How often do you consider or use lumbar coupling biomechanics during your manual therapy treatment? and (4) How often do you use manual therapy in your treatment of the lumbar spine? Further questions were associated with frequency of manual therapy course attendance, manual therapy background or discipline, educational degree, years of practice experience, age, and gender. Since most manual therapy techniques include side bending initiation methods (Stoddard, 1972; Beal, 1989; Kappler, 1989; Nyberg, 1993; Hartman, 1997), a

Table 3 Demographics of survey participants Age 20–29 30–39 40–49 50–59

144 171 50 4

Gender Male Female

155 214

Years of experience 0–5 years 6–10 years 11–20 years Greater than 20

218 98 46 7

Physical therapy education Bachelors Masters Doctoral

168 191 10

Background Cyriax Maitland McKenzie Paris Other—not designated None Osteopathic Kaltenbourne IAOMa Mulligan Grimsby NAIOMTb

28 76 126 29 47 33 2 12 3 5 5 3

a b

International Academy of Orthopedic Medicine. North American Institute of Orthopaedic Manual Therapy.

question was selected associated with hypothetical coupling direction during active side bending initiation. The coupling direction question consisted of a blank


table with a set of five rows corresponding to the lumbar segments L1–2 through L5–S1, and three sub-rows corresponding to the postural positions of neutral, flexion, and extension. Three columns divided all rows outlining the choices of ‘‘opposite,’’ ‘‘same,’’ and ‘‘no coupling.’’ The question ‘‘please identify which direction you feel the corresponding segment will rotate at each of the designated levels, when active left side bending is initiated’’ was asked, allowing the participants to conceptualise which direction coupling should theoretically occur. This allowed participants to choose the direction of lumbar coupling rotation during active side bending in neutral, flexion and extension, for all five levels of the lumbar spine. Participants were asked to place an ‘‘X’’ in the column choice marked ‘‘opposite,’’ ‘‘same,’’ or ‘‘no coupling.’’ Since the data are categorical, missing values were not replaced and were recorded as ‘‘don’t know.’’

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coded allowing individualized association to the dependent variable. Since the dependent variable values consist of ranks without order, the actual values taken on by the dependent variable are irrelevant except that larger values are assumed to correspond to probability of changing one lower Likert choice to one ‘‘higher’’ outcome, and vice versa (Field, 2001). Since the coupling choices were nominal/categorical, and the sample consisted of a number of raters, a Fleiss Kappa coefficient was used to determine agreement on coupling direction (Uebersax, 1987; Feinstein and Cicchetti, 1990; Portney and Watkins, 2000). According to Fleiss (1981), values exceeding 0.75 suggest strong agreement above chance, values in the range of 0.40 to 0.75 indicate fair levels of agreement above chance, and values 0.40 are indicative of poor agreement above chance levels. SAS version 8.0.1 was used in place of SPSS, since SPSS does not have a multi-rater function for Kappa.

2.3. Statistical analysis Because the survey questionnaire was not a preexisting instrument, validation was necessary prior to inference of findings. Using SPSS version 11.0.1, an exploratory factor analysis with varimax rotation was used to determine if the current format of survey questions were appropriate. The exploratory factor analysis also included the Kaiser Meyer Olin (KMO) statistic, used to determine if the sum of partial correlations are greater than the sum of correlations, the Anti Image Correlation, which measures the strength of the sum of correlations, and Bartlett’s Test for Sphericity, a test for normalization of the sample and the potential relationship it may yield. Eigenvalues were extracted if greater than 0.5 a cut-off relevant for a sample size of 200 to 300 (Field, 2001). This method would serve to limit the latent variables to those that are most indicative of the variance pool within the study. The use of a factor analysis is appropriate on a sample size of 300 or greater, and is crucial in determining if the latent variables stand up on their own (Field, 2001). Additionally, power for a regression analysis generally required 10–15 respondents per question, and required a priori sample size of 220–315. Three separate ologit regression analyses were performed (Dependent Variable-1 importance of coupling to their treatment, Dependent Variable-2 importance of coupling to validation of manual therapy, Dependent Variable-3 use of coupling during manual therapy) to determine which independent factors were most influential to determining coupling biomechanics importance and use. An ologit regression analysis fits ordered logit models of an ordinal (polytomous) dependent variable against the selected independent variables. Independent variables can exist using any form of data; those variables that are nominal and ordinal are dummy

3. Results 3.1. Survey questionnaire validation The survey questionnaire did meet the power and validation requirements for the study. The Kaiser– Meyer–Olkin was 0.885 (0.5 and above indicates sample adequacy) suggesting that patterns of correlations are relatively compact so component analysis should yield distinct and reliable factors. The Bartlett’s test for Sphericity was significant (Pp0:0001; w2 ¼ 10; 723:1). The Bartlett’s test indicates that the sample does include relationships between variables, therefore component analysis was appropriate. The survey had no questions that required elimination after assessment of the antiimage correlation; all were above the correlation value of 0.7. The varimax component matrix indicated four main extractions consisting of constructs analogous to Likert-scale questions on coupling importance of use, validation, frequency, and use of manual therapy in the clinic. 3.2. Descriptive findings Eighty five point one (85.1%) percent of the participants indicated that lumbar coupling biomechanics was ‘‘very important’’ or ‘‘important’’ in their application of manual therapy. Only two participants identified coupling mechanics as ‘‘definitely not important.’’ Seventy eight point eight (78.8%) percent of participants indicated that the theory of lumbar coupling biomechanics is ‘‘very important’’ or ‘‘important’’ in validating manual therapy. Ninety three point two (93.2%) percent of the participants reported they ‘‘frequently’’ or ‘‘consistently’’ used lumbar coupling



biomechanics during their application of manual therapy. Lastly, 88 percent indicated the use of manual therapy ‘‘frequently,’’ ‘‘somewhat frequently,’’ or ‘‘sometimes’’ in the treatment of low back patients. 3.3. Inferential findings 3.3.1. First ologit regression The model fit value for the first ologit regression was significant (Pp0:0001; w2 ¼ 456:2). The Nagelkerke pseudo R2 was 0.71 indicating that the goodness of fit within this model is very good. The Nagelkerke pseudo R2 measures the explanatory power of the model, a similar concept to the regression coefficient in a linear model (Long, 1997). The first ologit regression using the dependent variable ‘‘how important the theory of lumbar coupling biomechanics is in your application of manual therapy’’ yielded several significant results. First, the likelihood that one rated the theory of lumbar coupling biomechanics toward the concept of ‘‘importance’’ was significantly associated with their frequency of use of coupling biomechanics in a clinical practice (Pp0:0001). The more frequent the consideration the higher the w2 ; indicating a higher assessment of importance. Second, only those who felt that lumbar coupling biomechanics was ‘‘very important’’ in validation of manual therapy, were likely to consider the approach significant in their application of manual therapy (P ¼ 0:001; w2 ¼ 10:28). Third, both clinicians with a bachelors (Pp0:0001; w2 ¼ 13:91) and a master’s degree (P ¼ 0:002; w2 ¼ 10:02) considered lumbar coupling biomechanics important in their application of manual therapy. The first ologit regression results are outlined in Table 4. 3.3.2. Second ologit regression The model fit value for the second ologit regression was significant (Pp0:0001; w2 ¼ 537:5). The Nagelkerke pseudo R2 was 0.687, also indicating that the goodness of fit within this model is also very good. The second ologit regression using the dependent variable ‘‘how important the theory of lumbar coupling biomechanics is in validating manual therapy’’ yielded many signifi-

cant results. First, those who ‘‘sometimes’’ (P ¼ 0:028; w2 ¼ 4:83) or ‘‘rarely’’ (P ¼ 0:047; w2 ¼ 3:95) considered lumbar coupling biomechanics in their application of manual therapy did not feel lumbar coupling biomechanics was critical for validation of manual therapy. Second, those who felt lumbar coupling biomechanics was ‘‘very important’’ (Pp0:0001; w2 ¼ 21:1) ‘‘important’’ (P ¼ 0:004; w2 ¼ 8:18) or had ‘‘no opinion’’ (P ¼ 0:027; w2 ¼ 4:91) of lumbar coupling biomechanics during their application of manual therapy were significantly likely to report the necessity of validation. Third, those with a bachelor’s (P ¼ 0:008; w2 ¼ 6:93) and a master’s (P ¼ 0:024; w2 ¼ 5:08) level of education did not feel lumbar coupling biomechanics was important in validating manual therapy. Those with a doctorate degree did not achieve significance. Lastly, those who ‘‘rarely’’ (P ¼ 0:02; w2 ¼ 4:33) used manual therapy in their application to the spine were more likely to report the necessity of lumbar coupling biomechanics for the validation of manual therapy. The second ologit regression results are presented in Table 5.

3.3.3. Third ologit regression The model fit value for the third ologit regression was significant (Pp0:0001; w2 ¼ 677:28). The Nagelkerke pseudo R2 was 0.586 indicating that the goodness of fit within this model is good. The third ologit regression using the dependent variable ‘‘how important the theory of lumbar coupling biomechanics is in your application of manual therapy treatment’’ yielded few significant results. First, those who used manual therapy ‘‘sometimes,’’ (Pp0:0001; w2 ¼ 24:72) ‘‘consistently,’’ 2 (Pp0:0001; w ¼ 19:9) and ‘‘frequently’’ (Pp0:0001; w2 ¼ 15:8) were likely to report the consideration of lumbar coupling biomechanics during manual therapy treatment. Those who felt lumbar coupling biomechanics were ‘‘very important,’’ ‘‘important,’’ ‘‘somewhat not important’’ and had ‘‘no opinion’’ in validating manual therapy were all likely to report the consideration or use of coupling during treatment (P ¼ 0:001; w2 ¼ 10:1). The third ologit regression results are presented in Table 6.

Table 4 Ologit Regression 1: ‘‘How important do you feel the theory of lumbar coupling biomechanics is in your application of manual therapy?’’ Variable

B

SE

Wald w2

Coupling used during manual therapy (‘‘Frequently’’) Coupling used during manual therapy (‘‘Consistently’’) Coupling used during manual therapy (‘‘Sometimes’’) Physical therapy degree (Bachelors) Coupling used during manual therapy (‘‘Rarely’’) Coupling important for validation (‘‘Very Important’’) Physical therapy degree (Masters)

5.72 5.33 4.37 3.18 3.63 5.04 2.59

1.02 0.987 0.950 0.852 1.06 1.57 0.819

31.46 29.19 21.23 13.94 11.66 10.28 10.02

Indicates level of significance Pp0.05. Indicates level of significance Pp0.0001. Only variables that were significant (Pp0.05) are reported.


169

Table 5 Ologit Regression 2: ‘‘How important do you feel the theory of lumbar coupling biomechanics is in validating manual therapy?’’ Variable

B

SE

Wald w2

Physical therapy degree (‘‘Bachelors’’) Use of manual therapy in back treatment (‘‘Rarely’’) Physical therapy degree (‘‘Masters’’) Coupling used during manual therapy (‘‘Rarely’’) Coupling used during manual therapy (‘‘Sometimes’’)

2.28 2.02 1.91 2.01 1.95

0.867 0.885 0.850 1.03 0.888

6.93 5.23 5.08 4.83 3.95

Indicates level of significance Pp0.05. Only variables that were significant (Pp0.05) are reported.

Table 6 Ologit Regression 3: ‘‘How often do you consider or use lumbar coupling biomechanics during your manual therapy treatment?’’ Variable

B

SE

Wald w2

Use of manual therapy in back treatment (‘‘Frequently’’) Use of manual therapy in back treatment (‘‘Consistently’’) Use of manual therapy in back treatment (‘‘Sometimes’’) Coupling necessary for validation (‘‘Very Important’’) Coupling necessary for validation (‘‘Important’’) Coupling necessary for validation (‘‘No Opinion’’) Coupling necessary for validation (‘‘Somewhat not Important’’)

4.14 3.65 3.27 5.14 4.15 3.79 3.57

0.832 0.819 0.818 1.62 1.63 1.65 1.65

24.72 19.90 15.98 10.00 6.46 5.24 4.65

Indicates level of significance Pp0.05. Indicates level of significance Pp0.0001. Only variables that were significant (Pp0.05) are reported.

Table 7 Inter-therapist reliability of perception of coupled motion during side bending initiation Spinal level

Fleiss Kappa statistic

L1–2 L2–3 L3–4 L4–5 L5–S1

0.10 0.11 0.09 0.10 0.09

Table 7 outlines the Fleiss Kappa value for each lumbar segment. Spinal segment L1–2 was 0.10; L2–3 was 0.11; L3–4 was 0.09; L4–5 was 0.10; and L5– S1 was 0.09. A negative Kappa means that there is less agreement than expected by chance given the marginal distributions of ratings.

4. Discussion The findings of this study indicate that physiotherapists support the importance of lumbar coupling biomechanics for practice use and validation. The majority of the surveyed participants reported that lumbar coupling biomechanics was important in their application of manual therapy. A greater share also reported that lumbar coupling biomechanics is important or very important in validating manual therapy. Nearly all of the participants claimed they used coupling theory at least sometimes during application of manual

therapy. Yet, it is apparent that the ‘‘directional concept’’ associated with lumbar coupling biomechanics is highly variable among survey participants. The results of each Kappa statistic of each spinal level indicates that there is wide disparity in which coupling theory physiotherapists’ utilize during biomechanical assessment and treatment of the lumbar spine. Regardless of level, the agreement among therapists for a preconceptual assessment of lumbar coupling motion was poor. A negative Kappa value indicates that the agreement among therapists is actually worse than chance (Landis and Koch, 1977). If the clinicians truly use the directional application of coupling, a concept supported in this survey’s findings (93.2 percent claim use of lumbar coupling) and by the literature (Fryette, 1954; Faye, 1984; Gertzbein et al., 1986; Plaugher, 1993; Gracovetsky et al., 1995; Winkel et al., 1996; Lund et al., 2002), then many clinicians are using conflicting conceptual approaches. Since an overwhelming number of survey participants indicate the use of lumbar coupling for treatment, it is likely that selected directional approaches are practiced. Significance in this study was associated with the preconceptual importance placed upon lumbar coupling biomechanics. Frankly stated, lumbar coupling biomechanics, regardless of which directional model committed to, was used by clinicians who felt it was important for validating and appropriately treating patients. In all three ologit results, with the exception of educational degree, the likelihood that one used, reported consideration of, and felt the importance of



lumbar coupling biomechanics for validation of manual therapy was highly correlated. This suggests that the direction of lumbar coupling is likely based on a previous assumption, a previous learned model, or a theory that plays a great deal of importance in the application of most manual therapists, despite the fact that physiotherapists cannot seem to agree on which direction that theory best describes lumbar coupling. Strangely, those therapists with both bachelor’s and master’s levels of education reported ‘‘importance’’ of lumbar coupling biomechanics in their application of manual therapy, though they did not feel lumbar coupling biomechanics was necessary in validating manual therapy. At face value, it appears to be a contrasting concept. There was no trend toward older or younger, or more or less experienced clinicians stating a preference in one coupling pattern or level of importance versus another. Other than degree, it appears any clinician is just as likely to report the ‘‘importance’’ of lumbar coupling theory regardless of background. The findings of this study somewhat replicate the findings of 3-D lumbar coupling biomechanical literature, which for several years has presented disparate directional findings in lumbar coupling research (Schultz et al., 1979; Pearcy and Tibrewal, 1984; McGlashen et al., 1987; Panjabi et al., 1989; Vincenzino and Twomey, 1993; Panjabi et al., 1994; Cholewicki et al., 1996). Recent 3-D analyses of coupling motion support the theory that lumbar coupling direction is unpredictable, even during analysis of nonpathological subjects. The affect of an injury further complicates the findings of coupled motion with recent studies reporting variances, in both quantity and directional coupling behaviour (Panjabi et al., 1984; Gertzbein et al., 1985, 1986; Parnianpour et al., 1988; Gracovetsky et al., 1995; Kaigle et al., 1995, 1998; Lund et al., 2002). No studies were found that identify a predictable, pathological lumbar coupling pattern that correlates with a specific pathology. The ability to predict pathological coupling patterns during assessment would be dependent on repeatable coupling consistency between pathological and non-pathological subjects. To designate a motion as abnormal spinal coupling ‘‘requires knowledge of the normal motions’’ (Panjabi et al., 1994). Parameters of normal spine coupling are unavailable (Harrison et al., 1998). The possibility exists that educational programs and continuing education groups are teaching selective, conflicting results from updated 3-D studies on directional-coupled motion (Cook et al., 2002). This could account for the inconsistency of findings, specifically associated with the poor Kappa values. Despite this possibility, there were no backgrounds (i.e., Maitland, McKenzie, etc.) that were significantly associated with lumbar coupling. Though not significant (a ¼ 0:05) all backgrounds reported a positive beta estimate, indicat-

ing an assumed importance of lumbar coupling biomechanics in the treatment, validation, and assessment of low back patients. The data did not define one background that placed a greater amount of importance in lumbar coupling versus another. This study’s findings support culminating evidence that basing manual therapy techniques on the assumption that a single directional coupling pattern exists for all patients is erroneous. Pertinent lumbar spine coupling assessment appears to depend on the anatomical differences, posture and pathology of each individual. Since many coupling movements are on the order of 1–1.1 mm per segment this form of assessment may not be clinically significant (Panjabi et al., 1994). Directional coupling assessment may be beyond the skilled practitioners’ ability to ‘‘feel’’ the finite movements (Harrison et al., 1998) and since pathologies do not yield specific directional findings, the information obtained may actually yield little clinical value (Panjabi et al., 1994). Coupling motion assessment may not provide the manual therapist with accurate or useful information unless the pattern of coupling fits that particular patient (Harrison et al., 1998). 4.1. Limitations of the study The findings of this survey were drawn from participants of one manual therapy continuing education programme. This approach does not rely heavily on directional coupling patterns of the lumbar spine for assessment and treatment. The possibility exists, though unlikely according to the level of importance most clinicians placed on coupling biomechanics, that the participants of the course selected the manual therapy continuing education course based on this reason. Nearly 95 percent of the survey respondents indicated coupling motions were important in their application of manual therapy, a figure that does not support a nonadherence to coupling principles. Additionally, it is likely that many of the course participants categorized their approach on a background or discipline in which they were not versed or skilled in. Many indicated that their approach did not follow one specific background and selected ‘‘other.’’ The possibility exists, that one’s exposure to a particular manual therapy model included incorrect or misinformation, thus reducing the purity of this model. Lastly, these findings are limited to United States clinicians; generalization to non-US clinicians is unwise.

5. Conclusion This study found that a sample of practicing clinicians participating in a manual therapy course place a high level of importance on lumbar coupling biomechanics,


but did not agree on the direction of coupled motion of lumbar spine. The poor agreement is not indicative of background differences, age, years of experience, gender, or exposure to past manual therapy courses. The importance of lumbar coupling biomechanics for use, validation and frequency seems to be predicated on the internal importance of lumbar coupling conceptualised by each clinician. Indeed, lumbar coupling associated with quantity of motion for detection of hypo and hypermobility may be beneficial. Yet, the majority of lumbar coupling assessment methods involve directional analysis of coupling patterns. In this study, each clinician’s concept of lumbar coupling direction is not consistent. Future research should investigate whether clinicians can accurately detect coupled motion as determined by 3-D research. Additionally, future investigation whether coupling findings in the clinic are reflective of preconceived coupling motion is worth exploration.

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ARTICLE IN PRESS



Case report

A case of selective paresis of the deep stabilization system due to boreliosis K. Lewit*, O. Horacek Rehabilitation Department, 2nd Medical Faculty, Charles University, Prague, Czech Republic Received 29 May 2003; received in revised form 30 July 2003; accepted 5 April 2004

1. Introduction As a result of the pioneering research undertaken by physiotherapists in Australia (Wohlfahrt and Jull, 1993; O’Sullivan et al., 1997; Richardson et al., 1999) clinical professionals working in the area of musculoskeletal dysfunction have become increasingly aware of the crucial importance of what may be called the ‘‘Deep Stabilization system’’. Even before this our attention was indirectly drawn to the same problem by Silverstolpe’s findings (Silverstolpe, 1989). This author demonstrated that on snapping-palpation of highly active trigger points (TrPs) of the thoracic erector spinae, extension of the lumbar spine and pelvis was obtained, by contraction of the lumbar erector spinae. This has been confirmed by electromyography (EMG) (Skoglund, 1989). Concomitantly, a pain point is identified with palpation of the sacrotuberous ligament. Following massage of this pain point, the TrP in the spinal erector and the tender point in the buttocks and a whole chain of other symptoms vanished. In honor of Silverstolpe and Skoglund this whole complex is called the ‘‘S’’ reflex (Fig. 1). Not only was it possible to confirm Silverstolpes’ findings, but it was soon noted that it was possible to obtain release by mere pressure in the same direction. This, however, is a characteristic for a muscular TrP. Therefore it was concluded that this phenomenon was due to a TrP of the underlying coccygeus muscle, part of the pelvic floor. Learning how to relax the coccygeus muscle soon proved that it was indeed the pelvic floor. This became a clinical priority, because, however effective the treatment by massage and/or pressure was, the clinical complaints had a tendency to recur at very short intervals, and treatment was very unpleasant.

*Corresponding author. 1356-689X/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2004.04.003

Once, however, the patient learned how to relax the pelvic floor (Lewit, 1999a), the results were as prompt and satisfactory as after pressure and/or massage. The patient can easily do this several times a day on his own. Pressure palpation is most important in the diagnosis of pelvic floor involvement. At present this is known to be much more frequent than the characteristic ‘‘S’’ reflex. Not less important is snapping palpation of the diaphragm for TrPs, which are equally frequent and no less important. No single muscle is responsible for the stability of the lumbar spine, but rather an orchestrated co-activation of agonist and antagonist muscles surrounding the spinal column is necessary (Cholewicki and McGill 1996; Cholewicki et al., 1997). The abdominal cavity being a fluid filled space is as firm as the weakest of its walls. Through the diaphragm, moreover, postural function is linked with respiration (Fig. 2). The practical consequence for clinical management of myofascial pain is that painful TrPs which are found mostly in the superficial muscles mainly involved in voluntary movement, very often clear up after adequate treatment of the deep stabilization system, mainly involved in posture. The influence of the postural function on voluntary movement was admirably shown by Hodges and colleagues using EMG (Hodges and Richardson, 1996; Hodges et al., 1996). They demonstrated that if a healthy subject raises his arm, the transversus abdominis contracts before the deltoid. These findings are almost experimentally confirmed by the following case.

2. Clinical history The patient was first seen by one of the authors on August 28, 2001. At that time her main complaint was


K. Lewit, O. Horacek / Manual Therapy 9 (2004) 173–175

Fig. 1. Diagram showing the typical site of TrPs of the thoracic erector spinae, the gluteal pain point and the direction of palpation of the M. coccygeus.

back pain. She had two normal deliveries and a gynecological operation in 1978. Examination findings: The patient was able to lift her arms when seated, but when standing only if the pelvis was supported. There was not only a tendency to ‘‘stick out her tum’’ but also to sway back on stooping. There were neither painful lesions nor was there any movement restriction. There was marked weakness of her back muscles and of the deep abdominal muscles exclusively. There was in addition hypertonus of the scalenes and the sternocleidomastoids; the tendon reflexes in her upper extremities were very lively, but muscle tone was decreased. Abdominal reflexes were absent. The patellar reflexes were symmetrical but the Achilles tendon reflexes lowered, as was the perception of vibration on the feet. An EMG examination was requested not of her extremity muscles but of her trunk muscles. This was not forthcoming and for that reason the patient was seen again as late as April 22, 2002. In the meantime she was provided with a corset and was given more rehabilitation, mainly for her back muscles. She was slowly improving. By then when standing with a corset she could lift her arms normally, but without the corset only with considerable difficulty. At re-examination it was noted that she was still unable to lift her head and/or her legs when lying prone, and that she could not draw in her navel, even though her straight abdominal muscles functioned normally. The diaphragm was contracting normally (X-rays in inhalation and exhalation), but there was clearly faulty respiration, because during inhalation she lifted her thorax without widening it, using mainly her scalenes (Lewit, 1999b). These findings were documented on videotape. The EMG of her back muscles confirmed the paresis (Fig. 3).

Fig. 2. Palpation of the diaphragm.

that standing in front of her sink her ‘‘tummy was sticking out’’ and that when standing she was unable to lift her arms, yet while sitting she could do so without difficulty. EMG of her deltoid was normal. So unusual was this finding that the patient was suspected of malingering. Her problems began with back pain during the summer of 2000. The patient’s condition became worse during the autumn to the extent that she became paralyzed and she was unable to walk. She was therefore hospitalized in November 2000 and boreliosis was diagnosed. In the course of her stay in hospital she slowly improved so that after discharge she could walk almost normally, but because of the complaints already mentioned she was sent to our rehabilitation department. In her previous history she never suffered from

Fig. 3. Needle EMG of the low cervical and thoracic M. multifidi showing bilateral signs of chronic neurogenic lesion.

ARTICLE IN PRESS K. Lewit, O. Horacek / Manual Therapy 9 (2004) 173–175

3. Discussion This patient became severely paralyzed in the course of boreliosis. This is a tick born infection due to the spirochete Burgdorferi, also known as Limes disease after the locality, where it was first described. As such it has many features in common with syphilis including late neurological symptoms, as in this case. Like syphilis it is treated by penicillin. After partial recovery, her back muscles and the transversus abdominis remained weak and there was faulty respiration, requiring substitution of her scalenes. In other words: her back muscles and her abdominal muscles, i.e. her abdominal cavity did not stabilize her lumbar spine. This made her unable to lift her arms when standing freely. The moment the pelvis was fixedseated or standing with a corset, she could lift her arms properly. It also showed the close relationship between posture and respiration. With a weak transversus abdominis the diaphragm was not supported by the abdominal cavity so that the scalenes had to lift the thorax during inhalation. This case is exceptional in that paralyzed deep stabilizers caused impairment of active shoulder movements. In our daily routine we see, on the other hand that dysfunction of the deep stabilizers harboring TrPs, is inadequately compensated by long superficial muscles, which react by painful TrPs on their part. When Magnus (1925) pointed out that ‘‘posture follows movement like a shadow’’, we have to now say even more pointedly—‘‘without posture, no movement’’.

4. Conclusion Research by Hodges and Richardson (1996) has shown that during arm lifting the transversus abdominis

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contracts before the deltoid in normal subjects. By contrast a case is reported in which a patient with paresis of the back and deep abdominal muscles had difficulty in lifting her arms when standing freely.

References Cholewicki J, McGill SM. Mechanical stability of the in vivo lumbar spine: implications for injury and chronic low back pain. Clin Biomech 1996;11(1):1–15. Cholewicki J, Panjabi MM, Khabatiken AL. Stabilizing function of the trunk flexor–extensor muscles around a neutral spine posture. Spine 1997;19:2207–12. Hodges P, Richardson C. Insufficient muscular stabilization of the lumbar spine associated with low back pain. Spine 1996;21: 290–2. Hodges P, Richardson C, Jull G. Evaluation of the relationship between laboratory and clinical tests of transversus abdominis $ function. Physiotherapy Res Internet 1996;1:30–40T. Lewit K. Panevni dno a stabilizacni system (The pelvic floor and the stabilization system). Rehabil.afyzik L 1999a;6:46–8. Lewit K. Manipulative therapy in rehabilitation of the motor system. 3rd ed. Oxford: Butterworth-Heinemann; 1999b. p. 28,241. Magnus R. Cronian lecture—animal posture. Proc Roy Soc 1925;B 98:339. O’Sullivan P, Twomey L, Allison G. Evaluation of specific stabilizing exercise in the treatment of chronic low back pain with radiologic diagnosis of spondylolysis or spondylolisthesis. Spine 1997;24: 2959–67. Richardson C, Jull G, Hodges P, Hides J. Therapeutic exercise for spinal stabilization in low back pain. Edinburgh: Churchill Livingstone; 1999. Silverstolpe I. A pathological erector spine reflex—a new sign of mechanical pelvis dysfunction. J Manual Med 1989;4:24. Skoglund CR. Neurophysiological aspects of the pathological erector spinae reflex in cases of mechanical pelvis dysfunction. J Manual Med 1989;4:29. Wohlfahrt D, Jull G. The relationship between the dynamic and static abdominal muscles. Austr Physiotherapy 1993;39:9–13.

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Abstracts

Manipulation Association of Chartered Physiotherapists (MACP) UK Research Awards MACP Research Awards For Full Members The MACP has two awards, available annually to full members, designed to encourage research in the field of manipulative physiotherapy. These awards offer members the opportunity to have their research proposals peer reviewed and potentially funded up to £2000.00.

investigate the features important for the potent formation of homogenous subgroups of classified LBP sufferers in Greece, and explore the similarities and differences between the Greek and the UK features, obtained by Greek and UK clinicians, respectively. Methods

Elsevier Science Award for Research in Manipulative Physiotherapy The close links between the MACP and Elsevier Science have resulted in an award, sponsored by Elsevier Science, which encourages members to undertake research in the field of manipulative physiotherapy. Up to £2000 is available to applicants with one award being available annually. Full details can be obtained from Terry Smith on macp [email protected]. The closing date for applications is the 30th of July 2004.

For this purpose, a panel of experienced clinicians in each country will be created (focus group), to develop a list of diagnostic features important for establishing potentially homogenous LBP subgroups. In order to obtain a professional consensus and hierarchy, the most important ‘‘classified factors’’ for each country, a Delphi survey approach will be carried out. Each country’s results from the focus group and the Delphi survey will be compared. Future research should evaluate these factors on LBP patients in an attempt to develop clusters of smaller homogenous subgroups.

References

Elsevier Science Award for Research in Manipulative Physiotherapy Winner 2003 Evdokia Vicky Billis Important features in identifying homogenous subgroups in classifying low back pain patients: A cross-cultural comparative analysis between Greek and UK health professionals Introduction Identifying homogenous subgroups of non-specific low back pain (LBP) patients is considered a priority in physiotherapy and is believed to enhance clinical outcomes (Borkan et al., 1998). However, prior to forming these subgroups, more information is needed in two particular areas: factors to be included within each subgroup, and whether cultural differences can influence these classified features. This research study aims to doi:10.1016/j.math.2004.04.001

Borkan J, Koes B, Reis S, Cherkin D. A report from the second international forum for primary care research on low back pain. Spine 1998;23(18):1992–6.

Doctoral Level Study Award The MACP is keen to encourage its members in pursuing their post-graduate education. There is a recognition within the association that an increasing number of the membership are undertaking doctoral level studies. In order to support the work of the members, undertaking doctoral level studies within the field of musculoskeletal physiotherapy, invitations for applications are invited from full members registered for doctoral level study degrees. Up to £1000 pounds may be applied for, with two awards being available annually. Full details can be obtained from Terry Smith on macp [email protected]. The closing date for applications is the 30th of July 2004.

ARTICLE IN PRESS Abstracts / Manual Therapy 9 (2004) 176–177

Doctoral level study award winner 2003 Alison Rushton An exploration of the construct of masters level clinical practice in specialist manipulative physiotherapy Introduction Growing emphasis on Masters level provision in the UK has been facilitated by the migration of education into Higher Education and the requirement for Continuing Professional Development. Paralleling this has been the development of specialization in clinical practice. These factors have contributed to a proliferation of Masters courses aiming to develop specialist clinical practice. The aim of this study was to explore the behaviour indicative of the construct of Masters level clinical practice in particular, within manipulative physiotherapy.

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data using a constant comparative process until saturation of the data were achieved. Theoretical propositions were then developed.

Results The response rate for the Delphi study was very good. There was good consensus amongst the 28 behaviours received for round 1. Round 2 achieved good consensus enabling 21 agreed very important behaviours to be taken into round 3. The ranking process in round 3 afforded good consensus and highlighted the importance of for example, a critical approach to practice and advanced clinical reasoning. The case study facilitated further insight into the construct by identifying advanced clinical reasoning as the most important behaviour for manipulative physiotherapy. This was then subdivided into core components for example, adaptability of practice.

Discussion Methodology The study is framed within the philosophical tradition of phenomenology. It uses a mixed method approach and quantitative and qualitative data, using methodological triangulation to contribute to an understanding of the construct. The conceptual framework was informed by two prior stages: a critical analysis of the literature relating to clinical education (Rushton and Lindsay, 2003), and a descriptive survey of the current practice in Masters courses aiming to develop clinical expertise (Rushton, 2003). A Consensus of Masters level behaviours indicative of the construct was explored through a Delphi approach. A total population sample of all course tutors of Masters courses in the UK assessing clinical practice (n=48) were invited to participate, with 38 participants agreeing (n=7 for manipulative physiotherapy). Round 1 asked for behaviours indicative of the construct. Data were analyzed through content analysis, which subsequently informed the behaviours in round 2, where participants rated the importance of each behaviour on a scale of 1–5. Round 3 asked participants to rank the importance of the different behaviours to the construct. Descriptive analysis and the use of Kendall’s coefficient of concordance and Spearman’s rho enabled the interpretation of consensus in rounds 2 and 3. The construct was also explored through an in-depth case study in its real life context. Multiple methods were employed from the qualitative paradigm, including documentary analysis, semistructured interviews, and participant observation. Purposive sampling selected the ‘case’ of a manipulative physiotherapy course within one university. Analytic categories were derived from the

The identified general behaviours that were agreed by course tutors as central to the construct were also reflected in the findings from the case study, although the case study data subdivided the key behaviours further into more specific components of specialist practice.

Conclusion Through methodological triangulation, this study has identified behaviours indicative of the construct of Masters level clinical practice in general terms and for manipulative physiotherapy. It would be appropriate to develop this work further by exploring several cases to enable analytic generalization. This work can subsequently contribute to the development of a set of items that can be used for assessment purposes, therefore contributing to evidence-informed practice in specialist manipulative physiotherapy. Report Complied by Dr C. McCarthy MACP Research Officer

References Rushton A, Lindsay G. Clinical education: a critical analysis using a soft systems methodology. International Journal of Therapy and Rehabilitation 2003;10(6):271–9. Rushton A. A descriptive survey exploring the characteristics of masters level courses aiming to develop clinical expertise in the UK. Platform presentation. 14th International WCPT Congress, Barcelona, Spain, 7–12 June, 2003.

ARTICLE IN PRESS



Book reviews Musculoskeletal injection skills Monica Kesson, Elaine Atkins, Ian Davies; Butterworth, Heinemann, London, 2002, 1st Edition, price d24.99, ISBN 0750643722 The primary aim of this book is to afford practical information to physiotherapists and doctors about injection techniques for musculoskeletal lesions. The text aims to support courses in injection therapy, run by the authors (two physiotherapists and one general practitioner). The first section (35 pages) provides basic information on pharmacology, equipment, safety precautions and general injection principles. The second part presents the technical description of intra-articular and intra-lesional injection techniques for peripheral musculoskeletal lesions. The injections are categorized into those of shoulder, elbow, wrist-hand, hip, knee and ankle-foot. Injection techniques for the temporo-mandibular joint, the cervical, thoracic and lumbar spine and the S-I joint are not described as they fall beyond the scope of the book. Each of the injections is presented in a consistent format, detailing indications, presentation, needle size, dosage, patient and therapist posture, palpation of the site, technique of the injection and aftercare. A photograph and a line drawing of landmarks and needle position accompany each technique. Though the photographs have a very good quality,

they focus only on skin and needle and do not afford additional information on position of the limb and palpable or visible landmarks. All together, 46 different injection techniques are presented. Some of these injections are very seldom indicated (f.i. intra-articular injection of the hip, calcaneocuboid joint) others are more often contra-indicated than indicated (olecranon bursitis, talocrural joint) and others are dangerous (long head of biceps brachii). On the other hand, a lot of commonly used and usually very successful infiltration techniques did not find a place in the book (infiltrations for ankle sprains, medial collateral ligament and cruciate ligaments of the knee, popliteus tendinitis, coracoid bursitis of the shoulder). A final remark is on the promotion of injecting corticosteroids in combination with a local anaesthetic. This is useless and even dangerous in case of an intraarticular injection. Manipulation of different vials, bottles, needles and syringes in order to compose an ‘injection cocktail’ will increase the risk of a dramatic and even life-threatening articular infection. In summary, this beautifully edited book is a practical guide for the doctor or physiotherapist who wants primary information about how to perform common musculoskeletal injections. Ludwig Ombregt Kanegemstraat 170 B-8891 Tielt, Belgium E-mail address: [email protected]

doi:10.1016/S1356-689X(03)00092-4

Modern neuromuscular techniques Leon Chaitow (Ed.); Churchill Livingstone, New York, NY, 2003 price d38,99, ISBN: 0443071586

At the first look the book appears to be a good descriptive work of different theories and manual techniques for the treatment of soft tissues and a useful guide to influence the patients health by reflexo-therapy. The text is clearly written and easy to read, the explanations allow the expert reader to transfer many techniques into practice. The layout is well organised and a helpful CD ROM is very useful. Beside this, there

are also some critical points regarding this book. The author refers to many secondary sources of information that are used as a foundation for the different chapters. The references are put in brackets and are authority based. These authorities are presented to guarantee the truth of the information, and are not critically reviewed. In some passages, esoteric concepts are introduced and suggested as useful elements of clinical reasoning (soft tissues changes—energy and fascial considerations, p. 22). The introduction to the viscerosomatic and somatovisceral reflexes could be interesting, but the reader could be thrown into confusion when the author follows

ARTICLE IN PRESS Book reviews / Manual Therapy 9 (2004) 178–180

this physiologic hypothesis and applies the diagnostic and therapeutic power of the so-called neurolymphatic and neurovascular reflexes (Chapman and Bennet). It is suggested that after reading this book, the reader could be able to diagnose and treat diffuse visceral symptoms and pathology (see Table 5.1 at page 103). The majority of the manual expertise presented in this book could be a good starting point for the improvement of the manual skills of therapists. However, a

179

thorough revision in the light of actual scientific evidence is needed: mainly authority-based books do not fit with the evidence-based trend of the last decade.

Marco Testa Faculty of Medicine and Surgery University of Genova Italy

doi:10.1016/S1356-689X(04)00003-7

The biomechanics of back pain M. Adams, N. Bogduk, K. Burton, and P. Dolan (Eds.); Churchill Livingstone, Edinburgh, 2000, 238pp., Price d27.99, ISBN 044306272 Bringing together a large experience in spinal anatomy, spinal biomechanics, the neurology and epidemiology of back pain, as well as their experience in ergonomics and exercise and muscle physiology in this field, the authors of ‘‘Biomechanics of Back Pain’’ conceived their book on a multidisciplinary basis. Scientific evidence of back pain related biomechanical research is presented at the service of health care workers, that means, with a basic accent on its clinical relevance. Instead of explaining back pain away by attractive explanation models, the authors made the choice to collect as much as scientific evidence possible for an important number of biomechanical mechanisms playing a role behind the multifaceted problem of back pain. They state that, in recent years, the balance of back pain research has perhaps swung too far towards psychosocial issues. The purpose of the present book is not to push the pendulum back again, but rather to bring it in a balanced position where all of the factors which influence back pain are given due attention. The introductory chapter contains a glossary of biomechanical terms and concepts, used later in the book. The following 2 chapters address the functional anatomy of the lumbosacral spine, the surrounding musculature and fasciae. These chapters can be seen as a short version of ‘‘Clinical Anatomy of the Lumbar and Sacrum’’ (Bogduk, 1997). An important number of the illustrations in these chapters are redrawn from this book. Chapter 4 addresses the biology of spinal tissues. Herein, attention is given to the structure and composition, the metabolism, and ageing and degeneration of muscle tissue, bone tissue, hyaline cartilage, spinal tendons and ligaments, and intervertebral discs.

In Chapter 5, documentation is given about the scientific evidence (or lack of evidence) concerning the aetiology of several back pain syndromes. Chapter 6 focuses on the epidemiology of low back trouble. The evidence presented in this chapter is mainly based on systematic reviews and completed with information from other papers. Genetic, individual, environmental and psychosocial risk factors for low back trouble are discussed with possible relationships to each other. Forces acting on the spine are treated in Chapter 7. Compressive loading of the spine, shear, bending and torsion are documented. The question: ‘‘where do the forces come from?’’ is answered, and followed by an introduction to the measuring methodology of spinal compression and spinal bending. Chapter 8 deals with the mechanical function of the lumbar spine. Several aspects of lumbar spine movements are discussed: range of motion (ROM), factors influencing the ROM, ROM measurement methodology, intersegmental movements versus whole lumbar spine movements, and coupled movements. The normal response of spinal tissues to non-damaging forces is documented after introductory remarks concerning the techniques used to investigate spinal function, based on a previously reported methodological review (Adams, 1995). The authors document the function of vertebrae, zygapophyseal joints, spinal ligaments, intervertebral discs, sacrum and sacroiliac joints. Chapter 9 is an extensive chapter about mechanical damage to the lumbar spine. Compression, shear, bending and torsion are treated in relationship to damage, injury and fatigue failure of spinal tissues. Attention is given to end plate fracture, disc prolapse, segmental instability, whiplash, spondylolysis and spondylolisthesis. The importance of posture, creep in spinal tissues and muscle function and dysfunction is extensively documented in Chapter 10, under the heading of functional pathology.

ARTICLE IN PRESS Book reviews / Manual Therapy 9 (2004) 178–180

this physiologic hypothesis and applies the diagnostic and therapeutic power of the so-called neurolymphatic and neurovascular reflexes (Chapman and Bennet). It is suggested that after reading this book, the reader could be able to diagnose and treat diffuse visceral symptoms and pathology (see Table 5.1 at page 103). The majority of the manual expertise presented in this book could be a good starting point for the improvement of the manual skills of therapists. However, a

179

thorough revision in the light of actual scientific evidence is needed: mainly authority-based books do not fit with the evidence-based trend of the last decade.

Marco Testa Faculty of Medicine and Surgery University of Genova Italy

doi:10.1016/S1356-689X(04)00003-7

The biomechanics of back pain M. Adams, N. Bogduk, K. Burton, and P. Dolan (Eds.); Churchill Livingstone, Edinburgh, 2000, 238pp., Price d27.99, ISBN 044306272 Bringing together a large experience in spinal anatomy, spinal biomechanics, the neurology and epidemiology of back pain, as well as their experience in ergonomics and exercise and muscle physiology in this field, the authors of ‘‘Biomechanics of Back Pain’’ conceived their book on a multidisciplinary basis. Scientific evidence of back pain related biomechanical research is presented at the service of health care workers, that means, with a basic accent on its clinical relevance. Instead of explaining back pain away by attractive explanation models, the authors made the choice to collect as much as scientific evidence possible for an important number of biomechanical mechanisms playing a role behind the multifaceted problem of back pain. They state that, in recent years, the balance of back pain research has perhaps swung too far towards psychosocial issues. The purpose of the present book is not to push the pendulum back again, but rather to bring it in a balanced position where all of the factors which influence back pain are given due attention. The introductory chapter contains a glossary of biomechanical terms and concepts, used later in the book. The following 2 chapters address the functional anatomy of the lumbosacral spine, the surrounding musculature and fasciae. These chapters can be seen as a short version of ‘‘Clinical Anatomy of the Lumbar and Sacrum’’ (Bogduk, 1997). An important number of the illustrations in these chapters are redrawn from this book. Chapter 4 addresses the biology of spinal tissues. Herein, attention is given to the structure and composition, the metabolism, and ageing and degeneration of muscle tissue, bone tissue, hyaline cartilage, spinal tendons and ligaments, and intervertebral discs.

In Chapter 5, documentation is given about the scientific evidence (or lack of evidence) concerning the aetiology of several back pain syndromes. Chapter 6 focuses on the epidemiology of low back trouble. The evidence presented in this chapter is mainly based on systematic reviews and completed with information from other papers. Genetic, individual, environmental and psychosocial risk factors for low back trouble are discussed with possible relationships to each other. Forces acting on the spine are treated in Chapter 7. Compressive loading of the spine, shear, bending and torsion are documented. The question: ‘‘where do the forces come from?’’ is answered, and followed by an introduction to the measuring methodology of spinal compression and spinal bending. Chapter 8 deals with the mechanical function of the lumbar spine. Several aspects of lumbar spine movements are discussed: range of motion (ROM), factors influencing the ROM, ROM measurement methodology, intersegmental movements versus whole lumbar spine movements, and coupled movements. The normal response of spinal tissues to non-damaging forces is documented after introductory remarks concerning the techniques used to investigate spinal function, based on a previously reported methodological review (Adams, 1995). The authors document the function of vertebrae, zygapophyseal joints, spinal ligaments, intervertebral discs, sacrum and sacroiliac joints. Chapter 9 is an extensive chapter about mechanical damage to the lumbar spine. Compression, shear, bending and torsion are treated in relationship to damage, injury and fatigue failure of spinal tissues. Attention is given to end plate fracture, disc prolapse, segmental instability, whiplash, spondylolysis and spondylolisthesis. The importance of posture, creep in spinal tissues and muscle function and dysfunction is extensively documented in Chapter 10, under the heading of functional pathology.


Book reviews / Manual Therapy 9 (2004) 178–180

Chapter 11 reviews the evidence for the efficacy and potential benefits of preventive strategies and current interventions. Eleven existing national clinical guideliness are compared. The chapter is concluded with practical advice. Chapter 12 raises some biomechanical issues and considers the available scientific evidence concerning some common medico-legal questions related to low back pain. In the final chapter a summary is presented around the topics spinal ageing, degeneration and pain. The authors try to integrate the evidence from genetics, biomechanics, biochemistry, cell biology and psychology to construct a comprehensive model of spinal ageing, degeneration and pain. All the chapters are well documented with 886 references and nicely illustrated. The book contains some remarkable colour photographs of different stages of lumbar intervertebral disc degeneration and pathology. A clear index completes this publication. In conclusion: the authors have succeeded in exploring the scientific evidence concerning the biomechanics of low back pain and present the results of their

doi:10.1016/S1356-689X(04)00005-0

multidisciplinary approach in a comprehensive and rational fashion. The style, the concept and the contents of the present work correspond to contemporary needs of scientific based health care education and health care work. Although ‘‘manual therapists’’ were not mentioned in the paragraph: ‘‘who should read this book’’, the book merits recommendation for manual therapy education and practice.

References Adams M. Mechanical testing of the spine. An appraisal of the methodology, results and conclusions. Spine 1995;20:2151–6. Bogduk N. Clinical anatomy of the lumbar Spine and sacrum. Edinburgh: Churchill Livingstone; 1997.

P. Van Roy Experimental Anatomy and Manual Therapy Departments Free University Brussels Belgium

Manual Therapy (2004) 9(3), 181

Diary of events

21–26 August 2005, Sydney, Australia

16, 17 & 18 September 2004, Provinciehuis Antwerp (Belgium)

11th World Congress on Pain, Workshop and Plenary Proposals. Please send proposals to the Chair of the Scientific Program Committee: Herta Flor, PhD, Central Institute of Mental Health, Dept of Clinical and Cognitive Neuroscience, PF 12 21 20, 68072 Mannheim, Germany. Tel: 49-621-170-3922; Fax: 49-621-170-3932; E-mail: fl[email protected] Workshop and plenary suggestions should be submitted by 15 March 2003 at the latest so that they can be considered by the Scientific Program Committee. Note that announcements, deadlines, and other information relating to the 2005 Congress will be routinely updated on the IASP Web page: www.iasp-pain.org

Movement Impairments and Stability Disorders in the Lower Quadrant. ‘‘European Course Tour 2004’’ with Dr. Serge Gracovetsky, Prof. Shirley Sahrmann, Sarah Mottram and Sean Gibbons. Organisation: Belgian Scientific Manual Therapy Association (BWMT). Contact ECT 2004 Bureau: Avignonlaan 57, B-8310 Brugge Tel: 0032 (0) 50 370528; Fax: 0032 (0) 26112968 & 0032 (0) 9 3699382; E-mail: mailto: [email protected] Website: http://www.belgianmedcare.com/bwmt 21–25 September, 2004, Barcelona, Spain 3rd World Congress World Institute of Pain, Pain: Advances in Research and Clinical Practice Contact Information: MEET2 LTD. Organizing Secretariat, P.O. Box 14264 Barcelona, 08080 Barcelona, Spain. Tel: +34 93 212 65 20; Fax: +34 93 417 22 79. Website: www.wipain@org. E-mail: [email protected]

Janet G. Travell, MD Seminar Series, Bethesda, USA For information, contact: Myopain Seminars, 7830 Old Georgetown Road, Suite C-15, Bethesda, MD 20814-2432, USA. Tel.: +1 301 656 0220; Fax: +1 301 654 0333; website: www.painpoints.com/seminars.htm; E-mail: [email protected] Evidence-based manual therapy congress Further information: www.medicongress.com

10–13 November, 2004, Melbourne, Australia 5th Interdisciplinary World Congress on Low Back & Pelvic Pain Effective Diagnosis and Treatment of Lumbopelvic Pain. Information and Call for Papers: www.worldcongresslbp.com http://www.worldcongresslbp.com Deadline submitting papers: December 15, 2003 For all further information: info@world congresslbp.com mailto: info@worldcongresslbp. com

Intensive courses in Manual Therapy Further information: http://allserv.rug.ac.be/bvthillo If you wish to advertise a course/conference, please contact: Karen Beeton, Department of Physiotherapy, University of Hertfordshire, College Lane, Hatfield, Herts AL10 9AB, UK. There is no charge for this service.

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Manual Therapy Journal - Volume 9, Issue 3, Pages 123-182 (August 2004)

Manual Therapy Journal - Volume 9, Issue 4, Pages 183-246 (November 2004)

Manual Therapy Journal - Volume 9, Issue 1, Pages 1-58 (February 2004)

Manual Therapy Journal - Volume 9, Issue 2, Pages 59-120 (May 2004)

Manual Therapy Journal - Volume 8, Issue 3, Pages 129-192 (August 2003)

Manual Therapy Journal - Volume 12, Issue 3, Pages 199-296 (August 2007)

Manual Therapy Journal - Volume 10, Issue 3, Pages 175-238 (August 2005)

Manual Therapy Journal - Volume 11, Issue 3, Pages 167-240 (August 2006)

Manual Therapy Journal - Volume 13, Issue 4, Pages 277-372 (August 2008)

Manual Therapy Journal - Volume 14, Issue 4, Pages 353-460 (August 2009)

Manual Therapy Journal - Volume 13, Issue 3, Pages 181-276 (June 2008)

Manual Therapy Journal - Volume 14, Issue 3, Pages 241-352 (June 2009)

Manual Therapy Journal - Volume 14, Issue 2, Pages 117-240 (April 2009)

Manual Therapy Journal - Volume 13, Issue 2, Pages 91-180 (April 2008)

Manual Therapy Journal - Volume 14, Issue 5, Pages 461-584 (October 2009)

Manual Therapy Journal - Volume 8, Issue 2, Pages 63-128 (May 2003)

Manual Therapy Journal - Volume 12, Issue 4, Pages 297-396 (November 2007)

Manual Therapy Journal - Volume 8, Issue 1, Pages 1-62 (February 2003)

Manual Therapy Journal - Volume 10, Issue 4, Pages 239-304 (November 2005)

Manual Therapy Journal - Volume 8, Issue 4, Pages 193-270 (November 2003)

Manual Therapy Journal - Volume 13, Issue 1, Pages 1-90 (February 2008)

Manual Therapy Journal - Volume 10, Issue 1, Pages 1-92 (February 2005)

Manual Therapy Journal- Volume 13, Issue 6, Pages 475-564 (December 2008)

Manual Therapy Journal - Volume 12, Issue 1, Pages 1-84 (February 2007)

Manual Therapy Journal - Volume 12, Issue 2, Pages 85-198 (May 2007)

Manual Therapy Journal - Volume 10, Issue 2, Pages 93-174 (May 2005)

Manual Therapy Journal - Volume 14, Issue 1, Pages 1-116 (February 2009)

Manual Therapy Journal - Volume 14, Issue 6, Pages 585-716 (December 2009)

Manual Therapy Journal - Volume 11, Issue 1, Pages 1-90 (February 2006)

Manual Therapy Journal - Volume 11, Issue 4, Pages 241-358 (November 2006)

Manual Therapy Journal - Volume 11, Issue 2, Pages 91-166 (May 2006)

Manual Therapy Journal - Volume 9, Issue 3, Pages 123-182 (August 2004)

Manual Therapy Journal - Volume 9, Issue 4, Pages 183-246 (November 2004)

Manual Therapy Journal - Volume 9, Issue 1, Pages 1-58 (February 2004)

Manual Therapy Journal - Volume 9, Issue 2, Pages 59-120 (May 2004)

Manual Therapy Journal - Volume 8, Issue 3, Pages 129-192 (August 2003)

Manual Therapy Journal - Volume 12, Issue 3, Pages 199-296 (August 2007)

Manual Therapy Journal - Volume 10, Issue 3, Pages 175-238 (August 2005)

Manual Therapy Journal - Volume 11, Issue 3, Pages 167-240 (August 2006)

Manual Therapy Journal - Volume 13, Issue 4, Pages 277-372 (August 2008)

Manual Therapy Journal - Volume 14, Issue 4, Pages 353-460 (August 2009)

Manual Therapy Journal - Volume 13, Issue 3, Pages 181-276 (June 2008)

Manual Therapy Journal - Volume 14, Issue 3, Pages 241-352 (June 2009)

Manual Therapy Journal - Volume 14, Issue 2, Pages 117-240 (April 2009)

Manual Therapy Journal - Volume 13, Issue 2, Pages 91-180 (April 2008)

Manual Therapy Journal - Volume 14, Issue 5, Pages 461-584 (October 2009)

Manual Therapy Journal - Volume 8, Issue 2, Pages 63-128 (May 2003)

Manual Therapy Journal - Volume 12, Issue 4, Pages 297-396 (November 2007)

Manual Therapy Journal - Volume 8, Issue 1, Pages 1-62 (February 2003)

Manual Therapy Journal - Volume 10, Issue 4, Pages 239-304 (November 2005)

Manual Therapy Journal - Volume 8, Issue 4, Pages 193-270 (November 2003)

Manual Therapy Journal - Volume 13, Issue 1, Pages 1-90 (February 2008)

Manual Therapy Journal - Volume 10, Issue 1, Pages 1-92 (February 2005)

Manual Therapy Journal- Volume 13, Issue 6, Pages 475-564 (December 2008)

Manual Therapy Journal - Volume 12, Issue 1, Pages 1-84 (February 2007)

Manual Therapy Journal - Volume 12, Issue 2, Pages 85-198 (May 2007)

Manual Therapy Journal - Volume 10, Issue 2, Pages 93-174 (May 2005)

Manual Therapy Journal - Volume 14, Issue 1, Pages 1-116 (February 2009)

Manual Therapy Journal - Volume 14, Issue 6, Pages 585-716 (December 2009)

Manual Therapy Journal - Volume 11, Issue 1, Pages 1-90 (February 2006)

Manual Therapy Journal - Volume 11, Issue 4, Pages 241-358 (November 2006)

Manual Therapy Journal - Volume 11, Issue 2, Pages 91-166 (May 2006)

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