Journal of
Official journal of the: ® Association of
Neuromuscular Therapists, Ireland ® Australian Pilates Method Association ® Hands On Seminars, USA ® National Association of Myofascial Trigger Point Therapists, USA ® Pilates Foundation, UK Volume 15 Number 1 2011
Bodywork and Movement Therapies EDITOR-IN-CHIEF
Leon Chaitow ND, DO
c/o School of Integrated Health, University of Westminster, 115 New Cavendish Street, London W1M 8JS, UK Preferred mailing address: P.O.Box 41, Corfu, Greece 49100 (
[email protected])
ASSOCIATE EDITORS Geoff Bove DC, PhD Kennebunkport, ME, USA (
[email protected]) John Hannon DC San Luis Obispo, CA, USA (
[email protected]) Glenn M. Hymel EdD, LMT Department of Psychology, Loyola University, New Orleans, LA, USA (
[email protected])
Dimitrios Kostopoulos PhD, DSc, PT Hands-on Physical Therapy, New York, NY, USA (
[email protected]) Craig Liebenson DC Los Angeles, CA, USA (
[email protected])
ASSOCIATE EDITORS: PREVENTION & REHABILITATION Warrick McNeill MCSP London, UK (
[email protected])
Matt Wallden MSc, Ost, Med, DO, ND London, UK (
[email protected]) International Advisory Board
D. Beales MD (Cirencester, UK) C. Bron PT (Groningen, The Netherlands) I. Burman LMT (Miami, FL, USA) J. Carleton PhD (New York, USA) F. P. Carpes PhD (Uruguaiana, RS, Brazil) Z. Comeaux DO FAAO (Lewisburg, WV, USA) P. Davies PhD (London, UK) J. P. (Walker) DeLany LMT (St Petersburg, FL, USA) M. Diego PhD (Florida, USA) J. Dommerholt PT, MS, DPT, DAAPM (Bethesda, MD, USA) J. Downes DC (Marietta, GA, USA) C. Fernandez de las Peñas PT, DO, PhD (Madrid, Spain) T. M. Field PhD (Miami, FL, USA) P. Finch PhD (Toronto, ON, Canada) T. Findley MD, PhD (New Jersey, USA) D. D. FitzGerald DIP ENG, MISCP, MCSP (Dublin, Ireland) S. Fritz LMT (Lapeer, MI, USA)
G. Fryer PhD. BSc., (Osteopath), ND (Melbourne City, Australia) C. Gilbert PhD (San Francisco, USA) C. H. Goldsmith PhD (Hamilton, ON, Canada) S. Goossen BA LMT CMTPT (Jacksonville, FL, USA) S. Gracovetsky PhD (Ocracoke, NC, USA) M. Hernandez-Reif PhD (Tuscaloosa, AL, USA) P. Hodges BPhty, PhD, MedDr (Brisbane, Australia) B. Ingram-Rice OTRLMT (Sarasota, FL, USA) J. Kahn PhD (Burlington, VT, USA) R. Lardner PT (Chicago, IL, USA) P. J. M. Latey APMA (Sydney, Australia) E. Lederman DO PhD (London, UK) D. Lee BSR, FCAMT, CGIMS (Canada) D. Lewis ND (Seattle, WA, USA) W. W. Lowe LMT (Bend, OR, USA) J. McEvoy PT MSC DPT MISCP MCSP (Limerick, Ireland) L. McLaughlin DSc PT (Ontario, Canada) C. McMakin MA DC (Portland, OR, USA) J. M. McPartland DO (Middleburg, VT, USA)
C. Moyer PhD (Menomonie, WI, USA) D. R. Murphy DC (Providence, RI, USA) T. Myers (Walpole, ME, USA) C. Norris MSc CBA MCSP SRP (Sale, UK) N. Osborne BSc DC FCC (Orth.), FRSH, ILTM (Bournemouth, UK) B. O’Neill MD (North Wales, PA, USA) J. L. Oschman PhD (Dover, NH, USA) D. Peters MB CHB DO (London, UK) M. M. Reinold PT, DPT, ATC, CSCS (Boston, MA, MD, USA) G. Rich PhD (Juneau, AK, USA) C. Rosenholtz MA, RMT (Boulder, CO, USA) R. Schleip MA, PT (Munich, Germany) J. Sharkey MSc, NMT (Dublin, Ireland) D. Thompson LMP (Seattle, WA, USA) C. Traole MCSP, SRP, MAACP (London, UK) P. W. Tunnell DC, DACRB (Ridgefield, CT, USA) E. Wilson BA MCSP SRP (York, UK) A. Vleeming PhD (Rotterdam, The Netherlands)
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Journal of Bodywork & Movement Therapies (2011) 15, 1e2
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EDITORIAL
Learning about fascia When I was reminded that the 3rd Fascia Conference is just over a year away (March 2012), I reflected on just how much we now know about fascial structure and function e as well as on the large gaps in our knowledge, that remain. Hopefully many of these gaps will be filled when this gathering takes place next year. When I was studying osteopathy, many years ago, fascia entered into the lessons and lectures as a somewhat mysterious (and seemingly unimportant in clinical terms) part of the economy of the body. Certainly it featured large in the historical aspects of osteopathy’s evolution, with early pioneers referring to its all-pervading nature. Fascia was everywhere, and there were theories and assertions as to its relevance, but there was a very little that was rooted in science. (Still, 1902) So, the question remained e what did fascia do? What was fascia for? As my studies progressed, and as the years went by, it became ever clearer that fascia was not just a background material, with little function apart from its obvious supporting role, but rather a widespread, tenacious, connective tissue involved deeply in almost all of the fundamental processes of the body’s structure, function and metabolism. For example, in therapeutic terms, as well as anatomically, there is little logic in trying to consider muscles and joints as separate structures from fascia, because they are so intimately related. Remove connective tissue from the scene and any muscle left would be a jelly-like structure without form or functional ability, and joints would quite simply fall apart. We also now know that there exists a tensegrity-like state of structural and functional continuity between all of the body’s hard and soft tissues, with fascia being the ubiquitous elastic e plastic, gluey, component that invests, supports and separates, connects and divides, wraps and gives cohesion, to the rest of the body e the fascial, connective tissue network. Any tendency to think of a local dysfunction, as existing in isolation should be discouraged as we try to visualize a complex, interrelated, symbiotically functioning assortment of tissues, comprising skin, muscles, ligaments, tendons and bone, as well as the neural structures, blood and lymph channels, and vessels that bisect and invest these 1360-8592/$36 ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.10.002
tissues e all given shape, form and functional ability by the fascia (Schleip et al., 2006; Ingber, 2008; Solomonow, 2009; Myers, 2009). And what has emerged from the first two Fascia conferences e Boston 2007 and Amsterdam 2009 e suggests that there is far more to learn. These conferences brought clinicians of all schools, together with scientific researchers, in the hope and expectation that this would lead to a cross-fertilization, in which the clinical needs, confusions and questions of practitioners and therapists would inform researchers, who in turn would help clinicians to better understand the real nature of fascia in relation to their therapeutic efforts. It was further hoped that researchers would be spurred to new directions of study of fascia. And this has happened, and continues, with studies emerging at a remarkable pace, that have clarified the nature and multiple functions and roles of fascia in the body e many of these being reported or published in JBMT e for example the studies by Standley and Meltzer (2008). JBMT has been a supporter of the two previous Fascia Research Conferences, and will actively support the 3rd Fascia Research Congress e that will take place in Vancouver, Canada between 28th and 30th, 2012. The theme of the 3rd congress will be: What Do We Know? What Do We Notice? Continuing the Scientist/Clinician Dialogue The conference proper will be preceded (March 23e27) by a Fascial Dissection Workshop, with a range of additional pre and post-conference workshops, on March 27th and March 31st. At this early stage the planning for the Vancouver conference is already advanced. For example, among the confirmed keynote speakers (note that the topics listed alongside the names are tentative at this stage) are: Cesar Fernandez de las Penas DO PhD: Myofascial Pain Al Banes PhD: Mechanical loading and fascial changes e tendon focus Karen Sherman PhD: Existing trials on fascia in the context of manual therapies
2
Editorial Carla Stecco MD: Fascial anatomy overview Dr. Rolf K. Reed: Fluid dynamics (lymph, circulation etc) Mary Francis Barbe PhD: Changes in fascia related to repetitive motion disorders
A number of panel sessions are also in the planning stage that will highlight the needs and interests of all clinicians. The conference website is http://www.fasciacongress. org/2012/. There has been a call for Abstracts e and guidelines are to be found on the website. As the organising committee have said “The 2012 Fascia Congress will centre on the latest and best research on human fasciae. Additionally‑and recognizing the interests of clinicians in gaining insights that will bear on practical applications‑the program will be designed to include more presentation time to relating the research findings to clinical issues.” JBMT will carry regularly updated advertisements for the Vancouver event, and intends to publish review papers on their keynote topics, by a number of presenters.
References Ingber, D., 2008. Tensegrity and mechanotransduction. Journal of Bodywork and Movement Therapies 12 (3), 198e200. Myers, T., 2009. Anatomy Trains, second ed. Churchill Livingstone, Edinburgh. Schleip, R., Naylor, I., Ursu, D., et al., 2006. Passive muscle stiffness may be influenced by active contractility of intramuscular connective tissue. Medical Hypotheses 66 (1), 71. Solomonow, M., 2009. Ligaments: a source of musculoskeletal disorders. Journal of Bodywork and Movement Therapies 13 (2), 136e154. Standley, P.R., Meltzer, K.R., 2008. In vitro modelling of repetitive motion strain and manual medicine treatments: potential roles for pro- and anti-inflammatory cytokines. Journal of Bodywork and Movement Therapies 12, 201e203. Still, A.T., 1902. Philosophy and Mechanical Principles of Osteopathy. Hudson-Kimberly Pub. Co., Kansas City, MO.
Leon Chaitow, N.D., D.O. 144 Harley Street, London W1G 7LE, United Kingdom E-mail address:
[email protected] Journal of Bodywork & Movement Therapies (2011) 15, 3e14
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journal homepage: www.elsevier.com/jbmt
Does massage therapy reduce cortisol? A comprehensive quantitative review Christopher A. Moyer, Ph.D*, Lacey Seefeldt, B.A., Eric S. Mann, B.A., Lauren M. Jackley, undergraduate senior University of Wisconsin-Stout, USA Received 15 March 2010; received in revised form 22 May 2010; accepted 31 May 2010
KEYWORDS Massage; Cortisol; Anxiety; Depression; Pain; Effect size; Randomized controlled trial
Summary Objectives: It is frequently asserted that massage therapy (MT) reduces cortisol levels, and that this mechanism is the cause of MT benefits including relief from anxiety, depression, and pain, but reviews of MT research are not in agreement on the existence or magnitude of such a cortisol reduction effect, or the likelihood that it plays such a causative role. A definitive quantitative review of MT’s effect on cortisol would be of value to MT research and practice. Methods: After first performing a comprehensive literature search and retrieval, we use rigorous and conventional meta-analytic methods for calculating between-groups effect sizes. As a point of comparison, we also replicate an unconventional approach taken by other reviewers, in which MT recipients’ within-group cortisol reductions are quantified as a percentage of change, despite the fact that this introduces numerous confounds not addressed by the first approach. Results: Resultant between-groups effect sizes are almost all small (ds Z 0.05e0.30) and nonsignificant. The lone exception is MT’s multiple-dose effect in children, which is larger (d Z 0.52) and statistically significant, but which is based on only three studies and vulnerable to the file-drawer threat. Within-group percentage reductions of cortisol in MT recipients are generally smaller than those found by other reviewers, and are generally inconsistent with the more rigorous between-groups results, which illustrates the unsuitability of this unconventional approach to assessment of treatment effects. Conclusions: MT’s effect on cortisol is generally very small and, in most cases, not statistically distinguishable from zero. As such, it cannot be the cause of MT’s well-established and statistically larger beneficial effects on anxiety, depression, and pain. We conclude that other causal mechanisms, which are still to be identified, must be responsible for MT’s clinical benefits. ª 2010 Elsevier Ltd. All rights reserved.
* Corresponding author at: Psychology, 307 McCalmont Hall, University of Wisconsin-Stout, Menomonie, WI 54751, USA. Tel.: þ1 715 232 1621; fax: þ1 715 232 5303. E-mail address:
[email protected] (C.A. Moyer). 1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.06.001
4
C.A. Moyer et al.
Massage therapy (MT), the manual manipulation of soft tissue to promote health and wellness, has several beneficial effects validated by research. Researchers generally agree that MT can lessen the pain associated with some specific conditions (e.g., low back pain, Furlan et al., 2008; arthritis, Beider and Moyer, 2007) and reduce anxiety and depression (Moyer et al., 2004; Field, 1998). Some evidence also suggests that MT may promote weight gain in premature infants (Field, 1998; Field et al., 2007; Scafidi et al., 1990), though more evidence is needed to establish cost-effectiveness (Vickers et al., 2004). But despite the general consensus for these MT effects, there is much less consensus on their underlying causal mechanisms. This is especially true for the assertion that MT reduces bodily levels of cortisol, a hormone regulated by the hypothalamic-pituitary-adrenocortical axis that is associated with psychological, physiological, and physical health functioning. The possibility that MT’s clinical benefits are brought about by the treatment’s ability to reduce cortisol is frequently reported as established fact in the research literature (e.g., Field et al., 2005; Field, 1998), in the popular press (e.g., Lewis, 2007; Ehrenfeld, 2008; Gupta, 2008; Westlake, 2009; Yorio, 2009), and by professional MT organizations (e.g., American Massage Therapy Association, 2009), even though this assertion is contentious. Six previous reviews have examined MT’s effect on cortisol. These reviews, some narrative and some quantitative, are not in agreement despite the fact they Table 1
draw on many of the same individual studies. We summarize their findings in the following paragraphs and in Table 1.
Field, 1998 This seminal article is the first attempt to comprehensively review MT effects in human recipients of all ages, and the theories that might explain those effects. Studies conducted by Field’s Touch Research Institute (TRI) are emphasized, though some other studies are also included in support of MT’s potential to facilitate growth, reduce pain, increase alertness, reduce depression, and enhance immune function. MT’s effect on human cortisol levels is reported to be consistent across the range of studies reviewed, and is strongly asserted as a precursor to its beneficial effects. The assertion that cortisol reductions underlie MT’s effects in human recipients is offered in conjunction with the observation that massagelike procedures performed on mammalian laboratory animals, especially procedures that apply firm rather than soft pressure, reduce the animals’ stress hormone levels. With regard to human recipients, Field states that firmpressure MT “may increase vagal activity, which in turn lowers physiological arousal and stress hormones (cortisol levels)” (p. 1278). This review is limited by its strictly narrative format, which does not quantify the magnitude, consistency, or statistical significance of the effects it describes, and by its emphasis on the findings of a single laboratory, which leaves open the possibility that other MT studies with contradictory findings have been omitted.
Summary of previous reviews concerned with MT and cortisol reduction.
Review
Participant age range
Quantification of effect
Effect size
Conclusion
Field (1998)
All
None
n/a
"Across studies, decreases were noted in. stress hormones (cortisol)" (p. 1278).
Moyer et al. (2004)
Non-infant
Between-groups standardized mean difference
g Z 0.14 (95% CI Z 0.10, 0.38)
"Cortisol. was not significantly reduced, a finding that contrasts with the conclusion previously reached by Field (1998)" (p. 13).
Field et al. (2005)
All
Within-group percentage of change
31% mean decrease
"Positive changes have been noted in biochemistry following massage therapy including reduced cortisol" (p. 1411).
Beider and Moyer (2007)
Pediatric
Between-groups standardized mean difference
g Z 0.28 (95% CI Z 0.27, 0.84)
"There is currently scant evidence that MT provides benefits by first reducing cortisol, as MT’s effect on this stress hormone is seen to be small when analyzed correctly" (p. 33).
Field et al. (2007)
All
None
n/a
"To date, we can confidently say that stimulating pressure receptors under the skin leads to a cascade of events including. decreasing cortisol" (p. 85).
Moraska et al. (2008)
Adult
None
n/a
"A reduction in salivary cortisol was evident following a single massage treatment, yet salivary cortisol returns to initial values when assessed at a later time point, even if massage therapy was administered during the interim timeframe." (p. 8).
Note. CI Z Confidence interval.
Does massage therapy reduce cortisol?
5
Moyer et al., 2004
Beider and Moyer, 2007
This article is the first wide-ranging meta-analysis of MT effects in human recipients other than infants. The authors conducted a systematic search of the MT research literature, converted the results of randomized controlled trials into standardized mean difference effect sizes that objectively compare the effect of MT against control treatments, and applied a trim and fill procedure (Duval and Tweedie, 2000) to explore the possibility that significant results were influenced by publication bias. These steps improve upon narrative review techniques by producing results that are objective, replicable, and quantifiable. Only seven studies that assessed the effect of MT on cortisol with data sufficient for meta-analysis were located; six of these seven studies were from TRI. Meta-analytic results indicate that MT recipients, on average, had cortisol levels that were only 0.14 standard deviations lower than recipients who had experienced a wait-list condition or a comparison treatment (e.g., engaging in progressive muscle relaxation), a small and nonsignificant (95% CI Z 0.10, 0.38) effect. The authors concluded that cortisol levels were not significantly reduced by MT, and noted that this conclusion differs markedly from that reached by Field (1998).
This review examines several MT effects in pediatric samples. The authors located only two studies that assessed the effect of MT on salivary cortisol with sufficient data to permit effect size calculation. Results indicated that MT recipients, on average, had posttest cortisol levels only 0.28 standard deviations lower than control participants, a small and nonsignificant (95% CI Z 0.27, 0.84) effect that parallels the result for adults in Moyer et al. (2004). In addition, the authors found no evidence of an MT effect on immune system functioning in pediatric participants, an effect that other researchers do claim and ascribe directly to MT’s cortisol reducing effect (Diego et al., 2001). A limitation of this pediatric review is its reliance on a very small number of studies.
Field et al., 2005 This article reviews the effects of MT on biochemistry, including cortisol levels. The authors identify 17 TRI studies that have examined the effect of MT on cortisol, and calculate the average percentage decrease in cortisol levels that were experienced by MT recipients during the treatment period. Combining these, they conclude that MT decreases cortisol levels an average of 31%. Limitations of this review are numerous and include (a) restriction to TRI studies; (b) equal weighting of all studies, despite the fact that they contain different numbers of participants; (c) using percentage of change as the measure of effect, instead of conventional and more rigorous meta-analytic effect sizes; and (d), omitting control group data from studies that randomized participants to both treatment and control groups. Each of these limitations has the potential to bias or invalidate the final conclusion, especially the last two. Total reliance on percentage of change as a measure of effect is potentially misleading, given this form of quantification presumes that zero is a realistic value for cortisol level, when it almost certainly is not. Further, no source that we know of advocates percentage of change as a statistically valid measure of effect. More egregious, however, is the decision to omit control group data from controlled studies. Possibly, the cortisol levels of control group participants decreased a similar amount, which would mean MT had no unique effect on cortisol. Alternately, if control participants’ cortisol levels tended to increase, omitting these data would mean that MT’s effect on cortisol would be significantly underestimated as a result. In addition, eliminating all control group data introduces numerous wellknown threats to validity, including time, spontaneous remission, attention and placebo effects, and regression to the mean. Because all control group data has been omitted from this review, its potential to inform us of the effect of MT on cortisol is extremely limited.
Field et al., 2007 The authors of this narrative review state that it is an update of Field’s 1998 narrative review (1998), and conclude that "we can confidently say that stimulating pressure receptors under the skin leads to a cascade of events including. decreasing cortisol, which may facilitate immune function" (p. 85). The limitations of this review are the same as those discussed in reference to the 1998 narrative review, and no mention of other researchers’ contradictory findings is made.
Moraska et al., 2008 This review examines stress-related physiological adjustments resulting from MT, including cortisol changes. A strength of this review is its systematic literature search. Because the review is not limited to studies that provide sufficient data for effect size calculation, the authors were able to include a larger sample of studies than some previous reviews. They located four studies that assessed only salivary cortisol, five studies that assessed only urinary cortisol, and four studies that assessed cortisol in both these ways. Based on these studies, they conclude that “hormonal variables associated with stress were largely unaffected by multiple massage treatments,” but go on to note that “a reduction in salivary cortisol was evident following a single massage treatment. [however] salivary cortisol returns to initial values when assessed at a later time point, even if massage therapy was administered during the interim timeframe” (p. 8). This review is limited by its dependence on analyses and conclusions presented in the original studies, as opposed to conducting a systematic, quantitative analysis based on the original data. This is problematic because the quality of MT research varies greatly, and it is not unusual for original study authors to perform unsuitable analyses (e.g., pre-post within-group analyses that do not match a study’s between-groups design) and, subsequently, to reach conclusions that are not supported by the data collected (Moyer, 2009). Six reviews, then, which draw on an overlapping set of original studies, reach quite different conclusions. The aim of the current review is to address this controversy by rigorously and comprehensively quantifying the effect of MT on recipients’ cortisol levels. Given the recent and rapid
6 increase in MT research (Moyer et al., 2009), we expect to improve on the number of studies that were able to be included in previous quantitative reviews. Further, we improve on narrative reviews, including the most recent ones, by (a) conducting a wide-ranging literature search to obtain the largest and least-biased possible sample of suitable studies; (b) objectively quantifying effects, as opposed to relying on a narrative format; (c) presenting the results of controlled, between-groups standardized mean difference effect sizes alongside the corresponding withingroup percentage reductions of cortisol that were experienced by MT participants; and (d) transparently reporting whether cortisol was assessed via blood, saliva, or urine.
Methods Operational definition MT can take various forms and can be applied to various anatomical sites. In addition, it is not established that commonly used MT terms (e.g., Swedish) have precise or universally agreed upon meanings. The present review operationalizes MT as the manual manipulation of soft tissue to promote health and wellness. We systematically exclude selfmassage and specific medical interventions (e.g., cardiac massage). Also excluded are combination treatments in which research participants receive MT in conjunction with some other form of treatment other than standard care. Use of lubricating oils or lotions and exposure to music are not considered part of combination treatment when used with MT, as these are commonly part of MT in ordinary practice.
Literature search and inclusion criteria A search concluded on January 6, 2010, using the keywords massage and cortisol, yielded the indicated number of articles in the following databases: CINAHL, 28; Dissertation Abstracts, 5; Google Scholar, 1997; PsycINFO, 168; and PubMed, 86. The abstract of each article was examined to determine possible relevance, and only articles that were clearly irrelevant were discarded, which resulted in an initial database of 173 articles requiring closer inspection. These 173 articles were scrutinized to determine if they (a) examined a treatment that fit our operational definition of MT, (b) provided graphical and/or numerical data on the effect of MT on cortisol levels in human recipients, (c) used random assignment of participants to an MT condition and one or more control conditions, and (d) reported results not duplicated in another retrieved article. This yielded 18 articles, containing 19 studies, that met all three criteria. The following information was then extracted, independently by two different raters, from those 18 articles and entered into a database: publication year, type of MT performed, site to which MT was administered, training of person(s) who administered MT, age of participants, duration of individual MT sessions, number of MT sessions, study duration, type of control(s) used, number of participants receiving MT or control treatment(s), form of cortisol assessment, and all relevant cortisol data. In cases where an article was suitable for inclusion but did not include sufficient data for effect size calculation (e.g., means are
C.A. Moyer et al. provided but standard deviations or standard errors are not), attempts were made to contact article authors to determine if the necessary data was available, but in no case was this effort fruitful.
Study details and data Study coding All data was coded by two raters independently. The lead author (C.A.M.) coded all studies, and three students (L.S., E.S.M., and L.M.J.) who received prior training from the lead author each coded a portion of the studies. Agreement rates (AR) were >92% for most categories; lower but acceptable agreement rates were attained for study ns (AR Z 85%) and therapist training (AR Z 82%). Discrepancies were resolved by first checking for coding or data entry errors, which were subsequently corrected. In the smaller number of instances where discrepancies represented a difference in judgment among coders, the first author (C.A.M.) conferred with the other rater before making a final determination. Types of effects MT effects can logically be divided into single-dose effects, which may result from a single session of treatment, and multiple-dose effects, which may result from a series of treatments (Moyer et al., 2004). MT’s effect on cortisol has been researched in both of these ways, sometimes simultaneously, as illustrated by a study of MT for infants of depressed mothers (Field, Grizzle, et al., 1996). In that study, infant subjects were randomly assigned to receive twice-weekly 15-minute sessions of MT, or to be held and rocked in a rocking chair according to the same schedule, across a period of six weeks. Single-dose effects were examined by pretest and posttest assessments of salivary cortisol performed at the first session of MT or rocking. Multiple-dose effects were examined by assessments of urinary cortisol prior to the first session, and following the twelfth and final session, for both groups. In some studies, the single-dose effect is examined twice; once at the first session in a series of treatments, and again at the last session in a series of treatments. This pattern makes it practical to separately examine the single-dose effects of a first session versus those of a last session. Beider and Moyer (2007) discovered that, for pediatric samples, the single-dose effect of a first MT session and those of a last MT session in a series are significantly different for state anxiety; both are effective, but the effect from the last session in a series is significantly larger. This suggests that there may be adaptive processes involved in receiving MT. For this reason, we examine the single-dose cortisol reducing effects of a first MT session in a series, and those of a last MT session in a series, separately. When primary studies administered only a single session of MT, as many do, we treat that single session as a first session in the current review. In all studies we examined, MT’s single-dose effect on cortisol is assessed by means of a blood draw or a saliva sample, both of which are suitable for capturing a shortterm change in cortisol (Lovallo and Thomas, 2000). Occasionally, the multiple-dose effect of MT on cortisol assessed in a specific study could be quantified in at least two ways. Urinary assessment of cortisol is most often used
Does massage therapy reduce cortisol? across a series of treatments, but selective use of salivary assessments taken at the corresponding times might also be used to capture the multiple-dose effect. Using assessments of cortisol in blood and saliva in this way allows inclusion of a greater number of studies to examine the multiple-dose effect in the current review, because there are some studies that administer a series of treatments without assessing urinary cortisol. The decision to proceed in this manner is supported by findings in recent large scale quantitative reviews concerned with cortisol that find no effect related to method of assessment (Meewisse et al., 2007; Michaud et al., 2008). Nevertheless, we include information on the method of cortisol assessment for each individual study and also conduct a separate analysis of multiple-dose effects based only on the results of urinary cortisol assessments. Multiple studies in a single document In all but one case, each MT research document includes a single study. The exception is the study by Olney (2007) in which two different MT treatment groups are included. In this case, we treated those results as separate independent studies in the current review because we wished to retain the unique information provided by two different MT conditions (one which delivers a series of five 10 m sessions of MT, and one which delivers a series of ten 10 m sessions of MT) even though this violates the condition that individual study effect sizes should be statistically independent (Lipsey and Wilson, 2001). We also check the influence of this decision on our results by conducting secondary analyses in which the two study results from Olney (2007) are averaged to yield a single study result. We also attempted to extract the following pieces of information from every study, as presented in Table 2. Exceptions were made when a category did not apply to a particular study. Anatomical site to which MT was applied Studies vary in the anatomical sites to which MT is applied. In some the site for MT is very limited and specific, while in others MT may be applied to the entire body. Based on our familiarity with the individual studies, we settled on the following descriptors: full body, upper body, back, neck and shoulders, feet. MT type We attempted to record information on the type of MT used in each study. However, at the conclusion of coding, we had to acknowledge that the MT terminology and methods of description in use to date are insufficient to yield usable information for this category. Eventually, the recent development and implementation of valid MT taxonomies (e.g., Sherman et al., 2006) may address this problem. Therapist training Most studies report having used a professional massage therapist for provision of treatment, while other studies report having used a layperson with only minimal MT training or provide no information on therapist training. We coded studies for therapist training in three ways; those that clearly used a professional massage therapist, those that used a minimally trained layperson, and those that provided no information on
7 therapist training. In cases where it was difficult to distinguish whether the person providing MT was professionally or minimally trained, we coded the study as having used a person with minimal training. Description of sample This indicates important characteristics of the participants, including clinical conditions. Sample age Almost all studies provide information on the age of participants. Most often this is expressed as a mean, but occasionally a range is provided. This data permits us to calculate results separately for children and adult recipients. In separate analyses, we considered studies in which the mean age of participants was less than 18 years of age to be a study of MT for children. Treatment minutes per dose This is the duration of each individual MT treatment administered in the study. Number of doses This is the number of MT treatments administered to a participant during the course of the study. Study duration This is the interval of time across which multiple MT treatments were administered. This category does not apply to studies that examine the effect of a single MT treatment. Description of control This indicates the form of time-matched treatment or attention that control participants received. MT and control N These are the number of participants who received MT or a control treatment. These groups are exclusive. Method of cortisol assessment This indicates if cortisol levels were assessed in blood, saliva, or urine. Quantification of effect Between-groups comparisons of cortisol levels were converted to Cohen’s d effect size. Cohen’s d, calculated as (Group Mean 1 e Group Mean 2)/pooled standard deviation, estimates the number of standard deviations by which the average member of a treatment group differs from the average member of a control group for a given outcome. Individual study effect sizes were subjected to a correction for small sample bias, then weighted by their inverse variance and averaged to generate a mean effect size for each outcome variable. Positive values represent a more desirable effect (i.e., a lower cortisol level) for participants who received MT. Homogeneity analyses were performed on each mean effect size by calculation of the Q statistic, to determine if the dispersion of the individual effect sizes around their mean is greater than that expected due to sampling error alone (Lipsey and Wilson, 2001). Statistical significance of the mean effect sizes was assessed by
8
Table 2
Individual study details.
Study
Site Train? Sample
Age
Mns/ #sess Pd sess
Ctrl
Ns
Arroyo-Morales et al. (2009)
FB
e
University students completing Wingate tests
21 yrs
40
1
Chin (1999)
B
e
Gynecologic surgery patients
42 yrs
10
Ditzen et al. (2007)
NS
e
Heterosexual partnered women
26 yrs
Field, Grizzle, et al. (1996)
FB
e
Infants of depressed mothers
Field, Ironson, et al. (1996) Field et al. (1997)
UB
Y
FB
Field et al. (2009)
Cort Between-groups Effect Sizes (d ) MT Ctrl asmt SD, first SD, last MD
e
Sham electrotherapy
32
2
2d
Attn
10
1
e
Attn (n Z 22), no treatment (n Z 25)
39w
15
12
Medical staff
26 yrs
15
N
Children with juvenile rheumatoid arthritis
10 yrs
FB
Y
Depressed pregnant women
Hernandez-Reif et al. (2000)
FB
Y
Hernandez-Reif et al. (2001)
FB
Hernandez-Reif et al. (2002)
0.13
e
e
34a 29b
B
0.13
0.00
0.00
20
47
S
0.11
e
e
6w
Held þ Rocking 20
20
S, U
0.20
e
0.82
10
5w
PMR
26
24
S
0.72
0.18
0.18
15
30
30d RT
10
10
S
0.70
0.55
0.55
25 yrs
20
6
6w
SC
22
21
S
e
0.18
0.18
Hypertensive adults
52 yrs
30
10
5w
PMR
15
15
S, U
0.00
0.35
0.35
Y
Adults with low back pain
40 yrs
30
10
5w
RT
12
12
U
e
e
0.38
FB
Y
Parkinson’s patients
58 yrs
30
10
5w
PMR
8
8
U
e
e
0.41
Hernandez-Reif et al. (2004)
FB
Y
Postsurgery breast cancer patients
53 yrs
30
15
5w
SC
18
16
U
e
e
0.08
Khilnani et al. (2003)
FB
Y
Children and adolescents with ADHD
13 yrs
20
9
4w
WL
15
15
S
0.00
0.14
0.14
Leivadi et al. (1999)
UB
Y
Female university dance students
20 yrs
30
10
5w
RT
15
15
S
0.15
0.11
0.11
Mackereth et al. (2009) F
e
Multiple sclerosis patients
50 yrs
40
6
6w
PMR
25
25
U
0.04
0.00
0.00
McVicar et al. (2007)
F
e
Healthy individuals
16e59 yrs 60
1
e
Attn
10
10
S
0.17
e
e
Menard (1995)
FB
Y
Gynecologic oncology patients 52 yrs
45
5
5d
SC
15
15
U
e
e
0.74
Olney (2007)
B
Y
Hypertensive and prehypertensive adults
10
5
2w
RT
13
14
S
e
e
0.24
49 yrs
C.A. Moyer et al.
S
28
Note. Dashes indicate that data were not reported, are not relevant, or could not be calculated. Site Z Anatomical site to which massage therapy was applied; FB Z Full body; B Z Back; NS Z Neck and shoulders; UB Z Upper body; F Z Feet. Train? Z Use of professionally trained massage therapist; Y Z Yes; N Z No. Mns/sess Z Length, in minutes, of individual massage therapy and control sessions. #sess Z Total number of massage therapy and control sessions administered. Pd Z Time period across which multiple sessions of treatment were distributed. Cort asmt Z Method of cortisol assessment; B Z In blood; S Z In saliva; U Z In urine. SD Z Single-dose; MD Z Multiple-dose; d Z Days; w Z Weeks; m Z Months; SC Z Standard care; Attn Z Attention; RT Z Relaxation therapy; PMR Z Progressive muscle relaxation. ADHD Z Attention-deficit hyperactivity disorder. Ns in italics indicate the original study reported only total N, and in these cases we assumed even distribution among massage therapy and control groups. a Zthis N was only 31 at the last session of massage therapy. b Zthis N was only 23 at the last control session. Effect sizes are recorded such that positive values indicate a lower level of cortisol for the massage therapy group compared to controls.
0.16 e e U 3 Y Taylor et al. (2003)
FB
Abdominal postsurgery women 56 yrs
45
3d
SC
34
36
e e 10 Y Olney (2007)
B
Hypertensive and prehypertensive adults
49 yrs
10
4w
RT
15
14
S
0.11
Does massage therapy reduce cortisol?
9 calculating the 95% confidence interval (CI) for the population parameter. A significance level of 0.05 or better is inferred when zero is not contained within the CI. A random-effects model was used for the calculation of all between-groups mean effects. As a supplement to the calculation of between-groups effects, and based on the same set of studies, we also present the within-group percentage-point reduction in cortisol level exhibited by MT recipients, which replicates the unconventional approach used in Field et al. (2005). This is calculated as (pretest cortisol value e posttest cortisol value)/pretest cortisol value, corresponding to the time interval of interest. Individual study’s percentage-point reductions were then weighted by study size (N of MT recipients) and averaged to yield mean percentage-point reductions.
Results Table 2 summarizes 19 studies, extracted from 18 reports, that provide quantifiable between-groups data on MT’s cortisol effect. The present dataset comprises 704 individuals (614 adults), 359 of whom were randomized to an MT condition (including 314 adults). As predicted, this is considerably more (over two-and-a-half times as many studies, and participants) than were able to be included in a quantitative analysis of cortisol effects published in 2004 (Moyer et al., 2004). The average session length for MT, across all participants in the current dataset, was 26 and-ahalf minutes (range 10e60 m). Table 3 summarizes all of the following between-groups effects as well as the supplementary analysis of withingroup percentage-point reductions of cortisol exhibited by MT recipients.
Between-groups effect sizes Single-dose, first session There were 460 participants across eleven studies who were randomly assigned to receive either a single-dose of MT that could be considered the first in a series of treatments, or a time-matched control treatment. Comparison of MT versus control posttest values indicates that MT did not reduce cortisol significantly more than control treatments (d Z 0.15, 95% CI Z 0.04, 0.34). These results are displayed graphically in Figure 1. Examined separately, children’s (N Z 90) and adults’ (N Z 370) effect sizes were also both nonsignificant (d Z 0.23, 95% CI Z 0.19, 0.65; and d Z 0.13, 95% CI Z 0.08, 0.34, respectively). Homogeneity analyses for all three of these effects were nonsignificant (all three ps > 0.49), which suggests there is no more variability around these effects than that expected from sampling error. Single-dose, last session There were 307 participants across eight studies who were randomly assigned to receive either a single-dose of MT that could be considered the last in a series of treatments, or a time-matched control treatment. Comparison of MT versus control posttest values indicates that MT did not reduce cortisol more than control treatments (d Z 0.15, 95% CI Z 0.08, 0.37). These results are displayed graphically in Figure 2.
10
C.A. Moyer et al.
Table 3
Mean cortisol reductions across massage therapy studies. Between-groups effect sizes
Within-group reductions for MT
d
95% CI
N
Study entries
Single-dose, first in series Children Adults
0.15 0.23 0.13
0.04, 0.34 0.19, 0.65 0.08, 0.34
460 90 370
11 3 8
7.12 1.41 5.51
12.8 20.7 10.8
Single-dose, last in series Children Adults
0.15 0.30 0.12
0.08, 0.37 0.27, 0.87 0.13, 0.37
307 50 257
8 2 6
1.67 0.48 0.86
18.6 18.5 18.6
Multiple-dose Children Adults
0.12 0.52a 0.05
0.05, 0.28 0.09, 0.95 0.13, 0.22
598 90 508
16 3 13
13.84 1.88 7.88
22.1 35.0 19.8
a
Q
%
p < 0.05.
Examined separately, children’s (N Z 50) and adults’ (N Z 257) effect sizes were also both nonsignificant (d Z 0.30, 95% CI Z 0.27, 0.87; and d Z 0.12, 95% CI Z 0.13, 0.37, respectively). Homogeneity analyses for these three mean effects were nonsignificant (all three ps > 0.49), which suggests there is no more variability around these effects than that expected from sampling error. Multiple-dose There were 598 participants across sixteen studies who were randomly assigned to receive either a multiple-dose
Figure 1
series of MT treatments or a time-matched control treatment. Comparison of MT versus control posttest values indicates that, across all participants, MT did not reduce cortisol more than control treatments (d Z 0.12, 95% CI Z 0.05, 0.28). These results are displayed graphically in Figure 3. Averaging the results of the two studies contained in Olney (2007) as a single study, as opposed to treating them as statistically independent studies, has little influence on this result (d Z 0.13, 95% CI Z 0.04, 0.29). We also conducted a supplementary analysis of multipledose effects based only on the results of urinary cortisol
Single-dose, first in series effect sizes and 95% confidence intervals.
Does massage therapy reduce cortisol?
Figure 2
11
Single-dose, last in series effect sizes and 95% confidence intervals.
assessments. The result from this smaller subset of six studies and 249 participants is essentially the same mean effect bracketed by a wider confidence interval (d Z 0.15, 95% CI Z 0.11, 0.41). When multiple-dose effects are examined individually according to the age range of participants, results diverge. The result for adults (N Z 508) is very small and nonsignificant regardless of whether the results from Olney (2007) are treated as two independent studies (d Z 0.05, 95% CI Z 0.13, 0.22) or averaged as a single study (d Z 0.06, 95% CI Z 0.12, 0.23). In contrast, children’s (N Z 90) cortisol was reduced significantly more by multiple doses of MT than by control treatments (d Z 0.52, 95% CI Z 0.09, 0.95, p < 0.05). Homogeneity analyses for all three multiple-dose effects were nonsignificant (all three ps > 0.39), which suggests there is no more variability around these effects than that expected from sampling error.
Within-group percentage reductions of cortisol exhibited by MT participants Though we do not wish to emphasize them as our primary findings, we also calculated the within-group effect on cortisol evidenced by massage therapy participants, expressed as percentage-point reductions. Our motivation for doing this was to permit direct comparisons with the results of Field et al. (2005), and with the current betweengroups results. MT recipients in these between-groups studies exhibit mean reductions of cortisol that range from 10.8% (single-dose reduction from a first treatment in adults) to 35.0% (multiple-dose reduction in children). Eight of these nine means are lower than the 31% mean cortisol reduction reported by Field et al. (2005), a difference that
is probably attributable to using an overlapping but not identical set of studies, and to our decision to weight these reductions by sample size prior to averaging. There are numerous discrepancies between the between-groups and within-group results. For example, most of the within-group reductions cluster near a 20% reduction (six of them are between 18.5% and 22.1%), but the corresponding between-groups effects for these studies exhibit a six-fold range (d Z 0.05e0.30). Further, the correlations between individual studies’ between-groups effect sizes and their within-group percentage-point reductions do not attain values indicative of good reliability (r Z 0.42 for single-dose, first session; r Z 0.25 for singledose, last session; r Z 0.73 for multiple-dose). Because the meta-analytic procedures for calculating standardized mean effects such as d have been widely used and refined, and are recommended by many methodologists (Lipsey and Wilson, 2001; Hunter and Schmidt, 2004; Rosenthal, 1998), and also because quantifying treatment effects only from the treatment group data collected in controlled trials introduces numerous well-known confounds (e.g., time, spontaneous remission, attention and placebo effects, and regression to the mean), we conclude that the general lack of correspondence between the between-groups and within-group effects demonstrates the latter’s unsuitability as an index of treatment effectiveness.
Discussion The assertion that MT significantly reduces cortisol levels is refuted by the results of this review. These results are highly consistent with the results of prior quantitative reviews, and the methods by which they have been reached
12
C.A. Moyer et al.
Figure 3
Multiple-dose effect sizes and 95% confidence intervals.
are transparent and much less prone to bias than those of narrative reviews. As such, we confidently recommend that the current results, and the conclusions to which they lead, should replace those reached in narrative reviews concerned with the effect of MT on cortisol. MT’s mean effect on cortisol is very small and, in most cases, not statistically distinguishable from zero. The exception to this is the multiple-dose effect of MT on the cortisol levels of children. This effect does reach statistical significance, though we hasten to add that it is based on a very small number of studies and participants, and so is vulnerable to the file-drawer threat (the likelihood that even a small number of relevant but unpublished, and therefore irretrievable, studies with null findings are languishing in the desk drawers of the researchers who conducted them). In addition, this effect combines the results of an infant study (mean subject age 39 weeks) with those of two studies on
more developed children (mean participant ages 10 and 13 years), and the effect contributed by the infant study is the largest by a considerable margin. It is possible that MTs effect on the cortisol levels of infants is distinct from its effect on other age populations, but currently available data do not permit this possibility to be examined further. The results of studies conducted with adults, on the other hand, are based on larger numbers of studies and participants, are highly uniform, and have reasonably narrow confidence intervals. In addition, the homogeneity analyses for these effects indicate that there is no more variability among the individual study effects than that expected from sampling error, which gives little reason to believe that some sizable cortisol reduction associated with MT performed for a certain duration, in a certain way, to a certain anatomical site, or under certain conditions, is being washed out by other forms of MT that do not reduce cortisol. In other words, the various
Does massage therapy reduce cortisol? forms of MT being combined in these analyses appear to be equally ineffective in reducing cortisol levels. However, it should not be concluded from this that MT is ineffective. MT has already been shown to have some significant and sizable clinical effects, especially for reducing anxiety, which may prove to be its most useful clinical effect and the basis of several of its other effects (Moyer, 2008). Rather, what the results of this review make apparent is that MT cannot be generating its sizable and proven reductions of state and trait anxiety, depression, and some types of pain by first reducing cortisol. Indeed, it is likely that the very small mean effect that MT has on cortisol e in most cases a reduction only 0.15 standard deviations better than control e is a clinically insignificant downstream effect, not the fundamental upstream cause, of MT’s large effect on anxiety.
How does MT actually provide its verified clinical benefits? While this review answers the question “does MT reduce cortisol?’ e to which the answer is “very little, if at all” e in other ways it raises more questions than it answers. If MT does not provide its proven clinical benefits by first impacting the endocrine system in this way, how then does it work? Does it work primarily in one way, perhaps by first reducing anxiety, which carries over to other outcome categories, such as depression and pain, or is there a unique MT mechanism for reducing each of these? Will it be more fruitful to examine the impact of MT on the relatively faster-acting branches of the nervous system, as opposed to the relatively slower-acting endocrine system, to determine the biological underpinnings of MT benefits? Does it make sense to search for uniform biological mechanisms enacted by MT, or will it be necessary to construct explanatory models that emphasize the interaction of biological processes with psychological phenomena and social contexts that are associated with MT? We do not yet know the answers to these questions. But we do know that they need to be researched, and we are concerned that they tend to be ignored when a competing explanation has been repeatedly and overconfidently asserted without supporting evidence, as has been the case with MT and cortisol reduction. We hope that the current review might stimulate other researchers’ interest in the unknown causal mechanisms of MT’s clinical effects, as it has for us.
Funding This project was not supported by any outside funding.
Conflict of interest The authors have no conflict of interests to declare.
Author Note We thank Ralph R. Hoffman, Hong-Youn Kim, Jessica E. Moyer, Rebekah Mroz, Joel Schwartz, and Karen Sinz for their assistance in the completion of this study.
13
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Journal of Bodywork & Movement Therapies (2011) 15, 15e23
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
RANDOMIZED CONTROLLED COMPARATIVE STUDY
The immediate effects of traditional Thai massage on heart rate variability and stress-related parameters in patients with back pain associated with myofascial trigger points Vitsarut Buttagat, B.Sc., M.Sc., PhD candidate a,*, Wichai Eungpinichpong, B.Sc., M.Sc., PhD a, Uraiwon Chatchawan, B.Sc., M.PH., PhD a, Samerduen Kharmwan, MD b a b
Division of Physical Therapy, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand Department of Rehabilitation Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
Received 29 December 2008; received in revised form 13 June 2009; accepted 16 June 2009
KEYWORDS Massage; Traditional Thai massage; Myofascial trigger point; Back pain; Randomized control trial
Summary The purpose of this study was to investigate the immediate effects of traditional Thai massage (TTM) on stress-related parameters including heart rate variability (HRV), anxiety, muscle tension, pain intensity, pressure pain threshold, and body flexibility in patients with back pain associated with myofascial trigger points. Thirty-six patients were randomly allocated to receive a 30-min session of either TTM or control (rest on bed) for one session. Results indicated that TTM was associated with significant increases in HRV (increased total power frequency (TPF) and high frequency (HF)), pressure pain threshold (PPT) and body flexibility (p < 0.05) and significant decreases in self-reported pain intensity, anxiety and muscle tension (p < 0.001). For all outcomes, similar changes were not observed in the control group. The adjusted post-test mean values for TPF, HF, PPT and body flexibility were significantly higher in the TTM group when compared with the control group (p < 0.01) and the values for pain intensity, anxiety and muscle tension were significantly lower. We conclude that TTM can increase HRV and improve stress-related parameters in this patient population. ª 2009 Elsevier Ltd. All rights reserved.
* Corresponding author. Tel./fax: þ66 43 202 085. E-mail address:
[email protected] (V. Buttagat). 1360-8592/$ - see front matter ª 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2009.06.005
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Background Myofascial pain syndrome (MPS) has been defined as musculoskeletal pain arising from one or several hyperirritable spots within the belly of muscle(s) called myofascial trigger points (MTrPs) (Fricton and Awad, 1989). MPS is associated with many musculoskeletal conditions. A Thai study found that MPS was the primary diagnosis in 36% of 431 patients with musculoskeletal disorders (Chaiamnuay et al., 1998) and a study at a pain clinic reported that MPS was cited as the most common cause of pain; occurring in 85% of people with back pain (Fishbain et al., 1986). The pathophysiology of MPS is largely unknown making it difficult to design effective approaches for its treatment, although numerous therapeutic approaches, both pharmological and non-pharmalogical, have been tried with varying success rates. Massage therapy is now one of the most frequently used alternative treatments for back pain (Eisenberg et al., 1998). Traditional Thai massage (TTM) is a form of deep massage with brief sustained pressure on the muscles. Pressure point massage along the body’s hypothesised 10 major energy channels or ‘‘Sen Sib’’ is believed to release blocked energy and to increase awareness and vitality. Gentle stretching of the muscles relieves tension, enhances flexibility, and induces a deep state of tranquility (Tapanya, 1993). The report by Chaithavuthi and Muangsiri (2005) suggests that TTM also increases blood circulation, lowers heart rate, reduces pain, improves the depth of breathing and promotes relaxation. However, controlled studies to support the effectiveness of TTM for the treatment of different conditions are limited (Chatchawan et al., 2005). There is no published research that objectively assesses the physiological changes involved with the reported relaxation response following TTM, which could be done using methods such as evaluation of heart rate variability. Heart rate variability (HRV) is controlled by the autonomic nervous system. Generally, sympathetic nervous system (SNS) activity increases heart rate (decreases HRV) and parasympathetic nervous system (PNS) activity decreases heart rate (increases HRV). Observed HRV is believed to be an indicator of the dynamic interaction and balance between the SNS and the PNS (Terathongkum and Pickler, 2004; Task Force of The European Society of Cardiology and The North American Society of Pacing and Electrophysiology, 1996). There is evidence to suggest that the balance between SNS and PNS is affected by MPS. This is supported by Perry et al. (1989) who report patients with chronic MPS and with arthritis had decreased parasympathetic activity and increased sympathetic activity, and by Delaney et al. (2002) who found that myofascial trigger point massage therapy (MTPT) decreased heart rate, systolic blood pressure and diastolic blood pressure and increased parasympathetic activity. The later study also found a related self-perceived reduction in muscle tension when compared to the baseline. Regional and/or referred pain are characteristic of MPS, which can lead to anxiety and depression and reduced HRV if not effectively treated (Carney et al., 1995; Stauss, 2003; Terathongkum and Pickler, 2004; Tousignant-Laflamme and Marchand, 2006; Hummel and van Dijk, 2006).
V. Buttagat et al. Measurement of HRV to investigate autonomic influence on the cardiovascular system can be done using a simple, sensitive and non-invasive technique. This technique is increasingly being used as a powerful predictor of hypertension in patients (Terathongkum and Pickler, 2004; Delaney et al., 2002). One of the conventional methods for analyzing HRV is the frequency domain method that uses spectral analysis to quantify the frequency content of the ECG signals. This analysis has been used to determine the total power frequency and power of high and low frequencies, data that can then be used to determine the contribution of the sympathetic and parasympathetic nervous system to the variability in heart rate. It is generally accepted that vagal activity is the major contributor to the high frequency (HF) component of the spectral analysis, thus an increase in HF power (as well as an increase in total power) reflects increased parasympathetic activity. Interpretation of increased LF power is still unclear and depends to some extent on the unit of measure used. An increase in absolute value of power (ms2) of the LF component may reflect both sympathetic and parasympathetic activity. The LF/HF ratio is considered to be an index of sympathetic/vagal balance with an increase in the ratio suggesting either an increase in sympathetic cardiac modulation or a decrease in parasympathetic modulation, or both (Task Force of The European Society of Cardiology and The North American Society of Pacing and Electrophysiology, 1996; Terathongkum and Pickler, 2004). HRV analysis has also been used to evaluate changes in sympathovagal tone during various emotional states (such as stress and anxiety) and pain (Carney et al., 1995; Stauss, 2003; Terathongkum and Pickler, 2004; TousignantLaflamme and Marchand, 2006; Hummel and van Dijk, 2006). Current literature suggests that the relaxation response, meditation, prayer, yoga and therapeutic touch have each been associated with physiologic changes indicating decreased emotional stress and increased parasympathetic activity, which were measurable by HRV (Terathongkum and Pickler, 2004; Benson et al., 1974). In addition, Diego et al. (2005) reported that massage therapy increased the cardiac vagal index (CVI), vagal tone, gastric motility and decreased tachygastria in a group of preterm neonates when compared with sham massage in a control group. Given the value of HRV as a measure of PNS activity and the lack of evidence about the effect of TTM on the autonomic nervous system we investigated the effects of TTM on HRV and other stress-related parameters in patients with back pain associated with MTrPs.
Methods Design and setting A randomized control trial was conducted in the Division of Physical Therapy, Faculty of Associated Medical Sciences, Khon Kaen University, Thailand. The study was approved by the ethical committee of Khon Kaen University.
Thai massage in patients with back pain
Participants Patients with back pain associated with MTrPs were recruited from Khon Kaen province using bulletin boards and oral requests for participants during a 7-month period between September 2007 and March 2008. The clinical criteria for the diagnosis of MTrPs in this study were adapted from those specified by Travell and Simons (1983). Participants were included if they presented with chronic back pain, which had lasted longer than 12 weeks, and had at least one trigger point in the upper and/or lower back region. Trigger points were diagnosed as the presence of spot tenderness in areas that the patient identified as painful. The criteria for exclusion from the study was based on any history of disease or other disorder, which may affect heart rate variability (HRV); such as myocardial infarction, hypertension, neuropathy diabetes mellitus, fever, a history of acute trauma, spinal fracture, inflammatory arthritis (rheumatoid arthritis or gout), muscle diseases, evidence of neurological deficits, and/or skin diseases. Each patient signed an informed consent form prior to the baseline examination. Estimation of the sample size was based on a pilot study (n Z 7) that compared the immediate effect of TTM (four patients) with that of control treatment (three patients) for subjects with back pain associated with MTrPs. Based on data of the pilot study, a standard deviation (of HF power) of 919.7 was used to calculate the sample size needed to detect a 866.1 ms2 change in HF power (based on the post-test mean differences between groups) which was considered as the level to accept clinical significance of the results with 80% power and 5% significance. In addition, a drop-out rate of 20% was allowed for in estimating the total sample size. According to these criteria, 36 patients were recruited.
Procedure Randomization The 36 patients who met the above inclusion criteria were randomly assigned to either the treatment (TTM) group or
17 the control group using block randomized allocation with block sizes of 2, 4, and 6. Groups were assigned using a pre-generated random assignment scheme enclosed in envelopes (STATA Version 9), which resulted in a total of 18 patients per group.
Treatment Treatment group (traditional Thai massage e TTM) Participants received one 30-min session of TTM onto the back muscles while lying in the prone position during the period between 10.00 and 13.00 h on the day of the study. Based on the experience of the first three authors who work as both physiotherapists and massage therapists, plus the outcome of the pilot study, a 30-min session was considered appropriate for an effective impact of massage when confined to the back area only. All TTM in this study was conducted by a well-trained massage therapist, according to the system of royal Thai massage, which applies the theory of ‘‘Sen Sib’’ or the 10 meridian lines. Massage points included in this method are located along two lines and at an additional, single, point along the paravertebral muscles on each side of the spine (Chatchawan et al., 2005). The two lines on the left side of participants are called Ittha and the two lines on the right side of participants are called Pingkhala (Figure 1). The pressing technique employed in TTM uses the body weight of the massage therapist to apply gentle, gradually increasing, pressure through the therapist’s thumb, fingers, or palm. Pressure is applied until the patient starts to feel slight discomfort after which this pressure is maintained for 5e10 s at a time. This sequence can be repeated several times for each massage point (Chatchawan et al., 2005). Control group The control group relaxed by lying prone quietly in the same environment and for the same period of time as the treatment group. After the study period had ended and all data were collected, the control group were offered a session of TTM for their back. The same pre- and posttreatment assessments were conducted on both groups.
Figure 1 The massage points, along the two meridian lines running from thoraco-cervical junction or C7 to posterior superior iliac spine (PSIS).
18 At the end of the study, all participants in both groups were given the opportunity for instruction in a series of back exercises to conduct at home.
V. Buttagat et al. feel confused’, are answered in terms of severity (not at all, a little, somewhat and very much so). The STAI score has a high correlation with stress (r Z 0.93) (Thai version) (Lertluechachai, 1989).
Outcome measures All outcome measures were assessed before and after the TTM and control sessions. Details of outcome measures and how they were assessed is described below. Heart rate variability (HRV) Participants were requested not to eat, drink or smoke for 4 h before the measurements and during the measurement they were asked to refrain from talking, falling asleep, making exaggerated body movements, and/or intentionally altering their respiration. Before HRV measurement, participants rested in a prone position at room temperature (25 C) for 20 min. HRV was assessed before and immediately after the treatment/control period. Analysis was based on a 10 min period of ECG signal acquisition, followed by computerized Fourier analysis of the ECG waves, using the BIOPAC system. Participants were carefully monitored using the BIOPAC Respiratory Transducer SS5LB to ensure there were no significant respiratory pattern changes during the ECG measurement. HRV was then calculated manually using the power spectral analysis method (frequency domain method). The parameters used were set as follows: total power frequency (TPF) (0.00e0.40 Hz), low frequency (LF) power (0.04e0.15 Hz), high frequency (HF) power (0.15e0.40 Hz). The low frequency to high frequency ratio (LF/HF ratio) was calculated based on the outcome of the power spectral analysis. HF power was the main parameter of interest in this study. Pain intensity and muscle tension Pain intensity and muscle tension were assessed using separate 10-cm visual analogue scales (VAS). The intensity of pain and feeling of muscle tension were reported by the participants using numerical analog scales ranging from 0 to 10 on which 0 indicated no pain or no muscle tension, respectively, and 10 indicated the most pain ever and the tensest ever experienced. Reliability of data obtained with these VAS is reported to be high (r Z 0.99) (Scott and Huskisson, 1979), with high construct validity (Wilkie et al., 1990). Pressure pain threshold (PPT) The pressure pain threshold was measured using the pressure algometry technique recommend by Fisher (1986, 1988) and evaluated by Reeves et al. (1986). The participant was asked to signal when he or she began to feel pain or any discomfort, at which point the compression was stopped (Esenyel et al., 2000). Each trigger point was measured three times and the average was taken for analysis. Results of the pressure measurements were expressed in kg/cm2. The precision of measurement was 0.1 kg/cm2. State anxiety inventory (STAI) The state anxiety inventory (Thai version), is a 20-item inventory on how the participant feels at the moment. Characteristic items, which include ‘I feel at ease’ and ‘I
Body flexibility A sit-and-reach box was used to measure body flexibility. Body flexibility was measured three times and the average was computed for inclusion in the analysis reported here. Reliability of data obtained with the sit-and-reach box is reported to be high (r Z 0.97) (Chatchawan, 2005).
Statistical analyses Data were analyzed using STATA Version 9. Descriptive statistics were used to describe the continuous and categorical data including number of participants, age, weight, sex, etc. Mean and standard deviations of the values were calculated for each variable. Paired t-tests were used to compare outcome variables at baseline with outcome measures immediately after the treatment or control period within each respective group. An analysis of covariance (ANCOVA) was used to compare the difference in post-test values between the control and treatment groups after adjusting for differences in baseline values, for each outcome measure. A difference at the level of p < 0.05 was considered statistically significant.
Results Demographic and baseline clinical characteristic Demographic data and baseline clinical characteristics of the patients are presented in Table 1. Of the 36 patients enrolled in this study, 20 were female and 16 were male. Their mean age was 22.6 2.9 years. Eighty-three percent of the patients were students. In more than 88% of all cases, the most painful trigger point of each patient was found in the lower part of the back. Baseline results for HRV and other outcomes measured pre- and post-treatment are shown in Table 2. Most baseline characteristics were equally balanced between the two groups except that the TTM group had a higher high frequency (HF) heart rate variability measurement and had greater body flexibility.
Immediate effects of traditional Thai massage on heart rate variability Table 2 shows that immediately after receiving TTM; the TPF, LF power and HF power components of HRV were significantly increased when compared with pre-treatment values (t Z 4.2, p < 0.001; t Z 3.7, p Z 0.002; and t Z 4.7, p < 0.001, respectively) and the LF/HF ratio was significantly decreased (t Z 2.3, p Z 0.032). In contrast, no statistically significant difference was found in the control group except for LF/HF ratio, which increased following the control period. When comparing between the two groups (Table 3), it was found that, after adjustment for baseline levels, the post-test values for TPF and HF power among the TTM group were significantly higher than those found
Thai massage in patients with back pain Table 1
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Demographic and baseline clinical characteristics of patients with back pain associated with MTrP.
Characteristics Number of patients Demographic data Age (years); mean (SD) Gender; n (%) of female Weight (kg); mean (SD) Height (cm); mean (SD) Body mass index; n (%)