Physical Agents in Rehabilitation: From Research to Practice

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Physical Agents in Rehabilitation From Researchto Practice

Physlcal Agents ln Rehabllltatlon From Research to Practice Second Edition

Stichelle H. Cameron, PT, OCS l:est Lecturer l:aCuate Program of PhysicalTherapy j,.:ruel Merritt College I i:uc Rerair

and the natureof the appliedforces.aT Scarsneedlowload, long-duration stretch during the appropriate phasefor permanentchangesto occur Studieshaveshown *rat the applicationof tension duringhealingcausesan increasein censilestrength. and immobilization and stress deprivation reduce tensilestrengthand collagenstructure.The recovery curves for tissue experimentallyimmobilized For bet:ween2 and 4 weeks reveal that these processes cantakemonths to reverse,andreversalis oftennever complete. Eachphaseof the healingresponseis necessary and essentialto the subsequentphase.In the optimal scenario,inflammation is a necessarvaspectof the healingresponse and the [irst srept;ward recovery, seting rhe stagefor the ocherphasesof healing.It repeatedinsults or injury occur,however, a chronic inflammatory response may develop that can adverselyafFectthe outcomeof the healingprocess. Acute inflammatory processescan have one of four outcomes.Iirst, and most beneficial,is the complete resolutionand replacementof the injured tissue with like tissue.Second,and most common,is healing by scarformation.The third is the formation of an abscess.Fourth is the possibility of progressionto chronicinflammation.1o

CHRONIC INFLAMMATION Chronic inflammation is the simultaneousproqression of activeinflammation.tissuedestruccion,-and healing.Chronicinflammationcanarisein oneof two ways. The first follows acute inflammation and can be due to the persistenceof the injurious agent(such asa cumulativetrauma)or to someother interference with the normal healing process.The second is a resultof an immune responseto eitheran alteredhost tissueor a foreign material,such as an implant or a suture,or is t}le resultof an autoimmunediseasesuch asrheumatoidarthritis. The normal acute inflammatory processlasts for no morethan2 weeks.II ir continuesfor morechan4 weeks,it is known as subacute inflammation.3 Chronrc inflammationis inflammationthat lastsformonths or years. The primary cells presentduring chronic inflammation aremononuclearcellsincludinglymphocytes, macrophages, andmonocytes(Iig. 2-15).Occasionally eosinophilsare alsopresent.aB The progressionof the inflammatory responseto a chronicstateis a resultof

O e . PATHOLOGY AND PATIENT PROBLEMS

31

Characteristics / Functions

Leukocyte e

Associatedwith . chronic inflammation . phagocytosts

Lysosome

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e

ibrolyticpathways Regulatescoagulation/f

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Regulateslymphocyteresponse

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Ivlonocytesare convertedto macrophageswhen they emigrate from capillanesinto the tissue spaces

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IC

v' If ic

Associatedwith . chronicintlammation

=

immuneresponse Key cell in humoraland cell-mediated

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Lymphocyte

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Associatedwilh . allergicreactions . parasiticinfectionsand associatedinflammatoryreactrcns

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Eosinophil

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. Not phagocytic . Contarnshistamine,which causes increasedvascular permeabilfy

Basophil

Figute2-15, Cellular components of acute and chronic inflammation.

32

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both immunologicand nonimmunologicfactors.The macrophageis an important sourceof inflammatory a n di m m u n o l o g im c e d i a c oa r sn di s a n i m p o r t a ncro m ponent in the regulationof their actions.The role of eosinophilsis much lessclear,althoughthey are often presentin chronic inflammatory conditions that are causedby allergicreactionsor parasiticinfection.4s Chronic inflammation also results in increased fibroblastproliferation,which in turn increasescollagen production and ultimately increasesscar tissue and adhesionformation. This may lead to a loss of function asthe delicatebalancebetweenootimal tensile strengthand mobility of tbe involvei tissuesis lost.

FACTORS AFFECTING THEHEALING PROCESS A number of factors, either local or systemic, can impact or modify the processesof inflammation and repav (Table 2-A1.Localfactors that can affect wound healing include the type, size, and location of the injury infection, blood supply, and external physical forces.

LocalFactors

awl Tissre Repair

Smallerwounds heal faster than larger wounds, and sursicalincisionsheal faster*ran wounds caused by blunl trauma.l6Softtissueinjuriesover bonestend to adhereto the bony surfaces,preventingcontraction and adequateoppositionof the edgesand delaying healing.l6 lnfection Infection in an injured area is the most problematic local factor that can affect healing.Among the complications of wound healing, S0'/" are due to local infection.ll Infections affect collagen metabolism, reducingcollagenproduction and increasinglysis.49 lnfectionoften preventsor delayshealingand encourgranulauon agesexcessive tissueformation.l6 Vascularsupply The healing of injuries largely dependson the availability of a sufficient vascular supply. Nutrition, oxygen tension, and the inflammatory responseall depend on the microcirculatory system to deliver rheir components.50Decreasedoxygen tension resultingfrom a compromisedblood supplycanresult in the inhibition of fibroblastmigration and collagen slmthesis,leadingto decreasedtensilestrengthof the injured area and increasedsusceptibility to infection.2o

Type, size,andlocation oftheiniury Injurieslocatedin well-vascularized tissue,suchas the scalp,heal fasterthan thosein poorlyvascular- Extefnalforces ized areas.16Injuries in areas of ischemia, such as those that may be caused by arterial obstruction or excessivepressure,heal more slowly.16

h p

2-6 FactorsInfluencing Healing Local

Systemic

Type, size,andlocationofinjury Ag" Infection

Infectionor disease

Vascularsupply

Metabolicstatus

Movement/excessive pressure

Nutrition

Temperaturedeviation

Hormones

Topicalmedications

Medication

Electromagnetic energy

Fever

Retainedforeignbody

Oxygen

The application of physical agents including thermal agents,electromagneticenergy,and mechanical forcesmay also influenceinflammation and healing. Cryotherapy (cold therapy), thermotherapy (heat), therapeutic ultrasound electromagnetic radiation, electricalcurrents,and mechanicaipressurehave all been used by rehabilitation professionalsin an attempt to modify the healingprocess.The impact of thesephysicalagentson tissuehealingis discussedin Section2 of this text, which describeseach type of physicalagent,its effects,and its clinicalapplications. Movement Early movement of a newly injured area may delay healing.Thereforeimmobilization may be usedto aid early healing and repair.However, sinceimmobiliry can result in adhesions and stiffness by altering collagencrossJinkingand elasticiry continuouspassive motion (CPM) with stricdy controlled parameters is often usedto remobilize and restorefunction safelv.)rThe use of CPM in coniunctionwi*r short-

One o PATHOLOGY AND PATIENT PROBLEMS

ied nd ac-

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:erm immobilization, compared to immobilization alone, has been shown to achieve a better func:onal outcome in some studies; however, odrer srudieshave found differencesonly in early rangeof Ir has also been reponedrhar padents =ocion.5753 :iilizing CPM during the inflammatory phaseof soft :ssue healingafter anterior cruciateligament reconjrruction usesignificandylesspain-relievingnarcotics -,:ranpatientsnot usingcPMs4(Fig.2-10.

Factors Systemic Age -\ge is a factor to be consideredbecauseof variations :r healingbetween the pediatric,adult, and geriatric :opulations.In childhood,wound closure occurs :rore rapidly than in adulthood becausethe physio-rgical changesand cumulative sun exposure that -;cur wtth aging can reducethe healingrace.ss A :ecreasein the density and cross-linkingof collagen, '...'hichresultsin reducedtensile strength,decreased :-umbersof mast cells and fibroblasts,and a lower s- 1n" : rre oI epiLne]ializaLion. occursin the elderly.56 :oor organizationof cutaneous vesselsin olderpeo:le alsoadverselyaffectswound healing.

33

leading to a decrease in local blood flow. Neuropathies, which are alsocommon,canincrease the potential for trauma and decreasethe ability of softtissuelesionsto heal. Patientswho are immunocompromised,such as those with acquired immune deficiency syndrome (AIDS) or those taking immunosuppressivedrugs after organtransplantation,are more prone to wound infections becausethey have an inadequateinflammatory response.AIDS alsoaffectsmany other facets of the healing processthrough its impairment of phagocytosis,fibroblast function, and collagensynthesis.59 Problemsinvolving the circulatorysystem,including atherosclerosis, sicklecell disease,and hypertension, can also have an adverse effect on wound healing since inflammation and healing depend on the cardiovascularsystemfor the delivery of components to the local area of injury Decreasedoxygen tension resulting from a reducedblood supply can result in an inhibition of fibroblast migration and a decreasedcollagensynthesis,resulting in decreased tensilestrengthandmakingthe injuredareamore susceptibleto reinjury Wounds with a decreasedblood supplyarealsomore susceptibleto infection.20'60

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ical

LOn,

Disease --.' number of diseasescan affect wound healing ::ther direcdy or indirectly.Ior example,poorly con:ol1eddiabetesmellitus impairs collagensynthesis, r:r.creases the risk of infection due to a dampened and decreases -:rununeresponseJ phagocytosisdue to 58Peripheralvasirerations in leukocytetunction.S0 :.rlar compromiseis alsoprevalentin this population,

I AII an tof dLn rof )ns.

Figure2-16.CIM machine. (Courtesy Thera-l(netics Jompany, Cherry Hill, New Jersey.)

Medications Patientswith injuries or wounds often take medications with systemiceffectsthat alter tissuehealing. Forexample,antibioticscanpreventor fight off infection, which can help to speedhealing but may also havetoxic effectsthat inhibit healing. Corticosteroids,such as prednisoneand dexamethasone,block the inflammatory cascadeearly on by blocking the release of arachidonic acid.61 Corticosteroidshavebeenshown to impair all phases of healingby stabilizingcell membranesand inhibiting the production of prostaglandins.They also decreasethe margination,migration, and accumulation of monocytesat the siteof inflammation.62 They severelyinhibit wound contracture,decreasethe rate of epithelialization,and decreaseahetensilestrength of closed, healed wounds.6366 Corticosteroids that are administeredat the time of injury have a greaterimpact becausedecreasingthe inflammatory responseat this early stagedelayssubsequentphases of healingand increasesthe incidenceof infection. In comparisonwith corticosteroids,nonsteroidal antiinflammatory drugs (NSAIDs)such as ibuprofen are lesslikely to impair healing.They act later in the

34

2 . l la

tnaliol, oud Tis shooringpain They inhibit peripheral pain and inflammation by inhibiting the conversion of arachidonic acid to prostaglandinsby cyclooxygenase;howeveq much X Sharppain lower doses and blood levels are required to NSAIDs reducepain than to reduceinflammation.143 been shown to reduce both spontaneous have Pleasemarkthetype and mechanicallyevoked activity in C and A-delta andlocationof your painon thesepictures fibers in acute and chronic models of joint inflammation. Evidencealso existsthat NSAIDSexert central analgesiceffects at the spinal cord and at the dtalamus.144-148 Front Back A.lthoughNSAIDs have excellentshort- to mediumFigure3-13. Body diagramsfor marking the location and term applicationfor the control of moderatelysevere nature ofpain. pain causedby musculoskeletaldisorders,particularly when the pain is associatedwi*r inflammation, sideeffectscanlimit their long-termuse.The primary long-term complicationof most NSAIDs is gastroinPharmacological Approaches testinal iritation and b1eeding.149,1s0 NSAIDs also cause decreased platelet aggregation and thus Pharmacologicalanalgesicagents control pain by modifying inflammatory mediatorsat the penphery, prolonged bleeding time. They can cause kidney damage, bone maffow suppression, rashes and alteringpain transmissionfrom the periphery to the anorexia,and decreasedrenal blood flow in dehycortex,or alteringthe centralperceptionof pain. The selection of a particular pharmacologicalanalgesic drared natienrs.lsll52 tlsins different NSAIDs togetherincreasesthe risk of sideeffects. agentdependson the causeof the pain, the length of The first NSAID was aspirin.Many other NSAIDs, time the individual is expectedto needthe agent,and the side effectsof the agent.Pharmacological agents such as ibuprofen (Motrin), naproxen sodium (Naprosyn,AJeve),and piroxicam (Feldene),are now may be administeredsystemicallyby mouth or injection, or locally by injection into sffucturessurround- availablebo*r over *re counter (OTC) and by preing the spinal cord or into painful or inflamed areas. scription. The principal advantagesof these newer NSAIDs over aspirin are that some have a longer These different routes of administrationallow conduration of action, allowing lessftequent dosingand centrationof the drug at different sitesof pain transbetter compliance,and some causefewer gastroinmission to optimize the control of symptoms with testinal side effects. However, for most patients, varyingdistributions. aspirin effectively relievespain at considerablyless expense,although with a slighdy higher risk of Systemicanalgesics gastrointestinalbleeding, than the newer NSAIDs. Administration of a systemicanalgesicis usuallythe Recendy, specific cyclooxygenaseq,?e 2 (COX?) primary me*rod of pain management.This type of inhibitor NSAIDs, such as celecoxib (Celebrex) treatmentis easyto administerand inexpensive,and can be an effective and appropdate pain-relieving and rofecoxib (Vioxx), have been developed.Prior NSAIDs inhibited both cyclooxygenasetypes 1 and interventionfor many patients.A wide rangeof analgesic medicationscan be systemicallyadministered 2. CyclooxygenaseLype 1, catalyzesthe production of prostaglandins associated with joint inflamorally or by other routes.Thesemedicationsinclude mation while cyclooxygenaseUtpe 2 catalyzes (NSAIDs), nonsteroidalantiinflammatorydrugs acetproduction tlte of prostaglandinsthat protect the aminophen,opiatesand opioids,andantidepressants.

fuIil,lo.n

60

3 t Pain

effects. They control pain that cannot be relieved by nonnarcotic agents and are most effective when the pain is dull and poorly Tocalized. The side effects of opiates, including nausea, vomiting, sedation, suppiession of cough, gastrointestinal mobility, and respiration, as well as their propensity to causephysicai iependence and depressionwith long-term use, limit their application for the long-term management of drugs. -,s.,rfoik"1eta1 pain. Respiratory depression also limits the dose that can be used even For short-term Acetaminophen administration. Tolerance causesdrug doses to mainAcetaminophen (Tylenol@) is an effective analgesic tain pain conlrol and to experience withdrawal, and for mild to moderately severe pain; however, unlike causesa consequent rebound increase in pain when an NSAID, it has no clinically significant antiinflamuse of the drug is decreased or discontinued after matory activity.lsa Taken in the same dosage as long-term use. Opiates are generally used clinically to aspirin, it has analgesic and - .antipyretic effects reliene postoperative pain or pain due to malignancy' comparable to those of aspirin.l5aAcetaminophen ts Unfortunately, concerns about tolerance and side administered primarily by the oral route, although effects frequently result in the administration of administration by suppository is effective for patients insufficient doses of these medications to patients who are unable to take medications by mouth. with severe pain, resulting in unnecessarilyhigh levAcetaminophen is useful Forpatients who cannot toiThe risk of psychological addiction els of pain.157,IsB erate NSAIDs because of gastric irritation or when or habituation should not prevent the appropriate use prolonged bleeding time causedby NSAIDs would be of opiate medications, particularly in the managea disadvantage.Prolonged use or large doses of acetament of terminal illness. minophen can causeliver damage;this risk is elevated Opiates can be delivered by mouth, intravenously, an occaalso are rashes Skin alcoholic. in the chronic 6 popular or by direct intraarticular iniection.159'160 sional side effect of this medication. particuiarly and effective means of administration, for hospitalized patients, is patient-controlled anaiOpiates a pump to Opiatesarenarcoticdrugsthat containopium,deriva- gesia (PCA). With PCA, patients use ielf-administer smali, rcpeated intravenous doses' dvesof opium,or any of severalsemisyntheticor synThe amount of medication delivered is limited by thetic drugs with opium-like activiqy. Morphine, preestablished dosing intervals and maximum doses hydromorphone, fentanyl, and meperidineare exama defined period. Pain control is more effective within appiicaclinical for used pies of opiatescommoniy eFfects are less common with this adverse and slightly have drugs tions. Although these opiate than with more convenadministration oF means opito all bind they differentmechanismso[ action, opiate administration tional,physician-controlled of them of all receptors,and the-effects

qut mucosa. Thus COX2 inhibitors have more speiific antiinflammatory effects and a lower risk of gastrointestinal irritation and bleeding. NSAIDs are primarily administered orally, although one, ketorolac fforadol@), is available for administration bv iniection.15311t" mode of administration does not aiter the analgesic or adverse effects of these

ate-specific methods.'"','"" are reversed by naloxone'1ssThe opiates differ and primarily in their potency, duration of action, restrictionof useasa resultof variationsin pharmaco- Antidepressants particularlythe tricyclicssuch as Antidepressants, dynamicsandpharmacokinetics' (Elavil@), have been found to be an amitryptiline It hasbeenproposedthat opialesprovideanalgesia of chronic pain treatcomponent adjunctive effective by mimicking the effectsof endorphinsand binding effective for this being doses with smaller ment, receptorsitesin the centralnervous to opiate-specific for the treatused typically those than application systlm.ls6'1heymay also relievepain by inhibiting these drugs o[ The efficacy depression.l63'164 of ment tire release of presynaptic neurotransmittersand to be thought pain is of chronic treatment the for inhibiting the activity of interneurons early in the and function, nerve on sleep, effects their to nociceptive pathways to reduce or block C-Fiber related with chronic patients that shown have Studies mood. inputsinto the dorsalhorn.116 pain who are also depressedreport much-higher levWhen givenin sufficientdoses,opiateswill control Lls of pain and show more pain-related behaviors even the most severeacutepain with tolerableside

One o PATHOLOGY AND PATIENT PROBLEMS

-j:an those who are not depressed.1'6s'1'66 Although it -i not certain if the higher 1evel of pain in such :arients is the cause or the product oF their depres::cn, the use of antidepressants in either situation ::ray prove beneficial. Spinalanalgesia :-ain relieFmay be achieved by the administration of irugs such as opiates, local anesthelics,and corlicos:eroids into the epidural or subarachnoid spaceof the ,rinal cord.167This route of administration provides ,nalgesia to the areas innervated by the segments of ::e cord receiving the drug and is therefore most =Jective when the pain has a spinal distribution, such .s a dermatomai distribution in a single limb. The :im.ary advantages of this route oF administration =:e that the ' ^ ^ - " .drus * D " . / | bvoasses the blood-brain barrier .:rd that high concentrations reach the spinal cord at :riate receptors at sites of nociceptive transmission, --:rusincreasing the analgesic effects while reducing :dverseside effects. Opiates administered spinally exert their effects by 'rimulating opiate receptors in the dorsai horn of -:'respinal cord.168When administered spinally, fatsoluble opiates have a rapid onset and a short dura=on of action, whereas water-soluble opiates have a slow onset and a more prolonged duration of .ction.169 Local anesthetics delivered spinally have --ne unique abilir,y to completely block nociceptive =ansmissionl however, with increasing concentra:on, these drugs also block sensory and then motor =ansmission, causing numbness and weakness.17o {igh dosesof these drugs can also causehypotension. These side effects of local anestheticslimit their appli;ation to the short-term control of pain and diagnostic rurposes. Catabolic corticosteroids, such as cortisone and dexamethasone, can be administered to the epidural or subarachnoid spaceto relieve pain due to nfiammation of the spinal nerve roots or surrounding strLlctures. These drugs inhibit the inflammatory :esponse to tissue injury; however, because of the side effects of repeatedor prolonged use, including fat and muscle wasting, osteoporosis, and symptoms of Cushing's syndrome, these drugs are not suitable for iong-term application.

Localinjection Local injection of a corticosteroid,opiate,or a local anestheticcan be particularlyeffectivefor relieving pain associatedwith local inflammation.ls9Such

67

injections can be administered into joints, bursae, trigger points, or around tendons and can be used for therapeutic purposes, to relieve pain, or for diagnostic purposes in identification of the structure(s) atfauh.l7l Although this type o[ treatment can be very effective, repeated local injections of corticosteroids are not recommended because they can cause tissue breakdown and deterioration. Local injections of corticosteroids directly after acute trauma are also not recommended because these drugs reduce the inflammatory response and may thus impair healing. Local injections of aneslhetics generally provide only short-term pain relief and are therefore used primarily during painFulprocedures or J:^^-^^+:^^11,, u r d S r r u ) L r L4 r r y .

PhysicalAgents Many physical agents effectively control or relieve pain. They are thought to exert these effects by moderatingthe releaseof inflammatory mediators, modulating pain at the spinal cord level, altering nerve conduction, or increasingendorphin levels. They may also indirectly rcducepain by decreasing the sensitivityof the musclespindlesystem,thereby reducingmuscle spasms,or by modifying vascular tone and the rate of blood flow, thereby reducing 4 lnaddition, physicalagents edemaor ischemia.172-17 may reducepain by helpingto resolvethe underlying causeof the painfulsensation. Different physical agentscontrol pain in different ways. For example, cryotherapy,the applicationof cold,controlsacutepain in partby reducingthe metabolic rate and thus reducing the production and reieaseof inflammatorymediatorssuchasserotonin, histamine,bradykinin, substanceP, and prostaglanThesechemicalscausepain direcdyby stimudins.17s iating nociceptors and indirectiy by impairing the local microcirculationand, in so doing, can damage tissueandimpair tissuerepair.Reducingthe releaseoF inflammatory mediatorscanthus direcdy reiievepain causedby acute inflammation and may indirectly limit pain by controllingedemaand ischemia.These short-termbenefitscan also optimize the rate o[ tissuehealingand recovery. Cry otherapy, thermotherapy, electrical stimulation, and traction, which provide thermal, mechanical, or other nonnociceptivesensory stimuli, are thought to alleviate pain in part by inhibiting pain transmissionat the spinalcord. Physicalagentsthat

62

3 . Pain

act by this mechanismcan be usedfor the treatment 'needed,and so becomesmore independentof the of acuteand cfuonic pain becausethey do not gener- health care practitionerand pharmacologicalagents. ally produce significant adverse effects or adverse The application of such physical agents at home interactions with drugs, and they do not produce can be an effective component of the treatment physical dependencewith prolonged use. They are of both acute and chronic pain.177This type of selfalsoeffectiveand appropriatefor pain causedby contreatment can also assistin containins the costs of ditions that cannot be direcdy modified, such as medicalcare. pain causedby malignancyor a recentftacture,and Physical agents.usedeitheraloneor in conjunction for pain caused by peripheral nervous system with other interventions, such as pharmacological pathology, such as phantom limb pain and periphagents,manual therapy, or exercises,can also help eralneuropathy.lT6 remediatethe underlying causeof pain while conElectrical stimulation is also thought to control trolling *re pain itself. For example, cryotherapy pain in part by stimulatingthe releaseof opiopeptins applied to an acute iniury controls pain; however, at the spinalcord and at higherlevels.l2BStudieshave this treatment also controls inflammation, limiting shown that pain relief by certain types of electrical further tissue damage and pain. In this case, the stimulationis reversedby naloxone.128 use of NSAIDs, rest, elevation, and compression, Physicalagentshave many advantagesover other in conjunction with cryotherapy,could also prove pain-modifying interventions. They are associated beneficial, although it may make assessmentof with fewe5 andgenerallylesssevere,sideeffectsthan the benefits of any one of these rnterventlonsmore pharmacologicalagents. The adverse effects from difficult. The selectionof physical agentsand their using physical agentsto control pain are generally specificmechanismsof action and modesof applicalocalized to the area of application and are easily tion for controlling pain are discussedin detail in avoidedwith care in applying the treatrnent.When Section2 of this book regardingthe differenttypes of usedappropriately,attendingto all contraindications . h - . ; " , 1 " " " . r . and doserecommendations,the risk of further injury ftom the useof physicalagentsis minimal. For examMultidisciplinary PainTreatment Programs ple, an excessivelywarm hot pack may causea burn in the areaof application,but this risk can be miniOver the past 2 to 3 decades,multidisciplinary prorntzedby carefully monitoring the hot pack's tempergramshave beendevelopedspecificallyfor the treatature, using adequate insulation between the hot ment of chronic pain.a,178 Theseprogramsare based pack and the patient, not applyinghot packsto indion a biopsychosocialmodel of pain and attempt to vidualswith impaired sensationor an impaired abiladdressthe multiple facets of chronic pain with a ity to report pain, and by checkingwith the patient multidisciplinary coordinated program of care.4'179 for any sensationof excessiveheat. Patientsalso do These programs attempt to addressnot only the not developdependenceon physicalagents,although physical and physiological aspectsof the patients' they may wish to continue to use them even after pain but also the behavioral,cognitive-affective,and they are no longer effective because they enjoy environmental factors contributing to their sympthe sensation or attention associatedwith their toms by the useof medical,psychological,and physiapplication.Ior example,patientsmay wish to concal interventions.lBo,lBl tinue to be treatedwith ultrasoundeventhough they Psychologicalintervention is focusedon improvhave reacheda stageof recoverywhere they would ing the coping skills of patients and modi$ring benefit more from active exercise.Physicalagents their behavior,whereasphysicalactivitiesarefocused also do not generallycausea degreeof sedationthat on reversing the adverse effects of the sedentary would impair an individual'sabiliry to work or drive lifesryle adopted by most patients with chronic sarery. pain. Coping skills can be improved with relaxation Many physical agents have the additional training, activity pacing,distractiontechniques,cogadvantageof being readily used independendyby nitive restructuring, and problem solving.1B2,1B3 patientsto treat themselves.Ior example,a patient Behaviormodificationusingthe principlesof operant can be educatedto apply a pain-controllingagent, conditioning can also alter the patient's perception such as heat, cold, or electricalstimulation, when of and responseto pain.184Graded activation and

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One . PATHOLOGY AND PATIENT PROBLEMS

::.:3rciseprograms,in which the patient iearns the ---:erenceberweenhurt and harm, can help patients .,.-:ih chronic pain retum to a more functional, ,:ive lifestyle.l8s The patients' family members ::: generally involved in these programs by -::rning appropriatecopingskillsfor *remselvesand -:e patient. Such involvement can assistthe family :embers to help individuals with chronic pain :-.cre effectively rather than reinforce pain-related ::haviors. In contrastwith traditional treatment approaches :--,acutepain,in which the goal of careis to eliminate =e sensation of pain, the goals of care in most =ultidisciplinarypain treaffnentprogramsalsoinclude ::rning to cope and function with pain that may r rt resolve,although frequently patientsalso report

63

a reduction in pain after completing these proGoals of treatment also generally grams.186'187 include decreasingdependenceon health care per sonnel and pain relieving medications,particularly h a b i t - f o r m r nogp i a r e so r o t h e rn a r c o L i cisn:c r e a s i n g physical activities; and retuming patients to their usual social roles. If necessarynarcoticmedications are replacedwith non-habit-forming drugs or with nonchemicalmodes of pain relief such as exercise or physical agents.aMany studies have shown that multidisciplinary pain treatment programs do result in increasedfunctional activity levels while reducing pain behaviors and the use of medical i n c e r v e n t i o ni ns p a r i e n t sw i t h c h r o n i cp a i n . 8 8l q l These programs have also been shown to be cost elfe ctrve.rBI,I 92194

) Clinical CaseStudies a The following casestudiessummadzethe conceptsof pain discussedin this chapterBasedon the scenariopresented,an evaluationofthe clinicalfindingsandgoalsof ft€atmentareproposed.This is followed by a discussion ofthe factorsto be consideredin treatmentselection.

Case'l M? is a 45-year-oldfemale who has been referredto physicaltherapywirh a diagnosisoflow backpain and a physician'sorderto evaluateand fteat.MP complainsof severecentral low back pain that is aggravatedby any movement, particularly forward bending. Shereports no radiation of pain or other symptoms into her extremities.Paindisturbsh€r sleep,and sheis unableto work at her usualsecretarialjob or perform her usualhousehold taskssuchasgroceryshoppingand cleaning.Shereports that the pain startedabout4 daysago,whenshe reached to pick up a suitcase,and hasgraduallydecreasedsince its initial onset ftom a severity of 8, on a scaleof 1 to 10,to a severity of 5 or 6. Her only curent treatment is 600 mg ibuprofe4 which she is taking 3 times a day. The obiective exam is significant for resuicted iumbar range of motion in all planes. Forward bending is restricted to approximately 207o of norma| backward bending is resfticted to approximately 50% of normal, and side bendingis resriccedro approximately30qoof nonnal in both directions. Palpablemuscleguardingand tendemess in the lower lumbar areaoccur when the patient is standing o! prone. All neurological testing, including straight

leg raise and lower exftemity sensation, strength, aad reflexesarewithin normalLirnics. OF CLINICALFINDINGS EVALUATION This patient seeksmedical treatment for the impainrlents o[ low back pain and restricted lurnbar range of motion. These impairments have resulted in difficulties with her nomal functionalactivitiesof sleeping,working, shopping, and cleaning. A.lthough further analysis may help identify the speciticsffucturescausingthis patient'spain, its rccentonsetrelatedto a specificevent usingthe painful areaand its gradualresoludonover tl.re last few days indicatethat her pain is acute and is the result of local musculoskeletalinjury and probable inFlammadon. PREFERREDPRACTICEPATTERN Impaired Joint Mobility, Motor lunction, Muscle ?erformance, Range of Motion, arrd Reflex Integrity AssociatedWith SpinalDisorders,(4I). PLANOF CARE The goalsof treatmentat this time includecontrolling pain to allow MP to sleep and return to other functional activities as soon as it is safe for her to do so. The anticipated goals of treatment would also include regaining normai lumbar rante of motion and, ideally, preventing a recurtence of the present svmDtoms, Continued

64

3. Pniu

) Clinical Case Stttdies-cottt'd ASSESSMENTREGARDINGSELECTIONOF THE OPTIMAL TREATMENT The optimal intervention would ideally address the acute s1'rnptomof pain and the underlying inflammation and, if possible,would help to resolveany underlying structural tissue damage or changes.Although a single ffeatxoentmay not be abie to addressall of theseissues, treafinentsthat addressasmany of theseissuesaspossib1eand that do not adverselyaffectthe patient'sprogress arerecommended. As is explainedingreaterdetailin Part 2 of this book, a number of physical agents, induding cryotherapyand electricalstimulation,may be used to control this patient's pain and reducethe probable acute inflammationof the lumbar structures,and lumbar traction may also help to relieve her pain while modifying the underlying spinal dysfuncrion.

Case 2 tj is a 45-year-oldfemalewho hasbeen referredfor therapy with a diagnosisof low back pain and an order to evaluate and treat, with a focus on developing a home program. TJ complains of stiffaess and generalaching of her lower backthat is aggravated by sittingformore than 30 minutes.she reportsoccasiorulradiationof pain into her left lateral leg but no other s;.rnptoms in her extremities. She states*rat the pain occasionallydisturbsher sleep,and she is unableto work at her usualsecretarial job becauseof her limited sitting tolerance.Shecanperform most ofher usualhouseholdtasks,suchasgrocery shopping and cleaning, although she ftequently receives help from her family. She reports that the pain started about 4 years ago,when she reachedto pick up a suitcase,and althoughit was initially severe,at a levelof 10 on a scaleof 1 to 10, and subsidedto somedegreeovel the first few weeks, it hasnot changedsignificandy in the past 2 to 3 years and is now usually at a level of 9 or greater Shehashad multiple diagnosticteststhat have not revealedany significaotanatomicalpathology,and she has received multipie treatments, including narcotic analgesicsand physicaltherapy consistingprimarily of hot packs,ultrasonography, andmassage, without significant benefit. Her only current treaftnent is 600 mg of ibuprofeq which sheis taking 3 times a day.The objective exam is significant for restricted lumbar range of motion in all planes.Forward bending is restrictedto approximately40% of normal, backward bending is restrictedto approximately50% of normal, and side bendingis resffictedto approximately507oof normalin both directions.?alpationrevealsstiffnessof the lumbar facetjoints at L3 throughL5 and tendemessin the lower lumbar area. All neurologicaltesting, including lower extremity sensation, strength, and reflexes are within

a

normal limits, although srraightleg raisingis limited to 40 degreesbilaterally by hamstring tightness and prone knee bending is limited to 100 degreesbilaterally by quadricepstighmess.T| is 5 leet 3 inchestall and reports her weight to be 180 pounds.She reportsthat she has gained 50 pounds sinceher initial back injury 4 years ago. EVALUATIONOF CLINICAL FINDINGS This patient seeksmedical ueatrnent for the impairments of low back pain and restricted lumbar range of motion. These impairments have resulted in difficulties widr her normal functional activities of sleeping, working, shopping, and cleaning. Although funher analysis may help identify the specificstructurescausingtJrispatient's pain, the long duration of the pain is well beyond t}re normal time neededfor a minor backinjury to resolve.The lack of changein her pain over the previous years and its lack of responseto multiple treatmentsindicatethat her pain may have a variety of contributory factors beyond local tissue damage, including deconditioning, psychological dysfunction,or socialproblems. PREFERREDPRACTICEPATTEFN Tmn:irarl

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Glenohumeralpassiveinferior and posterior gLideare both restrictedon the left. MP has had no prior tr€atment for tlis prcblem. EVALUATION OF THE CLINICALFINDINGS This patient presentswith impairments of restrictedactive and passive motion of her left shoulder. These have resulted in a reduced abiliry to perform activities of daily Iiving, induding grooming and dressing. This patient's signs and syrnptoms, and the duration of her problem, indicate that the condition has probably proglessedto t}rercmodelingstageoI healing,with somepossibllity of chronic inflammation. She does not repoft significant pain at *ris time, and it appean that her left shouldermotion is restrictedby shorteningof the antedor inferior glenohumeraljoint capsule.No tone abnormaliuesarenoteo. PREFERREDPRACTICEPATTERN Impaired Joint Mobiliry, Motor lunctioq Muscle Performance, and Range of Motion Associated Witlr ConnectiveTissueDysfunctioq (4D)

436

13 . Ihtegdting

Physical Agents irtto Patiett Care

) Clinical Case Studies-cont'd PLAN OF CARE The goals of treatment at this time arc to restore normal active and passivemotion of the left shoulder and to allow MP to perform all activities of daily living in her prior mannerusingboth upper extremities.Becauseher shoulder ROM is probably restricted by soft tissue shonening,trhetreatmentshould be directedat increasing the extensibility and length of the shortened tissue, the anterior inferior capsuleof the glenohumeraljoint. Appropriate goals for this late stageof healing would alsobe to control scartissueformation and ensureadequate circulation. Although no strength abnormalities were noted on *ris initial evaluation, the patient's strength should be reevaluatedas she regains ROM since she may have strength deficits at tJ-teend ranges dueto disuse.Shouldstrengthdeficitsbecomeapparcnt, an additionalgoalof treatrnentwould be to restorenormal strengthto the left shouldermuscles. ASSESSMENTREGARDINGTHE OPTIMAL PHYSICALAGENT INTERVENTION(S) Thermotierapy wordd be the most appropriatephysical agent to use to increasesoft tissue extensibility and promote circulation.Becausettre tissuerestrictinethe ROM is which is deep,a deepheatingagentsucb the joint capsule, as ultrasoundor diathermy, rather than a superficialheating agentsuchasa hot pack, should be used.A deepheating agent applied to the anterior inferior aspect of the shoulder will increasecapsularextensibfity by elevating tie tissuetemperatureand,sincetissueextensibility will be increasedonly while the tissueis warm, the capsuleshould be stretchedduring or immediately after the applicationof this agent. Motorlevel electrical stimulation and wate!basedexercisemay also be used as componentsof an actives&etchingor stlengtheningprogram for this patient. PROPOSEDTREATMENTPLAN AND RATIONALE The most appropriatephysical agent for heating the anterior inferior capsule is thermal-level ultrasound. A.lthoughdiathermy could be usedfor this application, it would be less appropriatebecausemost lorms of diathermy carfrot be direct€dto such a small areaand becausediathermy devicesare not readily availablein most clinicsat this time. Ultrasoundshouldbe applied to the anteriorinferior aspectofthe glenohumeraljoint, with the shoulderina positionthat placestensionontie anterior inf€dor joint capsule,which would be at the limit of range for combined flexion, abductioq and extemalrotation.Manual joint mobilization and active and passivestretching should be applied during and immediatelyafter the applicationofultrasoundin order

I

to optimize gains in ROM, and the patient should be instructedin a home programof sffetching€xercisesin order to maintain and progressin gaining ROM. This programof deepheat and stretchingtechniquesshould be continued until the patient regains her full range of active, passive,and accessorymotions. Strengthening exercisesshould be addedif weaknessis noted at the end ofthe rangeasROM is regained.

Case 6 LM is an B4-year-oldmale with a stageIV ptessureulcer over his right greater trochanter LM has suffered 3 strokesover the last 10 years.At this time he is bedbound,hasflexionconuacturesof both upperandlower extremities,is cachecticand is beingfed via a nasogastric tube. The pressureulcer was first noticed 2 weeks ago, when itwas a stageII, and its areawas 4 cm by 3 cm. At this time LM's tuming schedulewas increasedfrom every4 hoursto every2 hours,and his bedwas changed from a regularmattressto an air mattress.however,in the last 2 weeks tl-rewound has worsened.It is now a stageIV, and its area has increasedto 6 cm by 5 cm. Approximately50% of the wound bedis blackand50% is yellow. Thereis no underminingpresent. EVALUATIONOF THE CLINICAL FINDINGS This patient presentswith impaiments of lossof tissue integrity,decreased activeand passiverangeof motion, and decreased strength.The tissueis not demonstrating healingat this time. Tissuehealingmust be initiated at the inflammatory stage. PREFEHREDPRACTICEPATTERN Impaired Integumentary Integrity Associatedwith Skin InvolvementExtendinginto lascia,Muscle,orBone and ScarFormation,(ZE) PLAN OF CARE The proposed goals of treatment at this time are to remove necrotic tissueand optimize the environment for tissuehealing.It is also hoped that wound closure canbe achieved;howeve! with *ris patient'spoor generalstateof healt!, wound closuremay not be possible. If it is not possible,the goalsof treatmentwould be to minimize wound progressionand reduce the risk of wound and systemicinfection. ASSESSMENTREGARDINGTHE OPTIMAL PHYSICALAGENT INTERVENTION(S} Hydrotherapy or sharp tools can be used to debride necrotictissueftom the wound. Debddementwill €nhance

ThTee . INTEGRATING PIIYSICAL AGENTS INTO PR-ESENT AND FUTURE PK4CTICE

wound healing and reducethe risk of infection. Dead tissuecannothealand canact asa mechanicalbarrierto tissue growth and as a nidus for infection. Electrical stimulationor ulftasoundmay also be usedto facilitate healing. PROPOSEDTREATMENTPLAN AND RATIONALE The physical agents that could promote progression toward the goalsof treaffnent at this dme, and tllat are not contraindicated,indude hydrotherapy, electricalstimulation, and ultrasound.Nonimmersion hydrotherapy, such as pulsed lavage, is safest and most effective to use for wound debridement becausethis allows control of the water pressureand avoidssoakingthe wound in contaminated water. Although both electrical stimulation arld ultrasound have both been shown to enhancepressure ulcer healing, since the evidencefor the effectivenessof electricalstimulation for tlis application is stronger,electrical stimulation is recommendedfor treatrnent of this patient. It is recommended that sensory-levelhigh-volt pulsed current electrical stimulation be used since most studies have shown t}lis to promote wound healing. In addition to interventions usingphysicalagents,a ftequent tuming schedule avoiding the right side, posirioning to minimize pressureon the dght lateral hip, and transfer tecfuriquesthat minimize shear and ftiction are recommended, A wound dressingthat keeps the wound bed moist, keeps the sunounding skin dry, and does not reguireft€quentchangesshouldbe used.A supportsurface that optirnizespressuredistribution and moisture controlshouldalsobe used. FOLLOW-UP Two months later the wound on LM's right lateral hip, in the areaof the greaterftochanter,is stil1open.However,

437

there is no longer any necrotic tissue present, and the wound base is now red. The area of the wound has also decreasedftom 7 cm by 5 cm to 3 cm by z cm. EVALUATION OF THE CLINICALFINDINGS The absenceof necrotic tissue and the red wound base,which is most likely granulationtissue,indicates that this wound has progressedfrom the inflammatory stage of healing to the proliferative stage of heaLing. PLAN OF CARE The primary goals of treatment at this time ale to continue to optimize the environment for wound healing and to protectthe wound. Removalof necrotictissueis notneededsincenon€is present. ASSESSMENTREGARDINGTHE OPTIMAL PHYSICALAGENT INTERVENTION(S} Debridement with hydrotherapy should be discontinued at this time as there is no longet necrotictissue in the wound and the granulation tissue tlat is present may easily be damaged by the hydrotherapy. Elecuical stimulation may be continued to enhance tissuehealing. PFOPOSEDTREATMENTPLAN AND RATIONALE It is proposed that hydrotlerapy be discontinued. Although electricalstimulation may be continued to promotetissuehealing,a trial without this intervention is recommendedso that disturbanceof the lragilegranulation tissue is minimized. Tissue healine should be carefullyrnonitoredand electricalstimulati,cnresumed ifhealing plateausor regresses.

PrefenedPhysicaiTherapistPracticePattemssMl4D,4l,5D,7Dand 7El are copyright 2002American PhysicalTherapy Associarion.All

Chapter Review It is recommended thatphysicalagentsbeselected for patienttreatmentwhen they canbe expectedto promote progressiontoward the goalsof treatment,can be appliedsafely,and when the support for their use hashigh scientificmedt. \ 41enappropriatelyselected andapplied,physicalagentscanaccelerate tissuehealing, control pain, reduce motion restrictions,and modify muscletone.However,for their applicationto be safe,physical agentsmust not be applied when contraindicated,and al1 recommendedprecautions must be adheredto. A.lthoughthere are specificcontraindicationsand precautionsto the applicationof

different physicalagents,pregnancy,malignancy,the presenceof a pacemaker,impaired sensation,and impaired mentation generallyindicate the need for caution when consideringthe use of any physical agent.A ffeatmentcanbe consideredto havehigh scientific merit if its useis supportedby valid theories,if it is designedfor specifictypesotpatients,if its potentially adverseeffectsarepresented,andifits efficacyis supportedbyweil-designedstudiespublishedin peerreviewed joumals. If the application of a physical agentis expectedto promoteachievementof the goals of treatment,to be safe,and to have high scientific merit, the cost, convenience,and availability of that

434

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Physicdl Agents into Patient Cfure

9. Wilson DH: Treatmentof soft tissueinluriesby pulsed electricalenergy,Br MedJ 2:269-270, 1972. 10. PenningtonGM, Danley DL, SumkoMH: Pulsed,nonthermal, high frequency elecromagnetic field (Diapulse) in the treatmentof GradeI and CradeII anlle sprains, Milit Med 153:10I-104,1993. 11. Kaplan EG, Weinstock RE: Clinical evaluation of Diapulseasadjunctivetherapyfollowing foot surgery/ An PodiattAssoc58(5):218-221 , 1968. 12. Cote DJ,PrenticeWE, Hooker DN et al: Comparisonof threetreatmentproceduresfor minimizing anklesprain 6' 1988. swelLng,PhysTher68(7)11072-107 13. Wilkerson GB: Treatment of inversion ankle sprain through synchronousapplicationof focal compression and cold,AthleticTraixing26:220-225 , 1991'. 14. Quillen WS, Roullier LH: Initial managementof acute compression anldesprainswith rapidpulsedpneumatic and cold,J OnhovSvortsPhysTher4:39-43, 1982. 15. Pilla AA, Martin DE, SchuettAM et al: Effect of PRI therapy on edemafrom gradesI and II ankle sprains:a placebo controlled randomized, multi-site, doubleblind clinicalstudy,/ AthleticTratuing3I:g'3,1996. 16. LehmannJ, MasockA, Warren C et al: Effect of therapeutic temperatureson t€ndon extensibilitT,ArchPhys Med Rehabil5I:481-487, l'970. 17. LehmannJF,Delateur BJrApplicationo[Heat and Cold in the Clinical Setting.In LehmannJl @d):Thetapeutic Heat aud Cold, ed 4, Baltimore, 1990, Williams & Wilkins. 18. Lehmann J! DeL atevr BJ Therlleutic Heat and Cold,ed 4, Baltimore,1990,Williams & Wilkins. 19. Lehmarur JF, Delateur BJ, Stonebridge JB et al: References in local L et al:Changes Therapeutic temperature distribution produced by 1. WestonM, TaberC, Casgranda to trauultrasoundasmodified by dosageand volume of tissue bloodvolumeduringcoldgel packapplication . 19(4):197'199, ArchPhysMed Rehabil48:662-666,1967 nhoV Phys Ther exposed, Spon matizedankles,/O 20. LehmannJF,Delateur BJ,Waren G et al: Boneand soft 1994. tissueheating producedby ultrasound,ArchPhysMed upperextremitycoolingfrom a 2. Wolf SL:Contralateral 1971. Rehabil48:397-401,1'967. PhysTher51:758'165, specificcoldstimulus, iradiation 21. Kamm RD: Bioengineeringstudiesof periodic external of ultrasonic 3. BickfordRlI, Duff RS:Influence compression as prophylaxis against deep venous andbloodflow in humanskeletalmuson temperature 1953. thrombosis: Part I: Numerical studres,J BionechEng cle,CircRes7:534-538, L04:87-95, 1982. 4. Iox HH, Hilton SM: Bradykininformationin human skinasa factorin heatvasodilation, J Physiol142:219' 22. Olson DA, I(amm RD, Shapiro AH: Bioengineering studiesofperiodic extemalcompressionasprophylaxis 1958. Rheumatology againstdeep venous thrombosis:PartII: Experimental 5. SchmidtKl: Heat,coldandinflammation, studies on a simulated\eg,J BionechEng 104:96-104, 38:39L-404,1979. 1,982. 6. McCullochJ: Physicalmodalitiesin wound managevasopneumatic devicesand hydro- 23. RischWD, KoubenecHJ,BeckmannU et a1:The effect ment: ultrasound, 35-37, 1995. of gradedimmersionon heartvolume,centralvenous therapy,Ostomy VoundMaxage41(5):30-32, pain?A reviewof dreclinical preisure,pulmonary blood distribution and heart rate 7. ErnstE.IialkaV lcefteezes Arch374:117,197B. ln man,Pfluegers of analgesiccoLdtherapy,J PainSynyton effectiveness 1994. 24. Haffor AA, Mohler JG,HarrisonAAC: Effectsof water 9(1):56-59, Manage formsof immersionon cardiacoutput of lean and fat male sub. TB,CoppEP:Theeffectsof therapeutic 8. Benson Ariat SyaceErviox Med heatandiceon the painthresholdof the normalshouliectsat restand du ng exercise, 7974. 62:125, 1991. Rehabil 13101-104, der.Rheuuanl

asentshouldalsobe consideredin treatmentselection. Although the applicationof a physicalagentmay be the only intervention used with a patient, generally physical agentsare used in conlunction with each other or in conjuncdonwith other intewentions,such as activeexercise,passivemobilization,or functional activities,in orderto optimize patientoutcome. The selectionand application of physical agents may vary under differenthealthcaredeliverysystems due to differencesin practical and financial constraints. Although under all systems the clinician should seek to provide the best possible care for patients, cuffent health care delivery systems frequendy requirethat suchcarealsobe providedin the most cost-effectivemarner. Costsmay be controlled by havingpatientsorpractitionerswith lowerskill levelsapply Eeatmentsunderthe directionof a therapist, when this can be done correcdyand safelyand when effectivenesscan be maximized by evaluating the effectsof specificinterventionson Patientfunctional outcome and selectingthose that are shown to produce the greatestbenefiq however, the potential for conflict beween minimizing cost and maximizing benefit can make ffeatment seiectiona complexand difficult process.The readeris referredto the Evolve for website at http://evolve.elsevier.com/Cameron study questiors pertinent to this chaptet

Three t INTEGRATING PIIYSICAL AGTATS I tfo pRE SENT AND FUTIIRE 9RAC.1ICE

25. Balldin UI, Lundgren CEG, Lundvali J et al: Chaneesin the elimination oF 133 Xenon from rhe anterior-ribial mu-sclein man induced by immersion in water and by shifts in body position, Aerospace Med 42(5):499 , 1971. 26. Ward RS: Pressuretherapy for tl:e control of hypertrophic scar formation after burn injury: a hisrory and review,J BurnCateRehabil12:257-262,j.991. 27. LarsonDL, Abston S, EvansEB et al: Techniquesfor decreasingscar formation and contracturesin the bumed parient,J Trauna 11:807-823, 1971. 28. Kircher CW, Shedar M\ Shetlar CL: Alteration of hypertophic scarsinduced by mechanicalpressure, Arrh DernatoI 1| | :60-64,1975. 29, WadeJ:Sportssplash,Rehabil Matage 10(4)164-70,1997 . 30. WarrenC, LehmannJ,KoblanskiJ:Elongationof rat tail cendon:effect of load and temperarure,Archphys Med Rehabll52:465,47 4. 484.I97 1. 31. Warren C, Lehmann j, KoblanskiJ: Heat and stretch procedures: an evaluationusingrat uil tendon,4r./r Phy:M edRehabil 57:122-| 26.1976. 32. GerstenIW: Effect of ulftasoundon tendon extensibiliry,An J PhysMed 34:362-369 , ISES. 33. Lehmann J! Brunner GD, Stow RW pain threshold measurementsafter therapeuticapplication of ultrasound, microwaves and,inftared, ArchphysMed Rehabil 39560-565,1958. 34. JudovichB:Lumbar tractionrherapy,JAA4A159:849,1955. 35. CheadeMD, EsterhaiJL:Pelvictractionastrearmentfor acutebackpaln, SVixe 16:1379 -1381,,1991,. 36. BonicaJJ:TheMaxagemettof Pain, ed 2, philadelphia, i990.Lea& Iebiger. 37. Hood LB, Chrisman D: Intemittent pelvic traction in the ueatment of the ruptured ilterverteb nl disc,phvs Thet48:21-30,1968. 38. Mathews JA, Mills SB,JenkinsVM et al: Backpain and sciatica:conftolledtrialsof manipulation,tractioq sclerosant, and epidural injections, Br J Rheunatol26: 416-423,1987 . 39. Lidstrom A, ZachrissonM: Physicaltherapy on low backpain and sciatica:an att€mptar evaluation,ScandJ RehabilMed 2 :37-42. 1970. 40. Sicard-Rosenbaum i, Lord D, Danoff JV et al: Effectsof continuous tlerapeutic ultrasound on growttr and metastasisof subcutaneousr,]r]uineturIlors,phvs Thet 75(l):3-ll, 1995. 41. Burr B: Heatasa theu?euticmodalityagaixstcancet\epott 16.Bethesda,MD, 1974,U.S.NationalCancerInstiiute. 42. BakerLL, McNeal D\ Benton LA et al: Neuromuscular Electical Stfutulation:A PracticalGuide, ed.B, Downey, CA. 1993.RanchoLosAmigosMedicalCenrer.

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43. Carmick Jr Clinical use of neuromuscularelectrical stimulation for children wirh cerebral palsy, phys Ther 73t505-513 , 1993. 44. CarmickJ: Use of neuromuscularelectricalstimulation and a dorsalwrist splint to improve hand function of a child with spastichemiparesrs, PhysThet77(e:66I-671, 1997. 45. Cyriax J: Textbooleof Orrhoyedk Medicfue, Volume I: Diagxoskof Sof TissueLesions, London, 1982,Bailliere Tindall. 46. LentellG, HetheringtonT, EaganJ etal: The useof thermal agentsto influence the effectivenessof low load prolonged stretch, J Ofthop Spon Phys Ther !6(3): 200-207,1992. 47. TravellJC, Simor,sDG:MyafascialPaix andDysfuxctioa: The Triger PointMaxual, Bahtrnore, 1983, Williams & Wilkins. 48. SimonsDG, TravellJG:Myofascialoriginsof low back pain. 1: Principles of diagnosis and treatment, postgtad Med 73(2):70-77 , 1983. 49. Harns SR:How should treatmentsbe critiquedfor scientlt\cmeit? PhysTher76(2):175-I8!, !996. 50. VerrierM, FalconerK,Crawford SJ:Acomparisonof tissue temperaturc following two shoftwave diatherrny tecb,tiques, Physiother Caxada29(7):21-28 , 1977. 51. Hand fW: Biophysicsand technology of electromagnetic hyperthemia. lq Guthrie M, ed: Method.sof ExterxalHyVethermicHeattu& Berlin, 1990, SpringerVerlag. 52. Comadi E, PagesIH: Effectsof continuousand pulsed microwave irradiation on distribution of heat in the glutealregionof minipigs,ScaxdJ RehabllMed2I:59-62, 1989. 53. Golden GS: Nonstandardtherapiesin developmental disabiliti.es,An J Dis Child 134:487-491, fgg} . 54. WeinbergerA, NyaskaA, Giler S:Treatmentof eryerimental inflammatory slmovitis with continuousmag-1201, 1996. netic fieId, IsrJ Med Sci32(1,2):7197 55. AbramsonDl: Physiologicalbasisfor the useofphysical agentsin p€dpheralvasculardisorders,ArchPhysMed Rehabil46:216-244 , 1965. 56. Stillwell GK: Physiatricmanagementof postmastectomy lymphedema, Med Clin Nonh An 46105I-1068, 1962. 57. Rucinski TJ, Hooker D, PrenticeW: The effects of intermittent compressionon edema in post acute ankle spralrc,JOSPTL4Q):65-69,\991. 58. SimsD: Effectsof posirioningon anlle edema,/OSpT 8:30-35, 1986. 59. PT Bdletin, 12/20/1997, p 11.

Directionsfor Futur esearch and AVVlication SUMMARY

OF 1I/F ORMATION

Why Further Research on the Use of Physical Agents in Rehabilitation Is Needed Areasfor FutureResearchon PhysicalAgents

COVERED

Methodological Characteristicsof FutureResearch on PhysicalAgents Chapter Review

oBlECrrvES Uponcomyletionofthis chaVter,thereaderwill beable to: l . Explain why there is a need for furtller research on the^useof physicalagentsin rehabilitation. Identi$r the areasin which further researchon the effectsof physicalagentsis needed.

3. Summarizethe methodolosical characteristics requaed for researchon phjzsicalagentsto guide progressin clinical practiie.

441

442

44 . Dilectiofls for Future Researchatd Apylication

RESEARCH WHYFURIHER ONTHEUSEOFPHYSICALAGENTS INREHABILITATION ISNEEDED Although, as demonstratedthroughout this book, thereis research to supporttheuseofphysicalagentsin rehabilitatioryfurther researchis neededin most areas because,as with most medicaltreatments,the available scientific evidence is genenlly insufficient to proveconclusivelythat cunentclinicalpracticeis effective or thatitis deliveredin the optimalmanfier Due to theselimitations,the currentpracticeof appiyingphysicalagentsis basedon the availableresearchfindingsin conjunctionwith prior practicepatternsand the personalexperienceof the provider.This has resultedin variability in practice among practitioners with different trainingandpersonalexperienceandftom different locations,andhasprobablyalsoresultedinlack ofoptimalcareandsuboptimaloutcomesfor somepatients. For example, al*rough shortwave diathermy is commonly used in Europe, with reportedly good results,it is rarely usedin the United States.Because this physical agent is unlikely to produce different effectsin these different regions,it is probable that either some patientsin Europeare receivingtrearments that are not effectiveor that some patientsin the United Statesare not receivins treatrnentsthat could benefit chem.Iurther reseirch will help Lo ascertainwhich interventionsare effectiveandwhich are not, which methodsand treatmentparametersto use for optimal results, the benefits that can be expected from these interventions, and who will receive the greatest benefit from them. This will enhanceclinical practiceby improving patient outcomes,increasingthe consistencyand efficienry of care, and supporting reimbursementfor treatments usingphysicalagents. It is recommendedthat future researchon ohvsical agentsfocuson applications where empiricaiclinical evidence,pdor studies,andanecdotalreportssuggest, but do not definitively prove, that certain interventions are effective.Iuture researchshould attempt to determine if current practiceis effective,and if so, how it canbe optimized,and ifnot, which alternative interventionswould be effective.As further research is performed,it is expectedthat the findingswill support many cuffent applicationsof physical agents; however, it is also likely that future researchwill directmodificationsin the applicationof somephysicalagentsandfail to supportthe continueduseof oth-

ers.Studiesmay fail to support presentpracticeif an intervention is found to be ineffective or to be less effectivethan other availabletreatmentoptions.It is also expectedthat future researchwill promote the developmentof new applicationsof physicalagents. Onceappropriateareasfor researchare selected,it is alsoessentialthat future studiesbe designedto permit readyinterpretationand applicationof their findings.In many areas,moreresearch is neededbecause flaws in the availablestudies,such as inappropriate design,the use of inappropriatetypes or numbersof subjects,lack of or poor controls,the useof measures that havenot beenshown to be valid or reliable,limited assessment of outcome,or poor reportingof the preciseintervention used, restrict the applicationof their findings.Ior example,if the effectsof an intervention have been monitored without comparison with a control group who did not receivethat interventiory it cannot be determined whether the observedeffects were causedby the interventiontherebysupportingits use,or whetler they were due to chanceor normal progressionof the problembeing treated, thus not supporting its use. Appropdately designedstudieson the useof physicalagentsin rehabilitation will demonstratewhether or not specific interventionswith physicalagentscan promote progressiontoward the goals of treatment for specific problemsand how suchbenefitscanbe optimized. High-qualityresearchin the appropriateareaswill improvethe qualityofpatientcareandprovidesupport for reimbursement for treatments using physicai agentsbasedon provenpositivefunctionaloutcomesIn the absence ofsuch studiesitis possiblethat patiens will not receiveoptimal care,and it is likely that, over time, payeff will not continueto reimbursefor irrterventionsthat havenot beenprovento be effective.

AREAS FORFUTURE RESEARCH ONPHYSICAL AGENTS Physical properties and effects ofphysical agents Physiological effects of physical agents Clinical applications of physical agents Contraiodications, precautions, and adverse effects of physical agents

ThTee C INTEGRAIING PIIYSICAL AGENTS INTO PRESENT AND FUTURE PRACTICE

There are many areas where further researchon physical agents could promote improvements in patient care. These include the physical properties and effects of physical agents, *reir physiological effects,their clinical applications,the contraindications and precautionsto tleir use,and their potential adverseeffects. Although for most physical agents there is some researchin all of these ateas,more researchis neededin order to optimize clinicalapplicationsin rehabilitation. In general, the physical properties and effects of physical agents are well understood, but their interactionswith, and their effectson, physiological processesare less clear.In most areas,even less is known aboutthe specificeffectsof physicalagentson patient function. While further understandingof the physicalpropertiesand effectsofphysical agentsmay provevaluablein the developmentof treatmentapplications,studies regardingthe changesproduced in physiologicalprocessesand the resultantclinicaloutcomes are likely to provide the most guidancefor advancing andimprovingclinicalpractice.

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factors impacting the distribution of the heat producedby thesedifferentforms of diathermyand thus increasethe safety and effectivenessof their clinical application. Another areawhere researchon the physicalpropertiesand effectsof physicalagentshasbeenvaluable is in the developmentof new physicalagents.Most devicesdevelopedin recentyearsdeliverthe sameor similartypesof energyasthat deliveredbypreviously available physical agents. However, these newer devicestake advantageof technologicaland theoretical advancesto provide greaterrangesand control of the energyintensify or frequencyaswell asimproved safety and convenience.Researchusing thesenewer devicesis neededto gain a better understandingof their physical properties, potential applications in rehabilitation, and possible advantagesover older devices.In addition, further basic scienceand engineedng studiesmay yield other physicalagentsand further deviceimprovements. The low-energycold laseris an exampleof a physical agentthat was developedin recentyearsand that is now being applied clinically in rehabilitation in somesettings.Alaserproducesa beamof electromagPhysical Properties andEffects of Physical netic energythat has the unique physicalproperties Agents of being monochromatic,coherent,and directional. Although the physical properties of most physical At this time, low-energy laserdevicesproduceelecagentsare generallywell understoodand have been tromagnetic radiation with frequenciesand waveclearlydescribed,further researchis neededto clarify lengthsthat penetratethrough only a few millimeters the nature and magnitudeof their physicaleffectson of human tissue.4,5 Further researchon the ohvsical the body.Forexample,althoughit is known that therpropertieso[ low-energylasersmay promo; the mal energyis producedby friction betweenparticles, development of devices that can penetrate more qeepry. that *re amountof thermalenergyincreases in proportion to the relative rate of motion of these partiLongwave ultrasound is anotier physical agent cles,and that the amount of thermal energyrequired thatwas recentlydevelopedforapplicationin rehabilto producea given changein temperaturein a mateitation. This type of ultrasoundhasa much lower frerial varies with the specific heat of that material, quency and a longer wavelength than traditionally without further researchthe temperature increase usedultrasound,resultingin deeperpenetration.This and the distribution of heat in a patient'sbody when type of ultrasoundwas designedto be usedfor treatdifferenttherrnalagentsare appliedcannotbe readily ment of deep tissues;however, at this time, there is or accuratelypredicted.Takingthe specificexamples controversyin the literature concerningthe distribuof short wave diathermy and microwave diathermy, tion of the energywhen such low frequencies are both of which produce thermal energy and have used.o' AJchoughinitial repons indicatedthat the physicalpropertieswhich are well understood,curdeeperpenetrationof ultrasoundwith this frequency rent research has produced conflicting findings couldbe beneficialfor someclinicalapplications,later regardingthe distribution of the heat produced by reportsnote that.sincebeamdivergence increases at thesedifferentwavelengthsof electromagneticradiathis lower frequency,the intensity of the ultrasound tion in different rypes of tissueand by the different reachingdeepertissuesis very much reduced,possiappJicacors usedto delivertheserypesof electromag- bly to levelsthat are too low to producethe desired netic radiation.r-rFunherresearchcould clari,fiy d:re physiologicaleffects.Furtherresearchon the physical

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properties of this frequency range of ultrasound is neededto ascertainhow the energyis distdbutedand what clinicaleffectsit has.Iurther technicaldevelopments may also allow focusing of the beam while maintainingthe deeperpenetration. Another newer device.comoosedof a thermostatically controlledheating piate placedinside a wound dressing,has recentlybeendevelopedspecificallyfor the superficialdelivery of heat by conductionto the site of an open wound. This devicekeepsthe wound environmentwit-l-rina limited temperaturerangeat all times and is thus thought to promote wound healing. Iurther researchon the physical properties of this device,suchasits rangeof operatingtemperatureand its effecton local moisture,is neededto direct its clinical application. It is likely that in the future other physicalagents and devicesthat offer further control of energydelivery to patients will be developed. Ior example, devicesthat deliverheat for set amountsof time or at controlied but varying temperatures,devices that deliver electromagneticenergy with different pulse durationsand duty cyclesor with different ty?es of applicators,devicesthat apply stationary magnetic fields,or devicesthat apply compressionwith different pressuresor pressuregradientsor with alternative application devices, may be developed. As new devicesbecomeavailable,researchwill be neededto determinetheir physicalpropertiesand effectsand to ascertain whether they promote physiological changesthat produceclinicalbenefits.

Effects of Physical Agents Physiological

tions such as the use of ultrasoundor electricalcurrentsto facilitateftansdermaldrug deliveryand accelerate tissue healing or the use of thermotherapy, cryotherapy, or electrotherapy to control pain. Studiesconcemingthe effectsof physical agentson bacterialinfectionmay be particularlyvaluableat this time since many bacteriaare becoming resistantto availableantibiotics,necessitatingthe development of alternativetreatmentapproaches.Progressin these areaswill require examination of the physiological processesinvolved in both normal and abnormal function and the changesproducedin theseprocesses by the applicationof physicalagents. In orderto provide clinicianswith infomation that allows them to apply physicalagentswith more predictable results,future studiesshould seekto determine both the natureand the magnitudeof the effects of physical agents on physiological processesand attempt to determinehow theseeffectsvary with tissue t)?e and pathology.While prior researchgenerally evaluated the effects of physical agents at a macroscopiclevel, such as the effectsof heat on soft tissue extensibility or on arterial circulation, since current technologyalso permits examinationat the microscopiclevels of the cell, cellular components, and molecules,future researchshould also evaluate the physiologicaleffects of physical agentsat these levels.This will lead to an improved understanding of the mechanisms underlying the macroscopic effects of physical agents,thereby providing guidelinesforpredictingand controllingthe effectsofphysical agentson physiologicalprocesseswith greater precision.

Asenrs crinicar Apprication orphysicar {*-:gl T9:::1"1*:l.*: fT::1:: or physlcal agentsmay lacllltatery:l:il progress ln cltrucal practice,in order to optimize care, researchon tlre physiological effects and clinical uses of physical agents whose physical properties are already well understoodis also needed.Studiesshould examine the effectsof physicalagentson the physicaiproperties of tissue,such as muscleor tendon extensibility and cell membrane permeability, their effects on physiological processessuch as tissue healing and nerve conduction, and their effects on pathological statessuch as bacterialinfection. Iurther researchin these areas may delineate the magnitude of the effects produced by physical agents and the ideal treatmentparametento use to achievetheseeffects. Suchresearchwill also guide specificclinicalapplica-

Although researchon the physical properties and physiologicaleffectsof physicalagentswiil indicate which interventionsmay be effectiveand may clarily the mechanismsofinterventionsthatare known to be effective, clinical studies are needed to ascertainif interventionswith physicalagentsactually promote progress toward treatment goals. Clinical studies shouldalsoexaminethe effectsof differenttreatment parametersJsuch as method of application, treatment duration,intensity,and frequency.Ior example, when studyingthe effectsof electricalstimulationon musclestrengthening,a rangeof parametersmust be evaluated,including current waveform and parameters, electrodeplacement,and treatmentduration.In

Thrce . INTEGRAIING PHYSIC$

AGENTS INTO PRESENTAND FUTURE PRACTICE

addition, the effects of applying physical agentsto patients of various ageswith different pathologies and with symptoms of varied acuiqyshould also be evaluated.Thesetypes of studiesare neededto optimize the applicationof physicalagentsandmaximize the accuracyof predictionsconcemingthe natureand extentof the benefitsof suchinterventions. It is recommendedthat clinical studies examine applicationsofphysical agentsthat arein frequentuse at this time but in which the dataregardingtreatment efficacyandoptimaltreatmentparameters areinconclusive.Novel applicationsof commonly usedphysi cal agents and possible applications of recently developedphysicalagentsshould also be evaluated. For example. clinical studies on the effects of phonophoiesis and traction should be performed because,althoughtheseinterventionsare commonly used to treat local inflammatory conditions and symptomsrelatedto spinaldisc buigesor hemiation, respectively,the benefitofthese interventionshasnot yet been conclusivelyproven, and the optimal treatment parametersand patient presentationsfor their applicationhavenotyet beendetemined. Takingthe example of phonophoresis, studies should first attempt to ascertainwhether, when using the common curent application techniques,phonophoresis reducesthe impairments and functional limitations associatedwith inflammation. If phonophoresisis found to be effective,one ,houid then evaluate whether changingany of the treatment parametersl such as the ultrasoundduty cycle,intensity and frequency,drug type and vehicle,or treatmentduration and frequency,altersthe effects.Studiesshould also evaluateif the treatmentis more effectivedurine cerrain stagesof inflammation or for cenain typei und depthsoftissue.In the caseof traction,studiesshould determinewhether the common currentaDDlications are etfective.and if so, whetherchangingir"ut-enr parameterssuchas the hold and relax times, traction force,or treafnent duration alter the effects,or if the treatment is more effectivewhen used for patients with sl,rnptoms of different etiology, duration, nature,or distribution. Studieson the effects of specificphysical agents wili provide information to guide cliniciansin selecting physical agent interventions and treatment parametersfor different patients and in predicting more accuratelyand reliably the outcome of such interventions.However, in order to direct the selection of the ideal treatlent, studies comparing the

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effectivenessof different tueatmentoptions are also needed.Ior example,although current studiesindicate that ultrasound and electricalstimulation may facilitatethe closureof openwounds,and that electrical stimulation,cryotherapy,and thermotherapycan reducepain,until studiescomparingthe effectiveness of these interyentionsare performed,it will not be clearwhich treatmentsare most effectiveand should thereforebe chosenfor clinicalapplicationin patient care.

Precautions, andAdverse Contraindications, Effects Agents of Physical Although more researchon the benefitsof applying physical agentsin rehabilitation will help to guide treatment selection, studies on the specific contraindications,precautions,and adverse effects of physicalagentsare alsoneededto determinewhether currentprecautionsareappropriateand to ensurethat teatments with physicalagentsare appliedsafely.At this time, restrictionson the useofphysicalagentsare frequendybasedon expectationsof possibleadverse effects and prior common practice rad:Ierthan on evidenceof the propertiesand effects research-based of physical agents.This may fail to prevent some restrictthe unsafeapplicationsandmay unnecessarily use of safeand effectiveinterventions.For example, in the absenceof researchto rule out detrimental effects,and due to concerntllat the integrity of bone may be disruptedin someway by ultrasound,some authorsrecommendthat ultrasoundbe appliedwith particuiar caution to patients with osteoporosis,d Although this may reducethe risk of harm to patients with osteoporosis,it may also prevent them from receivingtreatmentthatmay be beneficial. Although researchon the contraindicationsjprecautions,andadverseeffectsof physicalagentsis necessary,it is difficult to perform studiesin theseareas that provide definitivedataapplicableto clinicalpractice. This is becauseit is not ethical to placehuman subjects at avoidable risk by applying treatments thousht to be unsafein order to determineif treatmeniwarnings are justified.Therefore,in vitro studies,studiesusinganimal subjects,and casereportson adverseeffectsareneededto clarify the potentialrisks associatedwith the applicationof physicalagents. A number of conditions, including pregnancy and malignancy,have generallybeen consideredto be contraindicationsfor the application of physical

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Directions for Fufitre Rescarch ancl Ayylication

agents.Although there is litde information on the effects of physical agents on these conditions, the ootential adverseeffects.such as fetal abnormalities or acceleratedgrowth or metastasisof malignanttissue,can be so detrimentalthat, without evidenceto demonstratethat suchapplicationsare safe,their risk is consideredto be excessivefor clinicalaoolicationor for researchusinghumansubjects.turther information regardingthe safety of applying physicalagents to patientswith *rese conditionsmay be particularly beneficialin clari$ing when physicalagentsmay be used,particularlyto control pain. However, in order to protect patients and clinicians, until research demonstrates definitively that applying physical agentsin the presenceof theseand other traditionally accepted contraindicationsis safe, clinicians must continue to practicewithin curent restrictionsand warnings. Studieson the dsksassociatedwith the aoolication of physicalagentsmay promote improviments in practiceby making applicationspreviously thought unsafeavailablefor ciinical use.Ior example,in the past,the presenceof metal in an areawas considered to be a contraindicationor a causefor cautionto the applicationof ultrasound.The reasonwas that, lacking specificresearch,it was thought that this agent may produce excesslvetemperature lncreasesin metal, as doesdiathermy,a previouslyavailabledeep heating agent.There were also concemsthat therapeutic ultrasound may loosen metal implants. Howeve! sincestudieshaveshown that ultrasoundis reflectedby, but doesnot heat,metal and that it does not loosen metal implants, ultrasoundmay now be appliedin areaswhere metal is present.Ior example, ultrasound may be applied to promote increased range of motion (ROM) in areaswhere drere is soft tissue shortening after the implantation of metal platesand screwsaftera fracture.v

METHODOLOGICAL CHARACTERISTICS RESEARCH OFFUTURE ONPHYSICAL AGENTS StudyDesign Case report Single-subject design Group design

The goal of most researchis to determinethe effect, or effects,of specificinterventionsasprecisely,definitively, and clearly as possible.Although this may appearto be a simpletask,it is fraughtwith both theoreticaland practicaldifficulties.Theoretically,it can be difficult to determinethe effectsof an intervention because,even if that interventionis consistentlyfollowed by a changein the subjects,one cannotbe certain that the interventionactuallycausedthat change. Ior example,if the applicationof traction is followed by a reductionin low backpain,one cannotbe certain tiat tlre tractionreducedthe pain since,in many indi viduals,iow back pain resolveswith or without the applicationof any treatment.Practically,it is particularly difficult to ascertaincauseand effect in clinical carebecausedifferentindividualsmay responddifferendy to the same inteffention, most interventions involve a number of components,and many patients progress,either toward or away ftom the goals of treatment, independentlyof the application of any intervention. Studies may be designed in various ways to attempt to overcome these problems and thus to detemine, correcdy and accurately, the effectsofinterventionswith physicalagentsto appropriatelyguidefutureclinicalpractice. Casereport The simplestform of researchis a casereport.A case report is a detailed description of an individual patient's cl.inicalpresentatioq the course of treatment, and the changesin clinical presentationthat occur during and generallyafter *rat courseof treatment. A casereport should include a thorough and complete descriptionof all aspectsof the patient's care and status, including which treatments were applied,when and how often they were applied,as well as the patient's age, gender,diagnosis,impairments, functional limitations and disabilitiesbefore, during,and after treatment. A casereport is generallythe first type of formal evaluation of a ffeatrnent approach that is performed. It is most valuablefor describingsuccessful methods for ueating various conditions when little other information is available.A casereportgenerally concernsthe applicationof a novel intervention for a common problem or the use of a common intervention for a novel application.The advantagesof casereports are that, when well written, they provide information about all aspectsof the patient's presentation and care in detail, and they require

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tics that can confound the interpretation of studies the investigator only to describe an individual's study, involving groupsof subjects.In a single-subiect presentation. Case reports do of treatment and course one are taken from measurements since all outcome any way. treatment to be changed in not requirethe between in status found any differences subject, they reports is that The primary disadvantageof case applyingand not appiyingthe intewention are likely only provide information about what was done to a to be due to the intewention.HoweveSalthoughsinpatient, patient what happened to that particular and gle-subject studieshavea number of advantagesover *re observed without clearlyindicatingwhat caused sincethey only evaluatethe responseof case repofts, certain which, if changes.Therefore one carrnotbe to an intervention,caution should a single individual any, of the intervention(s)in question causedthe generalizing the findingsof suchstudies in be applied observedchangesor if these changesoccurredindesubjects. to other oendendv of the interventions.Caution should also Studiesusing single subjectsare particularlysuitte observedwhen consideringapplying the findings of a casereport to other individualssincethe changes able for investigatingthe effectsof interventionson uncommon problemswhere largegroupsof subiects that occurredin the subjectof the report may have may not be availableand for analyzingthe effectsof beenuniqueto that individual. interventionson problemswhosenormal progression Singlecasereports can provide valuableinformation to guide clinical practice and further research. is so variableasto obscureany effectsof an intervention using a group design.However, in most situaWhen a number of casereportsdescribesimilar outcomesafter the applicationof a specificintervention, tions, comparing the effects of providing an interventionto onegroup of subjectsandwithholding this increasesthe likelihood that the intervention causedthe observedchangesand that it would cause it from anothergroupof subiectsmore clearlydemonsimilar changesin other individuals.This increases stratesthe effectsof that intervention and provides strongerevidenceto support its applicationto other the confidence with which the findings can be individualsin clinicalpractice. appliedto clinicalpractice.Singlecasestudieswhere treatmentis appliedand then withdrawn, and studies involving groups of subjects,some of whom receive Groupdesign When well-designed,studiesinvolving groupsof subthe intervention and some of whom do not, further jects usually provide the strongestevidencefor the strengthenthe proof of an associationbetween the effectivenessof an intervention.In general,the size treatmentand proposedeffect and improve *re qualand homogeneityof the groupswill havethe greatest ity of evidenceto justify applicationin clinical pracimpact on the qualiry of the findingsof a group study. tice. Large, homogeneousgroups of subjectsshould be usedwheneverpossiblein order to minimize the risk design Single-subiect A controlled study using one subject,whose status of failing to detect the effects of an intervention. When small, heterogeneousgroups are used, differwhen an interventionis appliedfor a period of time is encesbetween groups produced by an intervention comparedwith the status when the intervention is may be maskedby variabilitywithin the groups. not applied, provides more definitive information Ior example, if ultrasound is applied to a few aboutthe effectsof an inteNention than a casefeport. with tendonitisof varying degreesof acuity patients subjects, the intergeneral, for studies using single In and of varying tendonsand, after the treatment,no vention is appliedand withdrawn a number of times, differencesin pain or dysfunctionare found between andthe subject'sstatusduring orimmediately followthesepatientsand otherswho did not receiveultrawith the periods is compared ing the of application sound,the failureto detecta treatmenteffectcouldbe intervention was periods when the statusduring the due to the fact that (1) ultrasounddoesnot reducethe nor appleo. In contrast to casereports, single-subjectstudies pain or dysfunction associatedwith tendonitis, or that (2) the range of pain and dysfunction within can differentiatethe effects of time alone from the groups was greaterthan the range between the the effectsof the intervention under investigationwithgroups, or that (3) ultrasoundis effectivefor treating out the time and expenseof studiesinvolving groups only at certaindepthsor at certainstagesof tendonitis of subjects.Single-subjectstudiesalso eliminate the If this study was performedwith a largegroup differencesin initial status or individual characteris- acuity.

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of subjectswho all had tendonitis of the extensor carpiradialisbrevistendonin the acuteinflarnmatory stage,if *re heatment was effective,its effect will not be obscuredby variationswithin the groups of suolecls. Unfortunately,becauselargegroupsof individuals with similar characteristicsare difficult to recruit, many studies, particularly those involving human subjects,use small, heterogeneoussamplesand may thus erroneouslyconcludethat treatmentsare ineffective.Thereforewhen studieswith small,heterogeneousgroupsof subjectsfail to find treatmenteffects, while caserepods and single-subjectstudiesindicate that an intervention is effective,it is recommended that future researchreplicate these group studies usinglarger,more homogeneoussamples. Although studies using large, homogeneous groupsof subjectsoptimize the probability of detecting small, statisticallysign.ificanttreatment effects, the clinical significanceof theseeffectsmust also be taken into account when consideringapplying the findings to clinicalpractice.For example,although a study may find that applying heat before stretching the knees of patients who have had a total knee arthroplasty results in a statistically significandy greatergain in flexion ROM than stretchingwithout prior heating,if the differencein ROM gainsis only a few degrees,this may not be clinicallysignificantif it doesnot affectpatient function. A slight acceleration of recoverymay also be statisticallysignificantwhile not justifying the use of an intervention in general clinicalcare.Ior example,evenif applying traction is found to decreasethe recoverytime from a low back injury from 40 daysto 39 days,in most casesthe cost of applyingthis treatmentwill not be justifiedby this smalleffect.

Subjects In vitro (materials, tissue, cells) Animals (nomal, disease model, true disease) Humans (normal, patients)

Having selected the appropriate study design, basedon the nature of the effect being studied and the quality and availabilityof prior studies,an investigator must also select suitable research subjects. Subject selection will depend on the nature of the effect being studied, the qype of outcome data

desired, and the availability of different types of suDlec$. tissue,cells) In vitro(materials, The term in vitro, meaning "wi*rin glass," is used to describestudiesthat are carriedout in a containeror in a test tube ratherthan within a living organism.In vitro studiesuse various nonliving matedals or cell culturesassubjectsand canbe usedto evaluatemany of the physical properties and effects of physical agents,including the penetrationand absorption of different types of energyby different materialsand the effectsofthese typesofenergy on thesematerials. In vitro studies using biological materials can also yield information about the effectsof physicalagents on the physical or physiologicalpropertiesof these materials,suchasskin or cellmembranepermeability, tissueextensibiliry or cellviability. The advantagesof in vitro studiesarethat they can generally be replicatedaccuratelyand they permit close control of subjectand intervention variabiliry. However, although in vitro studies may provide information regardingthe effectsof physical agents on the physicalpropertiesof tissue,cautionshouldbe exercisedin applyingfindingsofthese studiesdirectly to the more complexsituationof a patient.Ior example, althougha cell grown in agarin a Petri dish may be killed ormaygrowmore rapidly when an electrical currentis applied,becauseof differencesin temperature, pH, tissueresistance,current density,chemical environment,or other factors,this samerype of cell may not respondin the samemanner if an electrical cuffent is applied to it when it exists in an open wound in a patient. Some of theselimitations of in vitro studiesmay be overcomeby using animalsas 'acerr.h

c,,h;e.r.

(normal, Animals disease model, truedisease) The term in vivors usedto describestudiesthat are cardedout within a livingbody.In vivo studiesusing animalsas subjectsallow examinationof the effects of physicalagentson the physicalpropertiesof tissue within a normal physiologicalenvironment.This is necessarybecausenormal physiological processes may alter the effectsof physicalagents.For example, a thermal agentappliedto live tissuewith an intact, responsivecirculationwill have lessimpact on tissue temperaturethan the samethermal agentappliedto the sametype of tissuein vitro, with no circulation. The circulatory system will bring blood from o*rer

Three o INTEGRATING PHYSICAL AGENTS /NTO PRESENT/ND FUTURE PRACTICE

areasto cool the heatedtissue.This responsewill be exaggerated as the tissuewams up and vasodilation occurs.The effectsof physicalagentson physiologicalprocesssuchascirculation,heartrate,or temperature, may also be evaluatedby in vivo studieswith

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circulation,andmay be usedto investigatethe effects of interventionson experimentallyinduceddysfunction such as pain; however, caution must be usedin applyingthe findingsof suchstudiesto patientswith pathologybecausethe effectsmay be differentin the rnimel cr,hiertc presenceof pathology. Normal,healthy animalsmay be usedto study the For example,although electricaistimulation may effects of physical agents on normal processesor not increasemuscle strength more effectively than characteristics suchastemperatureor circulatoryrate, exercisein normal subjects,it has beenfound to augwhile animalswith pathology can be used to study ment strengtheningwhen applied to patients after the ' effect(s) of physical agents on pathology or kneesurgery Studiesusingpatientscanprovideinforimpaiments such as muscle shortening,soft tissue mation concerningthe effectsof interventionswithin injury, circulatoryimpairment,or pain. In addition to the context of pathology,and can aiso provide inforallowing for evaluationwithin the context of a commation about changesin subjectivecomplaintsand plete physiological system, studies using animals objective impairments, functional limitations, and allow the investigatorsto perform proceduresand disabilities. take risks that may not be ethicai with human subStudiesusing human subjectshave a number of jects.Studiescanalsouserelativelylargesamplesizes limitations, includingthe difficulty of recruitingadeat lessexpensethan with human subjectsand control quate numbers of subjects;having limited control many potentially confoundingvariablessuchas subovervariabiliryin subjectcharacteristics suchasprobject activity level, age,gender,and diet. Nonetheiess, lem severity and duration, subject age, and subject the results of animal studies should be aonlied to gender; and having limited control over subject human patientswith caution becausedifierences behaviorssuchas activity level, diet, and other med'ical in human characteristic$such as body s\ze, body interventions.There are also ethical constraints composition,skin thickness,or normal temperature, limiting the natureof the proceduresthat can be permay alter the effects.Studiesusinganimalsalsogenformed on human subjects.In general,procedures provide erally cannot information concerning the that may causeharm or discomfort,such as a tissue effect of interuentions on the subiects' functional biopsy or the applicationof a physicalagentin a cirfimitationsor disabilities. cumstancepreviously contraindicated,may not be performedon human subjects,and informed consent (normal,patients) Humans mustbe obtainedftom all human subjectsbefotetheir may Studiesusing human subjectscan yieid information inclusionin a research study.Theserestrictions regardingthe physiological effects of interventions limit the ability to determinethe mechanismof an wi*rin the human body and their effects on the observedeffect and prevent appiication of an intersequelaeof pathology including impairments,funcvention in a blindedfashlon. tional limitations, and disabilities.The human subjects used in researchmay either be patients with Gontrols pathologyor subjectswithout pathology.Using indi vidualswith pathologyis generallypreferredbecause Becausechangesin subjectscan occurwhether or not this providesinformationthat is more readilyapplica- any interventionhas been applied,in order to deterble to other patients.However, since there may be mine whether observedchangesare causedby an limited accessto subjectswith problems of similar intervention, the outcome of subjects who have and severiqy, as well as financial and ethical conreceivedthat intervention should be comparedwith rypes straintsto applying or withholding potentially effec- the outcome of subjectswho have not receivedthat tive carefrom patients,many studieson humansare intervention. The subjectswho do not receive *re performedusingnormal subjects. intewention beingevaluatedareknown ascontr\ls. Studiesusing normal human subjectscan provide When appropriatelyselectedand treated,control information about the physical and physiological subjectscan control for the effectsof chance,normal effectsof interventions,suchastheir impact on tissue progressionof the outcomevariable,and nonspecific temperature,tissuelength,musclestrength,or blood effects of treatment. It is particularly important to

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'14 . Directiorrs for Ftttute Reseatch and ApVlication

control for tlese effectswhen evaluatingthe impact of physicalagentsin rehabilitationbecausemany of the problemstreatedin rehabilitationmay vary without any intervention and tend to resolveover time, andbecausemost of the treatmentsorovidedbv rehabilitation clinicians have a variew of nonsDecific effects.Forexample.low backpain canvary in location from one day to the next, with no clear cause, and canvary in severityamongindividuals;however, for most individuals, acute low back pain resolves within 6 weeks whether or not anv treatmentis Drovidpd. Nonspecificeffectsof tuearmenr includepaying attention to the patient, which may increasethe patient's motivation; monitoring progress, which may improve the patient'scompliance;and touching the patient, either directly or with a device,which may provide a sensorystimulus to block pain transmission,whether or not any type of energyis being delivered. Without the use of appropriatecontroisit is diffi cult, if not impossible,to determine if the changes observedin subjectswho received an intervention were causedby that intervention.Ior example,if it is found that, in a group, most subjects'low back pain resolveswithin 6 weeks when a heatment such as traction hasbeenapplied,it cannotbe concludedthat their progresswas due to *re applicationof the treatment rather than being the normal recoverypattem for this problem unlessa similar group of individuals with similarsymptomsandno treatrnenttook significandy longer to recover.A treatment can be considered effective only if subjects who received the treatment show greateror more rapid improvement than control subjectswho did not receivethe treatment. Therearemany differentways to treat controlsubjects who are not receiving the intewention being evaluated.Although itmay be simplestandmost convenient to provide thesesubjectswith no treaftnent, this is not recommended.If the control subiectsare not provided with the attention and sensations associatedwith *re active treatment. then onlv the effects of chance and normal progression.not the nonspecificeffectsof treatment,will be controlled for. Treatmentswith interventionsthat haveno direct physiologicaleffectscan yield as much as lorry percent improvement in outcome, panicularly when subjectiveoutcomemeasuressuch as pain are used. Thereforeif the effectsof the interventiongroup are comparedwith those of an untreatedcontrol group,

the intervention will probably appearto have been effective even when the effectsmay have not been specificto that intervention. In order to control for nonspecificeffects of an intervention,it is recommendedthat control subjects receive an alternative intervention that aDDearsas similaraspossibleto the inrerventionbeingissessed but that is known, or thought, not to affect the outcomebejngevaluated. Suchaltemariveinterventions are known as placebos. When researchingthe effects of physicalagents,it is recommendedthat placebos consistof applyingthe treatmentin the normal manner,but wi*rout del;ery of energy6y the device. Ior example,a placeboultrasoundtreatmentmay be given by applying a transmissionmedium to the treabnentareaand then placingthe ultrasoundtransducer on the areaand moving it within that areafor the same amount of time used for the active treatment group. The differencewould be that, for the activetreatment,ultrasoundwas deliveredto the subject, whereas for the placebo treatment, no ultrasound was applied. Similarly, a placebo hot pack treatment could be applied by using a pack at body temperatureinsteadof a heatedpack.In both of these examples,the activeand placebotreatmentsare similar with regardto the preparationfor applicationof the treatrnent,the amount of attention from the person applying the intervention, and the amount of time the subiect receivedcare.Thus if a difference in outcome is found between those receiving the placebo treatment and those receiving the active treatment,it is likely that this differenceis due to tl:.e intervention being studied rather than being a nonspecificeffectof providingtreatment. In orderto determinethe effectsof an intervention most accuratel, it is recommendedthat neither the subjectsof the study nor the individualsapplyingthe intervention know whether an active or a placebo treatment is being applied.This is known as doubleblindapVlication. Aphysicalagentmay be appliedwith a double-blindplacebocontrol if it doesnot produce any identifiable sensationin the subject and if the deviceproviding the ffeatment appearsto be delivering energy even when it is not. Ior example, low-intensity ultrasoundmay be appliedwith a double-blindplacebocontrolif a devicethat operatesnormally is used for the active ffeatment and another device modified to produce no output, although it appearsto operatenormally, is usedfor the placebo treatment.The two devicesshouldbe markedfor dif-

ThTee O INTEGRATING PITYSICAL AGENTS INTO PRESENT AND FUTURE PRACTICE

ferentiation;however,t}rekey to their identity should be concealedfrom the investigatorsuntil all intervention and data collection have been comDleted. Because thispreventsboth the subjects andthe investigators from knowing which device is active and which is inactive,it will eliminatebiasduringapplication of the interventionand datacollection. If the physical agent being evaluatedproducesa distinct sensationin the subjects,such as the sensation of heat from a hot pack or the sensationof a pull from traction, or if deactivateddevices to prevent knowledgeof the personapplyingthem arenot available,then the interventionmay be applied only in a single-blindmanner.Ior example,if only one device is available,low intensitiesof ultrasound or shortwave diathermy (SWD)that do not producea sensation of heat may be appliedin a single-blindfashion, with blinding of the subjectsonly, by setting the deviceto the desiredintensity for the activetreatment group and not tuming it on for the placebotreatment group. Hot packs,which producea sensationof heat in the subject,may be appliedin a single-blindfashion, with blinding of the investigators,ifhot packsare used for the active ffeatment group and unheated packssimilar in appeatanceare usedfor the placebo ffeatment group, and if the investigatorswear heatproof glovesso that they cannotfeel the temperature of the packs. Interventionsthat producedistinct sensationsand that require specific behaviors by the individuals applying them, such as compression,traction, most forms of electrical stimulation, or ultrasound or diathermy at intensitiesthat producea sensationof heat, cannotbe deliveredin a blindedmanner.When attempting to assessthe effects of these types of physicalagents,lower energylevelsofthe sameintervention or other interventionsrecommendedfor the sameproblemmay be appliedto the controlgroup for compadson.Ideally, in such circumstances, in order to control for confoundingeffectsof changingmultiple variables,the intervention applied to the control subjectsshouldfeelassimilaraspossibleto the active treatment,requirea similarftequencyand durationof application,and involve a similar degreeof personal attentionfrom the individuaJ applyingit. In order to avoid, or at leastminimize, confounding effectswhen usinghuman subjects,double-blind placebocontrolsshouldbe usedwhen possible;when dris is not possible, single-blind placebo controls should be used. Only if neither double- nor single-

451

blind applicationis possibleshould placeboor active alternativetreatmentsbe applied without blinding. When using animal subjectsor performing in vitro studies, blinding of the subjectsis not necessary; however, blinding of the investigatorsapplying the intervention and collectingthe outcome data is recolTunenoeo. Because,unlike most other rehabilitationinterventions suchas exercise.or ioint or soft tissuemobilization, many physical agents can be applied readily with double-biind placebocontrols, future research on the effectsof physicalagentsshould use doubleblind controiswhenever possible.This will support the conclusionthat differencesin outcome between subjectsreceivingan activetreatmentand controlsare due to the treatmentratherthan to someother aspect of careand will allow therapiststo apply the findings of suchstudieswith confidence.In contrast,if appropriate controls are not used, although much time, effort, and expensemay be expended, the study resuitswill not readily improve patient care.It will not be known whether the treatmentsbeine evaluatedareeffectiveandshouldbe usedwith oatilnts.or whetherany observedchanges in subjectitatuswere the result of chance,normal progression,or nonspecific effectsof the intervention.

0utcome Measures Reliability Once the investigatorhas selectedthe appropriate study designand controlsfor evaluatingthe effectsof an intervention using a physical agent, appropdate measuresof the outcome must also be chosen.The outcomemeasuresselectedshould be reliable,valid, and clinicallyrelevant.A measureis consideredto be reliable if the same or a similar result is produced when Lhemeasureis repeated.Ior example,goniometric measurementof activekneeflexionROM may be consideredreliableif the sameor a similaransleis reportedwhen activekneeflexionROM is meas-ured rcpeatedly. The reliability of a measuremay vary for different applicationsor populationsand with applicationby the same or another individual. Ior examole. a numericvisualanalogscalecompletedby the subject may be reliablefor the assessment of pain severiryin adultsbut unreliablewhen usedfor the assessment of pain in infants or young children or for the assessment of kneeROM in subjects. Sincemost measures

452

44 . Directiors fot Futnte Researchand AVVlicatiofl

producemore similar resultswhen reappliedby the same individual (known as intrarater reliability) rhan when reappliedby different people (known as lzterraterreliabiii it is recommendedthat measurements be performedby only one individual,or by as few as possible,duringthe courseof a researchstudy.Iuture researchshould only use measureswhose reliability in the population being testedhas been proven, and the measures' reliability should be clearly documented"inall researchreports. Validity In contrastto reliability, which relatesto the reproducibility of a measure,validity relatesto its usefulness and the degree to which it representsthe property it claims to measute.Iot example, for a questionnaireto be a valid measureof disabiliry in a population, it must actually measurethe reduced ability of this population to perform normal activiin differties. Vadous forms of validiry are assessed ent ways, such as correlationwith other measures of the same characteristic,logical analysisof how the conterfif a measurerehtJs to the characteristic it claims to measure, or evaluation of how accurately the measurepredictswhat it claimsto predict. Measuresmay be valid by one standardbut not by another.For example,althoughmeasuresof abdominal strength and lumbar flexibiliry may have high content validity as measures of low back pain, becauseit appearslogical that they would be related to low back pain and may be predictorsof future low backpain,they arenot consideredto havegood criterion-relatedor predictivevalidity becauseit has been found that abdominal sftength and trunk flexibility do not correlatewith self-reportsof low back pain and do not predictwho will havelow backpain in the future.1o Clinicalrelevance As well asbeingreliableand valid, outcomemeasures usedin future researchconcerningthe effectsofphysical agentsshouldrelatedirectlyto the goal(s)oftreatment and should include measuresof the effectsof interventionson impaiment, functional limitations, and disability. In conkast to prior research,which focusedprimarily on the effectsof physicalagentson impairmeng examining, for example, the effect of thermotherapyon soft tissuelength and extensibility or the effectsof traction or electricalstimulation on

oain. future studiesshouldalsoevaluatethe effectsof these interventionson functional outcomessuch as walking speed,lifting capacity,or sitting tolerance. Futureresearchshouldalsoevaluatewhetherthese interventionsreducefunctionallimitations.Ior example, researchshould evaluatewhether spinaltraction facilitatesthe sublects'retumto work, promotestheir ability to shop independendy,or acceleratestheir retum to sportingactivity.Examplesof possiblestudies on the effectso[ physicalagentson functionallimitations and disability includeevaluatingthe effectof thermotherapy on ambulation distance,ambulation velocity,and the time requiredto retum to functional independenceafter total kneearthroplasryor evaluating the effectoftraction on the time requiredto retum to work and the level of work retumed to in patients with low back pain and radiculopathy.Data ftom such studieswill allow prediction of functional outcome in responseto treatment,and may be used to guide future practiceand to support reimbursement for treatment, In orderto provide further supportfor usingphysical agents in rehabilitatiorl future studies should demonstratenot only that physicalagentsoptimize the achievementofpatient goalsbut alsothat they do so in the shortest amount of time and for the lowest cost. In order to achievethis, researchevaluating the cost effectivenessof usingphysicalagents to achievespecific functional outcomesis required. In order to evaluatethe potential costs and benefits of an interventionrealistically,the costsof providing the intervention should be compared with the potential savingsassociatedwith reducingthe duration and severiqzof a patient'sdisabiliqyand handicap. Potential savingsmay include reducingloss of incometo the patient,reducingcoststo the employer with replacinga memberof the workforce, associated and avoiding costsassociatedwith providing further careto the patient.For example,providing tractionto patients with low back pain for 10 visits may cost $500; however, if it is shown that *ris accelerates their return to work by an averageof 1 week, this treatment can be consideredcost effective if the costs to those patients, their employers,and their insurancecarriersassociatedwith not working for 1 week are greater than $500. Studiesdemonstrating the cost effectivenessof interventions can provide strong support to justify reimbursementfor those interventions .

Thtee O INTEGRATING PHYSICAL AGENTS INTO PRE SENT AND FUTURE PRAjTICE

Reporting In recentyearstherehas beena growing interestand support for the practiceof evidence-based medicine. In this context,a number of systematicreviewsof the literatureandmetaanalyses havebeencarriedout and published.Thesetypes of reportsattempt to evaluate and synthesizethe findingsof prior direct studiesin a particulararea.A systematicreview ofthe literatureis comprisedof a systematicsearchfor publishedstudies concerninga specificquestion,evaluationof the quality of the studiesfound, and a summaryof their findings.A metaanalysisgenerallyalsocombinesdata from all randomizedcontrolledtrialsto determinethe efficary of an intervention. Ior example,there are recentmetaanalyses of the studiesconcerningthe use of spinaltraction for the treatmentof low back pain and of the studies concemingthe use of lowlevel laser *rerapy for the treatment of osteoarthritisand rheumatoid arthritis. Systematicreviews of the literature and metaanalysesconcerningthe efficacyofphysicalagentsfor various rehabilitation applicationsgenerally report that the evidence does support curent practice. However,in al3rst all areasthe researchis criticized for insufficientnumbersof subjectsstudiedand poor descriptionsof the interventionsused.This limits the conclusionsthat canbe drawn. Ideally, future studieswill include larger numbers of subjec*.AIso,itis essentialthat future studiesdescdbe fully all aspectsof the subjectsand of the intervention being evaluated.Subjectdescriptionsshould include dre number of subjects,their averageage and age range, their sex distributioq the types of problem being treated,severityand acuity or duration of the problem,and any other featuresthought to be pertinent to the specificquestionat hand. Descriptionsof the interventions should include the nature of the physicalagentusedand all treatrnentparameters.Ior example,in studies of the effect of ultrasound on wound healing,the subjects'averageageand agerange and sex distribution should be given. Information aboutwound etiology,size,and stageshould also be provided, and the ultrasoundfrequency,intensity, duty cycle, effective radiating area and treatrnent time, as well as the ffeatment area,should be clearlynoted. This type of reporting will allow one to draw clearer conclusionsregarding the efficacy of physical agents and the necessaryor optimal fteaftnentparametersto producethe bestclinicaleffect.

453

CONCLUSION Civen the advantagesand limitations of different study designs,subjects,controls,and outcomemeasures, various types of researchare neededto gain a full understandingof the effects of physical agents andto optimize their clinicalapplicationin rehabilitation. If future researchfollows the guidelinesprovided in this chapter,the effectsof physical agents, the mechanismsunderlyingtheseeffects,and the critical variablesfor producingthem will be more thoroughly understood,increasingthe effectivenessand predictabiliry of applying physical agents while potentially decreasingthe costs of patient care.It is alsoexpectedthat, althoughfurther researchwill provide many answers,it will also producemany more questions,particularlywith regardto optimizing the effectivenessof treatment.It is likely that, as particular interventions are found to be effective, further research will be needed to determine when, to whom, and how these interventions should be applied to obtain the best results;if these interventions are more effective than availablealternatives; and if they are more effectivewhen usedin conjunction with other interventions. Similarly,if studies show that an intervention is not effectivefor a particularapplication,further studies to investigateif it would be effectiveif appliedin a different manner, with different treatment parameters, or to subjectswith different charactedsticsor problems,may still be valuable.Thereforealthough the clinicalapplicationof physicalagentsin rehabilitation at any time should be guided by the available research,in order to continuallyimprove the quality of careprovidedto patients,it is essentialthat further research be performed and that clinicians stay informed of the findings of thesestudiesand modib/ their practiceaccordingly. Chapter Review Iurd:rerresearchconcerningthe useofphysical agents in rehabilitation is neededto increase*re development of evidence-basedclinical practice.This will improve the outcomesof treatmentand supportcontinued reimbursementfor such treabTrent.Research conceming the physical properties, physiological effects, clinical applications,and adverseeffects of physicalagentswill help to elucidatethe mechanisms by which physical agents exert tlretu effects, clarify

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'14 . Dbections for Fsture Researchand Application

the nature of theseeffects,and detemine the conditions under which these effects are optimized. Different study designswith varying degreesof complexity are neededto evaluatedifferent applications of physicalagents.Casereportsand single-subject, conrrolled studiesareneededro describe andevaluate treatments that appear to be clinically effective. Thesestudiesshouid be followed by conirolledstudIes wlrn groups or suolectsLn oroer to ascertatn whetner tnerr rrnorngscan Deapplredto otner rndlviduals, to clarify the nature and magnitude of,the specificeffectsof differentinterventions,and to identify idealtreatmentparameters. In order to provide information about the microscopic,macroscopic,and functionalimpactsof physical agents, future researchwill also need to use various qypesof subjects.Studiesusing patients as sublectswill provide information that iray be most reaiily applied 'and to other patients;however,2ue to the pract;al ethical limitations of performing researcn on people,parucutay wnen uslngpanents.

animal inuitrosrudies. reseaich. andsruire" using

normal human subjectswill be neededto evaluatethe effectsf physicalagentswhere theremay be risk to a patient from receivingthe intervention being evaluprocedures ated or ftom undergoingthe assessment being used. Future researchwill also need to use appropdate, and ideally double-blind, controls in oiaer to produce t".uit, fro- which conclusion, regarding ideal treatments can be drawn. This researchwill alsoneedto evaluatethe effectsof interventionswith reliable,valid,and functionallyrelevant

on patients' functional outcome will be. The reader is referred to the Evolve website at http://evolve. elseviercom/Cameronfor study questionspertinent to this chapter.

References andpulsed l. CoruadiE,?agesIH: Effectsof continuous mrcrowaveirradiationon distributionof heat in the qlucea. region of miniprys. S,and Med2):59-62 I Rehabil ioqo z. v"iri"rn, rut.orrerK,crawfordsJ:A comparison of tissueremperature followingnvo sho.nuu" diathermy physiother t977. techniques, CanidaZgltl,Zt-25, A et al:Heatingrabbit 3. Fadilah& PinkasJ,Weinberger joint by microwaveapplicator, ArchPhysMed Rehabil . 68(10):710-71,2,1987 of unfocused laserlight into the 4. KoLariPJrPenetration skin,AtchDetmatol Res 277:342'344, 1985. _ Med 5 Low levellasertherapy:a revr.w,Lasets Ilg ,?l' sL-i^4:141' r50' r9B9' . tsradnock 6. B,LawHT,Roscoe K:A guantltative compar-

iff:|.:'#"'ff'il""#ffi'1il:'fftr"fi#il:1";

tlerupy,,)i. the treatmentof acute ankle sfrains, physiiheraryBI(7):78-84, I9g5. VJ:Comparison 7. WardAR,Robenson ofheatingofnonlivingsoft tissueproducedby 45 kHz and 1 MHz !requencyultrasoundmactines, J OnhoySVonPhysTher 23(4):258-266' 1'996. B.S_weitzer In HecoxB, MehneabTA, RW:Ultrasound. Tettfot WeLsberg J,eds:Plysic^lAge\ts:A Col\Fteheasite Phvsical rheravkts' EastNorwalk'cl 1993'Appleton&

i|llj"^ r,r+-^-^..-., n "t outcomemeasures.ru,u,",","",J'J[Ii"i.; ;i ::Tt"",ffin::,Ai,1iTtrJi#',Truj will benefit from treatments with particular physical agents, how these treatments should be applied to optimize their eftectiveness,and what the nature and magnitude of the benefits of such interventions

Med Rehabit63:371-373.1982. 10. IacksonAW. Morrow IR. Brill pA et al: Relarionsof sitiesrsto low back pain in adults, up and sit-and-reach I OtthopSyonPhysTher27(I):22-26,7998.

Glossaryof Commonlv UsedTerms ., abscess:A localizedcollectionof pus absolute refiactory periodr Time after an action potential during which another action potential cannotoccul absorption: Conversionof energyincoheat accessory motion: The motion that occurs bewveenjoint surfacesduring normal physiologicatmouon action potential: Depolarizationof the nerve membrane;reversalof the transmembranepotential active motion: The movementproducedby contraction ofthe musclescrossinga joint acute pain: A combination of unpleasantsensory perceptual,and emotional experiencesthat occur in responseto a noxious stimulus provoked by acuteinjury and/or disease adhesion: Abnormal joining of partsto eachother adverse effect: Any result of a treatrnent that is undesirable adverse neural tension: The presenceof abnormal responsesproducedby peripheralnervoussystem structureswhen their rangeof motion and stretch capabilitiesaretested alternating current: A continuousflow of charged particlesin altematingdirections

amplitude: Electricalcurrentamplitude.This may be a measureof the currentor the voltase analgesia:Absenceof sensrbility to pain anode: Positivelychargedelectrode atrophyr Wastingor decreasein *re sizeof a muscle or an organ attenuation: Decreasein energyas radiation passes through a material buoyanry: A force experiencedas an upward thrust on the body in the oppositedirection to the force ofgravity capacitance:The ability to store charge; generally measuredin larads capsular pattern: The specific combination of motion loss that is causedby shortening of the joint capsulesurroundinga joint carotid sinus: The dilated ponion of the internal carotid artery *rat contains the pressoreceptors tlat are stimulated by and stimulate changesin blood pressure;locatedin the antedorneck cathode: Negativelychargedelectrode cavitation: The formation, growth, and pulsation of gasorvapor-filledbubblescausedby ultrasound chemotaxis: Movement in responseto a chemicai concentrationsradient

456

Clossary of Commody Used Tetms

chronaxie: The minimum pulse duration that will excitea nervefiber when a stimuluswith an ampli tude of twice rheobaseis applied chronic pain: Pain that does not resolve in the usual time it takes for a disorder to heal or that continues beyond the duration of noxious stimulation collagen: The main supportive protein of skin, tendon,bone.cartilage, andconnective tissue compression: The applicationof a mechanicalforce *rat increasesthe externalpressureon the body or a body part conductivity: A material'sability to propagatecunenq conductivity is inverselyproportional to resistivity connectivetissue: Tissuethat bindstogetherandsupportsthe variousstructuresof the body; madeup of fibroblasts,fibroglia,collagen,andelastin consensualresponse: A reflexoccurringon the oppositesideof the bodylrom the point of stimulation contractu(e: Shorteninsof soft tissue contraindication: Any condition that renders a particularform of treatmentundesirable or improper convection: Heat transferby circulationof a medium of a differenttemoerature .,D; cryother5-py: I he therapeuticuseof cold cuff€nti The rate of flow of chargedparticles;generally measuredin amperes debridementr The removal of foreisn matter and tissuefrom a lesion deviralized diathermy: (Creekfor "through heating")The application of shortwareor microwave frequencyelectromagneticenergyto heat tissues direct cuffent: An uninterrupted flow of charged particlesin one direction disability: inability to perform a task or the obligations of usual roles and typical daily activitiesas the resultof impairment disc herniationr Disruption of the annularfibers of the soinaldisc dwty cycler The proportion of the total treatment time tlat energy is being delivered; generally asa percentage or raLio expressed edema: The presenceof abnormalamounts of fluid rissuespaces of the body in the extracellular elasticdeformation: The elongationproducedunder loadingthat reversesafterthe load is removed electric field: The force field between elecfiic charges electrode: The medium or objectusedto conductan electricalcurrentto an objector a person

electromagneticradiation: Perpendiculadyoriented electricandmagnericfieldsthatvaryovertime embolus: A clot or other plug brought by the blood from one vesselto anothersmallerone to obstruct the circulation end-feel: The qualiry of the resistancefelt by the climotion nicianat thelimit of passive endogenous: Originatingfrom the body epiphysis: The end part ofa long bonethat is formed from a secondarycenterof ossificationand that is separatedfrom the main portion of *re bone by cartilageuntil skeletalmatudty is reached erythema: Rednessof the skin causedby capillary congestron exogenous: Originatingoutside*re body extravascular: Outsidethe vessels exudate: Iluid that has escapedfrom blood vessels and beendepositedin tissuesor on tissuesurfaces; has a high concentrationof protein, cells,or solid materialderivedfrom cells fibroblast: Cell that producesconnectivetissue flaccidity: An extremetype of musclehypotonicity in which no muscle tone is detectable;usually associatedwith paralysis ftequenry: The number of eventsper unit of time functional limitation: The inability to perform the tasksor behaviorsrecogrizedas essentialcomponentsof daiiy life galvanic current: Direct current galvanotaxis: Movement in responseto an electrical charge gate control theory of pain: The hypothesis that pain may be relieveddue to modulation of nociceptor transmissionat the spinal cord by largediametersensoryfiber activation handicap: The socialdisadvantage of a disability hematoma: A confinedeffusionof blood hernorrhage: Copious escape of blood from the vessels histamine: An vasodilation

endogenous amlne trrat causes

hydrostatic pressure: The pressure exerted by a fluid on an immersedbody hydrotherapy: The therapeuticapplicationof water hypertonicityr Abnormally increasedlevels of musby voluntary cletone that arenot readilydecreased relaXanon hypotonicilz: Abnormally decreasedlevels of muscletone that arenot readily increasedby voluntary tensins

Glossaty of Commody UsetlTerms

impairment: Any lossor abnormalityof anatomical, physiological, or psychological structure or tuncuon impedance: The sum of resistanceand capacitance inflammation: Initial tissue reaction to tissue injury infrared radiation: Electromasneticradiationwith a frequencyof l0Il to 10laryJes persecond intensiqz: Amount of power per unit area; usually expressed in Watts/cm2 intravascularr Within the blood vessels in vitro: "ln glass";study performedoutsideof a livmg orga sm in vivo: "In life"; study performed on a living orgarusm ionizing radiationr Electromagneticradiation that can break molecular bonds to form ions (e.g.,X

457

nonionizing radiation: Electromagnetic radiation that cannot break molecular bonds to form ions (e.g.,microwave,shorwave, infrared,visiblelight, ultravioletA andB) Ohm's law: voltage= currentx resistance oncotic pressure: The osmotic pressureof colloids : - ^ - ^ l l ^ r - ]^ l - . . - - ^ -

opiopeptins: Croup of endogenousneurotransmittersthat haveeffectssimilarto thoseof exosenous opiares osmotic pressure: The pressurethat brings about diffusion between fluids with different concentranons pain: An unpleasant sensory and emotional experience associatedwith actual or potential tissue damage or described in terms of such damage paralysis: A state in which no active muscle coniontophoresis: The transcutaneousdelivery of ions traction is possible; the loss of voluntary into the body for therapeuticpurpose using an movement electricalcurrent paresis: Lessseverereductionof activemuscleconischemia: Deficienry of blood in a part due to contraction than paralysis;only weak muscularconstrictionor obsffuctionof a blood vessel traction canbe elicited laser: Acronym for light Amplification by passivemotion: Movement producedentirely by an Stimulated Emission of Radiation; monochroextemal force without voluntary muscle contracmatic, coherent,directionallighr tion by the subject leukocyt?White blood cell; inilude a variety of cell periosteum: Connective tissue covering all types-neutrophils, basophils, eosinophils,ly,mbones phocytes,andmonocytes peripheral vascular disease: Ceneral term for dislymph: Transparentfluid found in lynnph vessels; easeofthe peripheralarteriesorveins;usuallyused consistsof liquid and a few cells that are mostly ro describe narrowingoI the arteries lymphocytes phonophoresis: The application of ultrasound lymphedema: Swellingof subcutaneoustissuesdue with a topical drug to facilitate transdermaldrug to the presenceof excessive lymph delivery magnetic field: The force field between magnetic physical agent: Various forms of energy and poles materialsapplied to patients and their means of margination; Adhesionofleukocytesto blood vessel application walls duringan earlyinflammation physiological motion: The motion of one segment modality: A physicalagent ofthe body relativeto another monocbromatic: Of one color piezoelectric: The property of producingelectricity muscle tone: The amount of resistanceto passive in response to the application of mechanical stretchof a muscle;underlyingtensionin a muscle pressure and of contracting and expanding that servesastlle backgroundfor contraction in responseto the application of an electrical myelin: A fatty insulating covering present at intercunent valsalongmost newe fibers plastic deformation: The elongation produced nerve conduction velocity: The speed at which under loading that remains after the load is actionpotentialstravelalonga nerve removed nociceptor: Specificnerve ending that respondsto power: The amount of energyper unit time; usually painful stimuli measuredin Watts

Glossaryof CommonlyUsedTetms

458

precautioni Any condition for which special care shouldbe takenpriorto renderinga particularform of treatment psoriasis: A common benign, acute, or chronic inflammatory skin diseasecharacterizedby bright red plaques with silvery scales,usually on the knees, elbows, and scalp, associatedwith mild itching pulsed shortwave diathermy: The therapeuticuse of pulsedshortwaveradiationin which heat is not the mechanismof action radiation: Exchangeof energy directly without an interveningmedium range of motion: The amount of motion that occurs when one segmentof the body moves in relation to an adjacentsegment referred pain: Pain that is felt at a location distant from its source relative refractory period: Time after an action potential during which another action potential can occur only in responseto a suprathreshold stimulus resistance: Iorce opposingmotion; may refer to the force of water againsta patient or the force oppos-ing the flow of electricalcurrent rheobase: The minimum currentamplituderequired to excite a particular type of nerue fiber when a pulse with an infinitely long duration is aoolied shortwave diathermy: Electromagnetic radiation .-;rh

,

F"n'rpnr-

^t

1O7 tn

108 nrlec

npr

second spasm:An involuntarymusclecontraction spasticity: A type of musclehypertonicity in which resistance to passive thereis a velociry-dependent stretch of a muscle; the muscle resists quicker stretchesmore than slowerstretches specificheat: The amountof energyrequiredto raise the temperatureof a givenweight of materialby a givennumber of degrees stratum comeum: The superficialcornified layer of the skin that actsasa protectivebarier strength-duration (S-D) curve: Illustration of the relationship between the current amplitude and pulse duration required to produce a threshold stimulus to createan action potential in different rypes of nerve fibers and directly in denervated skeletalmusclefibers

substance P: A peptide that is thought to be an important neurotransmitterfor the transmissionof painful stimuli substantia gelatinosa: Lamina II of the gray matter of the spinalcord where afferentpain-transmitting fiberssynapsewith interneurons tendinitis: Inflammationof tendc.rns tetany: Steady conffaction of a muscle without witching thermal agent: A physicalagent*rat canincreaseor decreasetissuetemperature thermal conductivity: Rate at which a material can conductthermalenergy thermotherapy: The therapeuticuseof heat thrombophlebitis: A condition in which inflammation of the vein wall precedesthe formation of a thrombus thrombosis: The formatiory development,or presenceof a thrombus thrombus: A clot in a vesselor in one of the cavities of the heart traction: The applicationof a mechanicalforceto the body in a way that separates,or attemptsto separate, the joint surfacesand elongatethe sutrounding soft tissues transducerr A devicethat convertsenergyfrom one form to another ultrasound: Soundwith a ftequencyof greater*ran 20,000cyclesper second ultraviolet radiationr Electromasneticradiation with a trequenryof 7.5x 10rato 10r)cyclespersecond urticaria: Vascular skin reaction marked by the transientappearanceof smooth, slighdy elevated patches that are redder or paler than the surrounding skin and are often attended by severe itching vasoconstriction: Diminution of the crosssectionof vessels,generallyof the arterioles vasodilation: Dilation of vessels,generally of the arterioles venous stasis ulcer: An area of tissue breakdown and necrosisthat occursas the result of impaired venouscirculation viscoelastic: Having both viscous and elastic propeftles viscosity: The physicalproperty of resistingthe force tendingto causea substanceto flow, causedby frictionbewveenthe moleculesofa substance

Glossaryof CommonlyUseilTenrs

wavef,ofln: The shapeor visual representationof the changein energy intensity oveitime

-

wavelength: The distance between two successlve points in a wave that are in the same phase of oscillation

and Commonly[JsedAbbreviations Acronvms /

AC: Alternatingcurrent AOTA: AmericanOccupationalTherapyAssociation APTA: AmericanPhysicalTherapyAssociation AIP: Adenosinetriphosphate BNR: Beamnonuniformity ratio CHF: Congestiveheartfailure CNS: Centralnervoussystem CSF: Cerebrospinalfluid CT: Computedtornography CVA: Cardiovascularaccident(stroke) DC: Direct cuffent DOMS: Delayedonsetmusclesoreness DVT: Deepvenousthrombosis EMG: Electromyography ERA: Effectiveradiatingarea ES: Electricalstimulation Commission FCC: Federal Communicacions FDA: Foodand DrugAdminisrration FES: Iunctional electricalstimulation HP: Hot pack HVPC: High-volt pulsedcurrent ICIDH: Intemational ClassificationoI Impairments, Disabilities,andHandicaps IP: Icepack IR: Infrared

460

L: Left MEDr Minimal erythemaldose(for W treatment) MRI: Magneticresonanceimaging MVIC: Maximum voluntary isometricconffaction MWD: Microwave diathermy NDT: Neurodevelopmentaitraining NMES: Neuromuscularelectricalstimulation PCr Pulsatilecuffent field PEMF: Pulsedelectromagnetic PNF: Proprioceptiveneuromuscularfacilitation PSWD: Pulsedshorwvavediathermy with ultravioletA PWA: Psoralens R: tught elevation RICE: Rest,ice.compression, ROM: Rangeof motion SNS: Sympatheticnervoussystem SWD: Shotwave diathermy TENS: Transcutaneous electricalnervestimulation US: Ultrasound UV: Ultraviolet WHo: World Health Organization ': Minutes ": Seconds #: pounds

Units Unit (abbreviation): Measureof

Pulses per second (pps): Irequency when the errpnt