Br J Sp Med 1991; 25(4)

Physiotherapy Modalities

Introduction to manipulationK. A. I. Keir MCSP, Dip TP and G. C. Goats PhD, MCSPSchool of Physiotherapy, the Queen's College, Glasgow, UK

OriginsThe art of manipulation was known to Hippocratesand the physicians of ancient Rome, and has passeddown a long line of medical manipulators andbonesetters to present day practitioners; osteopaths,physiotherapists, chiropractors and manipulatingphysicians and surgeons. Osteopathy and chiroprac-tic, unlike physiotherapy, at present remain outsideorthodox medical practice in the UKThe subject has always been contentious, often

acrimonious, with much factional and interprofes-sional rivalry, but in the late 20th century the practiceof manipulation is finally achieving scientific respect-ability through the application of biomechanicalprinciples and recent advances in neurophysiology,together with a serious attempt to prove efficacythrough controlled randomized clinical trials. Thusosteopathy and chiropractic may yet be extended aguarded welcome into the orthodox medical fold.

This paper will describe briefly the terminologyused in manipulation and discuss patient assess-ment, indications for treatment and the commonmanipulative techniques. A review of presentknowledge of the physiological effects of manipu-lation will accompany a discussion of clinical out-comes based upon data from clinical research.Osteopathy and chiropractic were both founded in

the USA during the late 19th century. Andrew Still,the father of osteopathy, based his treatment on thebelief that all symptoms arose from abnormalities ofsegmental motion, whilst David Palmer, the founderof chiropractic, was convinced that symptoms ofdisease in other body systems developed fromchanges in vertebral alignment1.Within orthodox medicine, physiotherapy is ack-

nowledged to play an important role in the manage-ment of musculoskeletal problems. Central to prac-tice is the use of manual skills, including massage andpassive joint manipulation. Physiotherapists maywork either independently or in conjunction withtheir medical manipulator colleagues, whose workextends to manipulation under anaesthesia. Thisprocedure will not be covered here.

Techniques have developed along similar lines ineach of the professions, regardless of the philosophygoverning their use, with only minor differences ofinterpretation.

TerminologyAny discussion amongst manipulators is hamperedby a vocabulary that means different things todifferent people, the gulf never greater than betweenthe general public and the medically qualified.Perhaps the most accurate description of manipu-lation is given by the Oxford Dictionary: 'to work withthe hands, to handle or manage'. Many lay peopleerroneously believe that the term implies the use offast jerking techniques, and carries with it the stigmaof 'quackery' or connotations of 'putting bones back'by the use of large amounts of ill-advised force andsmall amounts of brain power.Those who employ manual techniques as the tools

of their trade use the term manipulation to encom-pass a wide variety of procedures from the mostgentle to very vigorous, including both low- andhigh-velocity applications (Figure 1). The wealth oftechniques available is described fully and illustratedelsewhere2-7.Manipulative therapy procedures are applied pas-

sively to the patient who does not actively participateapart from giving consent. These may be usefullysubdivided into (1) soft tissue techniques, (2)mobilization techniques applied to joints, and (3)manipulation or high-velocity thrust techniques alsoapplied to joints.

VigorousforceA

Geniforc

Address for correspondence: Mrs K Keir, School ofPhysiotherapy, Faculty of Health Studies, The Queen's College,Crawfurd Building Southbrae Campus, Southbrae Drive,Jordanhill, Glasgow G13 1PP, UK© 1991 Butterworth-Heinemann Ltd0306-3674/91/040221-06

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A rapid singlemanipulation

/HVT\

Passive Slow repetitivemobilization oscillatory movements

Soft tissue technique Generalized,,F massage, stretching preliminary

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Frequentlyused

Figure 1. The types of manipulative therapy rankedaccording to force applied and frequency of use. HVT,high-velocity thrust

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Soft tissue techniquesTraditional massage falls into this category and isapplied to muscles, fascia and ligaments. Thesetechniques are dealt with thoroughly elsewhere8-10,and this paper will only discuss the manipulation ofjoints.

MobilizationsThese techniques are amongst the most commonused in the treatment of musculoskeletal problemsand are either repetitive oscillatory movements, orsustained stretches at the end of range. Suchprocedures remain under the patient's control.Mobilizations can be divided into localized 'specific'procedures, and more generalized techniques.

Figure 2. Pressure applied through a spinous process inthe lumbar spine in a posteroanterior direction

Figure 3. Translatory movement of the talocalcaneal joint

-a

Figure 4. Translatory movement of the glenohumeral joint

As the name suggests, specific techniques actdirectly on the joint involved, with the operator usinganatomical structures as levers. Spinous and trans-verse processes of the vertebral column are fre-quently employed as short levers (Figure 2) toproduce translatory gliding and rotation of neigh-bouring articular surfaces in the accessory range of

1112movement" .

In a peripheral joint, the proximal bone of thearticulation needs to be carefully fixed so that itsdistal partner may be moved, e.g. in the talocalcanealjoint the talus is fixed so that the effects of atranslatory glide of the calcaneum are localized(Figure 3), and the scapula is fixed by the patient'sweight to allow translatory gliding of the humeralhead in the glenoid fossa (Figure 4).

Non-specific generalized techniques, such as rota-tion of the lumbar spine, use longer levers offered bythe shoulder, pelvic girdle or limbs, and producetheir effects over several joints. The force required inthese situations is proportionately reduced by thegreater leverage'3.

Manipulation or thrust techniquesA manipulation consists of a single high-velocitythrust applied to a joint, or series of joints andassociated soft tissues. The aim is usually to restorelost movement and to relieve pain. These techniquesare only performed on a relaxed patient. A manipula-tive thrust technique momentarily takes the jointfurther than its normal physiological range. Accuratelocalization of the joint position before the technique,followed by a skillfully applied thrust, will result in amovement which is so fast that it is complete almostbefore the patient knows it has begun"4.

This procedure is sometimes indicated when a jointfails to achieve full mobility after mobilization.Although used mainly in the treatment of spinalproblems, manipulation can be employed to treat theshoulder or sacroiliac joints, and the small joints of

14the hand and foot' .

Examination and assessmentEvery manipulator, regardless of his professionalorigin, must identify accurately the site of the lesionbefore treatment. Manipulative therapy aims to beeffective and efficient, but above all safe. The goodpractitioner will meticulously examine the patient toexclude contraindications (Table 1) and identify thestructure causing the problem, be it a joint, ligamentor muscle3'6'15The contribution of James Cyriax to the analysis of

musculoskeletal problems is invaluable. Most man-ipulators examine patients using methods developedby him, although upon this foundation manyrefinements have been added"6 '5. The distributionof symptoms and behaviour of pain at rest andduring activity through a 24-h period are noted,together with a detailed account of the onset.

This information is interpreted by the therapist andfurther tests conducted until the faulty structure islocated. In particular, discrepancies between active

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Table 1. Contraindications to manipulative therapy

Mobilizations (oscillatory techniques)MalignancyBone disease, e.g. Paget's disease or osteomyelitisActive inflammatory and infective arthritis, especially

rheumatoid arthritis of cervical spineSigns of spinal cord pressure or cauda equina lesionsInvolvement of more than one spinal nerve root on one side, ortwo adjacent roots supplying one lower limb

Manipulation (high velocity thrust techniques)As for mobilizations plus:

Spinal deformity, either congenital or longstandingCervical or thoracic pathology producing neurologicalsymptoms in lower limbs

Undiagnosed painSevere nerve root painGeneralized hypermobilitySevere degenerative changes in the affected jointVascular abnormalities, e.g. vertebral artery involvementMost craniovertebral and some lumbosacral anatomicalanomalies

Advanced diabetes where tissue vitality is low

and passive movement are identified, measured andanalysed. The importance of this process cannot beunderstated as it forms the baseline for implementingand evaluating all subsequent manipulative proce-dures.

IndicationsManipulative therapy is indicated by pain anddysfunction of musculoskeletal origin, either oflongstanding or of recent onset, occurring in verte-bral and peripheral joints. Manipulation is not thepanacea for every complaint of mechanical origin, butskilfully employed at the correct stage, it can yieldconsiderable benefit3'66 1.Most joint problems can be placed into two

categories, those which will respond quickly totreatment, e.g. an acute wry neck, and those whosepathology or injury generally respond slowly, e.g.whiplash injury. The so-called 'mirade cures' fre-quently extolled by sufferers are often problemsreadily amenable to manipulative procedures. Oftenthe manipulator will recognize that prompt assess-ment and an accurately localized intervention willhasten the healing that would eventually occurnaturally. Occasionally unscrupulous operators willexploit this to preserve the mystique of manipulation.

ContraindicationsThe manipulator who has full knowledge of thepatient's medical status knows dearly those situ-ations in which thrust techniques are absolutelycontraindicated and those where mobilizations areunwise14.

Diseases and injuries of the bone and jointscompletely contraindicate thrust techniques. Gentlemobilization and soft tissue procedures can be usedsafely in situations where thrust techniques couldnot, such as severe nerve root entrapment syndromes(Table 1).

Physiological effectsThe effects of manipulation upon physiologicalmechanisms remain inadequately investigated experi-mentally. Some data exist and the important contri-butions are reviewed briefly below.

Relief of painThe pain-gate theory and recent advances in articularneurology offer a possible physiological explanationfor the analgesic effects of manipulation in thetreatment of pain and muscle spasm'6' 17. Largediameter afferent fibres embedded in the jointcapsule and associated ligaments'6 are stimulated bythe tension produced by manipulation. This activityinhibits the small diameter nociceptor afferent inputto the ascending pathways in the spinal cord, thusreducing the experience of pain at a cortical level'8.Reflex protective muscle spasm, frequently a result ofpain, will clearly reduce as pain subsides'4, thusreducing discomfort further.However, Zusman'9 challenges Wyke, reporting

electrophysiological studies on cats and primates thatshow insufficient numbers of large diameter jointafferents are stimulated by oscillatory passive move-ments to reduce joint pain by pain-gating. Hencepassive movements performed on an inflamed jointare likely to stimulate rather than inhibit nociceptoractivity. These findings lead to the conclusion thatthe analgesic effect of passive joint movement ismediated by the endogenous opiate neurotransmit-ters active in the descending pain suppressionmechanism20'2'A further alternative view is offered2' that an

effective, albeit temporary, decrease in the perceptionof pain occurs by inhibition of reflex musclecontraction through the stimulation of joint afferentsby an end of range passive movement.

Increased joint rangeWhere resistance to movement is due to tissuetension rather than pain, such as the contracture of acapsule or ligament after immobilization, treatment isaimed at elongating these structures to restore jointmobility.The force required to stretch a ligament from zero

tension to failure, and the deformation which results,can be depicted on a stress-strain curve (Figure 5).This shows that the ligament exhibits first elastic andthen plastic behaviour before failure, and that thisrepresents different stages of collagen deformation.The 'toe' phase and 'linear' phase lie within theelastic region, and elongation of a normal ligamentunder these conditions is completely reversible.

In the toe phase, single collagen fibres at rest areusually corrugated. The sinuous shape adopted isreferred to as 'crimp'. When stress is applied to acollagen fibre, the initial effect is to straighten thecrimp and 'take up the slack' (Figure 5). During the'linear phase', under a continued slow sustainedstretch, the normally oblique lattice work of collagenfibres realign themselves in the direction of the forceapplied. Proteoglycans (large protein molecules) and

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water are displaced and bonds within individualcollagen fibres become strained.

If further stretch is applied, the structure displays acharacteristic 'plasticity' (Figure 5) at the point where

ic' - Elastic region Plastic region

8 Toe phase Linear phase

E 7 _

_ / ~ ~ ~~~~~~I

en 4 / A=Yield Point

3 B=Maximum Stress

2 *=Failure1 : I | I I " ' '

3 6 9% Strain

some irreversible lengthening begins, and failure ofthe material becomes likely11 1. Thus, in a shortenedstructure, the application of a slow sustained force,such as a mobilization technique used at the end ofrange, should be applied to stress the ligament andcapsule into the beginning of 'plastic' range. This willcause a degree of permanent tissue lengtheningwithout inducing failure of the structure'2.Manipulative techniques not only help regain

movement, but also normalize the stresses uponmuscles, collagenous tissues, blood and lymphaticvessels, thus improving their function'& 15. Control-led passive movement of joints has also been shownto increase the rate of tendon repair and decreasefriction between a tendon and its sheath during therepair process23.

12 15 Psychological effects% .-

Physiological range Injury

= = Stages of deformation range of collagen

Figure 5. Normal stress-strain curve for a ligament

Undoubtedly the psychological effect of skilfulhandling and the feeling that the manipulator haslocated the spot exerts a powerful placebo influencethat contributes to the potency of manipulativeprocedures. This remains unquantified"4.

Table 2. Comparative trials of spinal manipulation

Authors Year Number Duration of Control Study treatment Resultsin trial symptoms treatment

Berquist-Ullman 1977 217 <3 months SWD 1. Back school 70% better in 2 months. Treated groupsand Larson34 2. Physiotherapy improved faster. Back school group had less

(including sickness absencemanipulation)

Coxhead et al.' 1981 334 Average 14 SWD and 1. Manipulation/ Manipulation group had significantly lessweeks back care talk mobilization pain. More treatment led to more

2. Exercises improvement3. Traction4. Corset

Evans et al.2 1978 32 >3 weeks Cross-over Analgesics and Significant results in group who haddesign manipulation manipulation first. Pain less, mobility

increased

Fisk29 1979 20 <35 days 10 normal Non-specific Significant improvement in SLR in back painsubjects manipulation subjects after manipulation

Glover et al.' 1974 84 +7 days Untuned Non-specific Manipulation group improved immediately,SWD manipulation otherwise results not significant

Hoehler eta/.31 1981 95 2-3 weeks Massage Rotational Manipulated patients had less painmanipulation

Mathews et al.32 1987 513 1-3 months 1. Local Sclerosant Non-significant result due to small numbersanaesthetic injection

2-4 months 2. Heat Manipulation 30% difference in recovery rate after 6 days3. Heat Traction Advantage at 6 days in treated group over

control group4. Local Epidural At 3 months, treated group had significantly

anaesthetic injection less painRasmussen33 1979 24 2 weeks SWD Manipulation 92% improved in 2 weeks

Sims-Williams 1978 94 Not stated Microwave Mobilization/ Treated group had less pain, felt treatmentetal.36 diathermy manipulation helped and could do lightworkSims-Williams 1979 94 Significantly Microwave Mobilization/ Results not significantet a/.24 longer than diathermy manipulation

1978 study

SLR, straight leg raise; SWD, shortwave diathermy

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Clinical resultsResearch seeking to evaluate the effectiveness ofmanipulative therapy to peripheral joints is scarce,with the majority of trials addressing the problem oflow back pain. Research into the effectiveness ofmanipulative therapy for low back pain has so farfailed to demonstrate a long-term benefit significantlybetter than for other forms of treatment, or indeed ofnature alone. There is little evidence that manipu-lation hel s those with severe or chronic backproblems , although a non-blind trial comparingchiropractic and hospital outpatient (physiotherapy)treatment, in which both groups used manipulation,concluded that chiropractic confers a long-termbenefit in severe and chronic pain when compared tohospital management25. However, the validity ofthese results has been questioned because of flaws inthe methodology26.Adequately randomized and controlled clinical

trials of spinal mobilization and manipulation haveshown a definite, short-term improvement in pain,movement and functional ability, whilst longer termeffects are less clear. Direct comparison between themany studies is complicated by the combination ofmanual therapy with other treatments27. Manipu-lation relieves pain and increases mobility morerapidly in those patients whose symptoms have ashort history (Table 2)28-33.A study of cervical manipulation showed that

frequency and intensity of migraine, and subsequentdisability, was improved with manipulative therapy.Manipulative thrust techniques were not significantlymore effective than mobilization alone, and manipu-lation or mobilization by chiropractors did notproduce results that were significantly better thanmobilization by physiotherapists37.Evidence exists supporting the use of passive

movement of immobilized tissue to prevent andresolve joint contractures, connective tissue atrophyand delayed healing38'39.

Several reasons have been identified for the failureto achieve significant results in clinical trials studyinglow back pain'4 4. The heterogeneity of the patientgroup, the subjective nature of pain assessments as ameasure of outcome, the interpersonal skills andtraining of the manipulator, and the impossibility ofrunning a double-blind trial are contributing factors.Single case study methodology may offer a validalternative for the evaluation of manipulative ther-apy4l.

ConclusionManipulative therapy encompasses clinical diagnosisand treatment of musculoskeletal pain and dysfunc-tion. A thorough initial analysis of the patient'sproblem, accurate therapeutic intervention, andevaluation of the subsequent effects is central to thesuccess of this treatment. The therapeutic benefits ofmanipulative treatment lie mainly with restoration oflost function and the relief of pain. Thus it has muchto offer in the management of soft tissue and jointinjuries sustained during sport. Clinical trials haveshown spinal manipulative therapy to give fast relief

of symptoms of short duration, whilst passivemovement in general has been shown to have abeneficial effect on immobilized tissue39.

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reference to the lumbar spine. In: Grieve G, ed. ModernManual Therapy of the Vertebral Column. Edinburgh: ChurchillLivingstone, 1986: 605-21.

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3 Cyriax J. Textbook of Orthopaedic Medicine, Vol. 2, 11th ed.London: Baillibre Tindall, 1984.

4 Hartman L. Classification and application of osteopathicmanual techniques. In: Glasgow EF, Twomey LT, Scull ER,Kleynhans AM, eds. Aspects of Manipulative Therapy, 2nd ed.Edinburgh: Churchill Livingstone, 1985.

5 Kaltenborn FM. Mobilisation of the Extremity Joints, 3rd ed.Oslo: Olaf Norlis Bokhandel, 1980.

6 Maitland GD. Vertebral Manipulation, 5th ed. London:Butterworth, 1986.

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11 Bogduk N, Twomey LT. Clinical Anatomy of the Spine.Edinburgh: Churchill Livingstone, 1987.

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13 Blackman J. Manipulation: a personal view. In: Grieve G, ed.Modern Manual Therapy of the Vertebral Column. Edinburgh:Churchill Livingstone, 1986: 656-60.

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34 Berquist-Ullman M, Larson U. Acute low back pain inindustry. Acta Ortho Scand 1977; 170(Suppl): 1-117.

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