MYOFASCIAL PAIN: A REVIEW

Shelley Pullen* ______ta ble hi: as so c iate d s y m p to m s

FEATURE FIBROMYALGIA MYOFASCIAL ABSTRACT A literature review on myofascial pain, concepts of fibrositis and MUSCLE SPASM Usually none Present with shortening fibromyalgia are presented. Myofascial pain is discussed as regards its definition, occurrence, behaviour, characteristics and modern MUSCLE WEAKNESS Uncommon Common approaches to treatment. Theories of the pathology of trigger points RANGE OF MOTION Not usually restricted Always restricted are described. Also the myofascial pain-dysfunction syndrome and MUSCLE ACTIVITY Painful diffusely Painful in local areas its clinical recognition are addressed. NODULES/CORD Diffuse tenderness Tend to cluster acute pain LOCAL TWITCH ON None Frequent PART TWO: TRIGGER POINTS PALPATION An historical overview of the literature relating to muscular pain WEATHER SINSITIVE Often Common was presented previously1. SKIN ROLL Usually Occasionally In recent studies it has been shown that myofascial pain syn­ TENDERNESS dromes are the most common causes of pain that bring patients to RAYNAUD’S Not present In acute cases PHENOMENON vasodilatation in chronic pain treatment centres. Among 283 consecutive admissions trigger areas, to a comprehensive pain centre, 85% were diagnosed independently vasoconstriction on referred zone by a neurosurgeon and physiatrist as being sufferers of myofascial syndrome. Fibrositis/Fibromyalgia and myofascial pain are not often clearly DIFFERENTIAL DIAGNOSIS OF MYOFASCIAL defined in the literature, but are now acknowledged as two very PAIN different entities. The aetiology of fibromyalgia comprises internal and environ­ Normal muscles do not contain myofascial trigger points; they mental factors while myofascial pain is associated with chronic or have no taut bands of muscle fibres; they exhibit no local twitch abnormal strains, infections, allergies, nutritional or metabolic fac­ responses and they do not refer pain in response to applied pressure. tors and emotional stress. Rogers and Rogers2, Simons3 and Sheon4 Escobar and Ballesteross tabulated a differential diagnosis in compared various aspects of fibrositis/fibromyalgia and myofascial myofascial pain syndrome (1987). They included myopathies, arth- pain. These are summarised in Tables I-III. ritides, musculoskeletal injuries (eg. tendinitis, bursitis overuse syn­ drome), neurological conditions (eg. neuralgias, radiculopathies), TABLE I: COMPARISON OF THE DEMOGRAPHY visceral conditions(eg. ischemic heart disease, peptic ulcer), viral or bacterial infections, neoplasm and psychogenic pain or behaviour. ) . FEATURE FIBROMYALGIA/ MYOFASCIAL

3 The diagnosis of myofascial pain is purely clinical. Histologic FIBROSITIS PAIN 1 studies show that there appears to be no evidence for inflammation, 0 2

but that something is wrong with the muscle6. The limited EMG d e studies available suggest an abnormality localised to the trigger point t SEX Mainly females Both sexes a and its associated taut band. This may reflect some kind of reflex d PERVALENCE fourth most common rheumatic Very common (

hyperirritability, mediated perhaps at a spinal level6.

r disorder e

h AGE Mainly 4 0 -6 0 years Any age s CHARACTERISTICS AND BEHAVIOUR OF i l b MYOFASCIAL TRIGGER POINTS u TABLE II: CHARACTERISTICS OF PAIN P An active trigger point causes pain, while a latent trigger point is e h

t clinically silent with respect to pain, but may cause restriction of

y FEATURE FIBROMYALGIA MYOFASCIAL movement and weakness of the affected muscle. This predisposes to b acute attacks of pain. Only active trigger points cause pain, but both d e t ONSET Gradual Acute/Gradual active and latent trigger points may cause dysfunction. n Normal stresses and strains produce slight tissue damage that a LOCATION Three or more Usually one r usually heals. However, if healing does not occur, areas of hyperex­ g

PAIN TYPE Diffuse, deep ache Sharp, localised e citability or structural change in muscle may form. These are called c RADIATION Widespread, Chronic Muscle-specific patterns n latent trigger points, and the individual may be unaware of their e TENDERNESS Multiple tender Over Trigger points - c

i existence. Precipitating factors may activate latent trigger point, thus

l points (7 - 12) one or more

r producing an active trigger point which may in turn be perpetuated e

d by specific factors. n Concurrent pathology such as nerve root compression and vis­ u The treatment for fibrositis is non-specific and is seldom cured,

y and use must be made of comprehensive and supportive team ceral and joint diseases may also cause activation or perpetuation of a trigger points. Afferent discharge from a compressed nerve root or w therapy. Myofascial pain on the other hand responds well to specific e diseased joint may cause facilitation of a spinal segment, thus acti­ t local therapy and is usually cured. a vating a latent trigger point within the same segmental distribution. G t e n * BSc (Physiotherapy), MSc student Physiotherapy Department, University o f the Witwatersrand i b Ithuseng Rehabilitation Centre, Ernest Oppenheimer Hospital, Welkom a S y b d e c u Physiotherapy, August 1992 Vol 48 no 3 Page 37 d o r p e R Non-pain symptoms of myofascial trigger points include excessive are used and normal saline has also been used to good effect. It has lacrimation, nasal secretion, pilomotor activity, changes in sweat been said that it is just the needle stimulus itself which has the effect patterns, electrical skin resistance, vasodilation with dermographia, and dry needling has become a favourable technique among clini­ skin temperature changes and reflex vasoconstriction (coldness lo­ cians. In most cases a series of two to five injections is sufficient. cally). Less frequently one may observe hypoaesthesia and local or Stretch and spray is another technique whereby a trigger point general fatigue or fine tremor weakness. Other non-pain symptoms may be deactivated. Vapocoolant sprays, usually ethyl chloride or may include postural dizziness, spatial disorientation and disturbed alcohol sprays, are used. The muscle must be stretched to the end weight perception. Most of these above-mentioned symptoms are point within the limits of pain. The spray is applied from origin to specific to myofascial trigger points in specific individual muscles. insertion of the muscle in parallel sweeping strokes, three or four times. At the end of each sweep the muscle is passively stretched to PATHOPHYSIOLOGY OF MYOFASCIAL its maximum within the limits of pain, until full range is achieved. TRIGGER POINTS Another technique combines injection with spray. This is valuable when a myofascial trigger point remains unresponsive to stretch and The pathophysiology of myofascial trigger points is poorly under­ spray. The muscle is injected as has been described and is immedi­ stood: Histologic examinations “have revealed areas of fibre de­ ately passively stretched using the stretch and spray technique. generation, proliferation of nuclei, and fatty infiltration. Mast cell Myotherapy is sustained pressure to the myofascial trigger point degranulation and platelet aggregation have also been seen. De­ with sufficient force and for long enough to deactivate the trigger creases in the level of ATP, ADP and AMP have been noted”7. point. This is a valuable technique for muscles which do not respond A generally accepted theory coupling the ideas of Simons, Mel- to stretch and spray, and is in fact useful for any trigger point in any zack and Simons and Travell is summarised as follows:8. muscle. Trauma disturbs the normal or weakened muscle through muscle Less commonly the techniques of stripping massage and ice injury or sustained muscle contraction. These traumas release free massage are used. The former is specific stroking of the muscle, calcium within the muscle through disruption of the sarcoplasmic deeper and slowly deeper, until the trigger point is felt and then reticulum and, with ATP, stimulate actin and myosin interaction and deactivated. The latter technique involves intermittent use of ice local contractile and metabolic activity which results in increases in instead of using vapocoolant spray. It is applied using the same noxious by-products. Substances such as serotonin, histamine, ki- principles of stretch and spray, but the effects on muscle spasm by nins, and prostaglandins sensitise and fire Groups 3 and 4 muscle excessive use of ice should always be considered. nociceptors, and a reverberatory neural circuit is established be­ Any of the above-mentioned techniques can be used to deactivate tween the nociceptors, the CNS, and the motor units. These afferent a trigger point. Treatment should always be followed by moist heat inputs converge with other visceral and somatic inputs onto cells in (even a hot bath or shower if possible), specific stretching exercises the dorsal horn, which project to higher centres and result in percep­ of the affected muscles and rest. If there is.no lasting improvement tion of local and referred pain. These inputs may be facilitated or then there are perpetuating factors which have not been addressed. inhibited by multiple peripherally or centrally initiated alterations in The consideration of perpetuating factors may include corrective neural input, including those produced by treatment modalities action of mechanical stresses, drug control of depression, inflamma­ (cold, heat, analgesic medication, massage, trigger point injections, tion or pain, management of nutritional inadequacies or metabolic TENS.). The cycle may be perpetuated by protective splinting of the disturbancesand the recognition of influencing psychological factors. ) . painful muscle through distorted muscle posture and by avoiding 3

1 painful stretching of the muscles. Any other perpetuating factors will

0 MYOFASCIAL PAIN DYSFUNCTION 2

support the reverberatory circuit.

d SYNDROME

e With sustained contractile activity local blood flow decreases with t

a resulting low oxygen tension, depleted ATP reserves and diminished There is much dental literature on the role of the skeletal muscles d

( calcium pump. Free calcium continues to interact with ATP to in the myofascial pain-dysfunction syndrome (MPD syndrome) and r

e trigger contractile activity, especially if actin and myosin are overlap­ in the temporomandibular joint (TMJ) pain-dysfunction syndrome. h

s ping within the shortened muscle, and a self-perpetuating cycle is Travell and Simons4 include the following concepts: i l established. Sustained increases in noxious by-products of oxidative The terms MPD syndrome and TMJ dysfunction syndrome over­ b u metabolism then contribute to the onset of the organic musculodys- lap widely and clinically it is difficult to make a sharp distinction. P trophic stage, with sensitisation of nociceptors within the interstitial When the symptoms include pain anywhere throughout the head, e h connective tissue at the trigger point and further disruption of the neck and jaw, the term craniomandibular syndrome is more appro­ t

y calcium pump. Muscle length has to be restored to prevent further priate. b perpetuation of the problem. If the process continues, the muscle d e bank initially tries to respond with hypertrophy but later breaks down The classical definition of the MPD syndrome is as t n to granular ground substance, eventually resulting in localised fibro- follows: a r sitis. g • Diagnosis requires the presence of one of the following: e

c * A unilateral pain in the ear or periauricular area; n TREATMENT OF MYOFASCIAL PAIN

e * masticatory muscle tenderness; c i l Palpation is required in order to confirm which muscles are * clicking or popping noises in the TMJ accompanies by pain

r or tenderness; and e responsible for the myofascial pain. The muscle must be put on a d stretch until the fibres of the “taut band” are under tension. The * limited opening of the jaw or deviation of the mandible on n

u opening.

stretch should be on the verge of causing local discomfort only and y • In addition there should be no clinical or radiological evidence of

a not the referred pain. Then one should palpate the area feeling for w ropey, indurated, tight areas, i.e. the taut band. Localise the spot of organic changes in the TMJ. e t maximum tenderness - this is the trigger point. a Three major viewpoints regarding the etiology of

G The aim of treatment is to deactivate the trigger point, to increase

t MPD syndrome: e range of movement, to eliminate perpetuating factors and to restore n i maximum function. The myofascial trigger point may be treated in • muscular origin; b a the following ways: • complex psychophysiological phenomenon; and S Injection: This often provides dramatic relief. Local anaesthetics • disturbed occlusal mechanics. y b d e c u d Bladsy38 Fisioterapie, Augustus 1992, deel 48 no 3 o r p e R The pain is in fart often referred to the joint from myofascial may lead to prompt administration of appropriate treatment and trigger points in the lateral pterygoid, sometimes the medial ptery­ management by a multi-disciplinary team. In this way “most patients goid or the masseter muscles. These trigger points can be inactivated will experience significant decreases in their pain, allowing them to in order to relieve the pain and, if necessary, the perpetuating factors return to the workforce and resume a normal life”. must be eliminated to provide lasting relief. REFERENCES CONCLUSION 1. Pullen SI. Myofascial pain: A review. SA Journal o fPhysiotherapy 1992;48(2)23-25. 2. Rogers EJ, Rogers R. Orthopaedic Review 1989;18(11). Ashbum concluded that in the case of persistent pain one should 3. Simons DG. Fibrositis/Fibromyalgia: A Form of Myofascial Trigger Points? The realise that this pain is a separate process from the original problem. American Journal o f Medicine Sept 1986;81 suppl 3A. 4. Sheon RP. Regional myofascial pain and the fibrositis syndrome (fibromyalgia). First any correctable pathology must be ruled out then the pain itself Comprehensive Therapy 1986;12(9) :42-52. should be addressed . 5. Escobar PL, Ballesteros J. Myofascial Pain Syndrome. Orthopaedic Review Oct 1987;16(10). Likewise the possibility of acute pain being myofascial in origin 6. Campbell SM. Regional Myofascial pain Syndromes. Rheumatic Disease Clinics o f should not be overlooked because all too soon this easily becomes North America Feb 1989;15(1). chronic pain. It is this chronic pain which leads to disability, decreased 7. Ashbum MA, Fine PG. Persistent Pain Following Trauma. Military Medicine Feb 1989;154. productivity and dramatic effects on the patient’s life. So accurate 8. Friction JR. Myofascial Pain Syndrome. Neurologic Clinics May 1989;7(2). diagnosis and at least an awareness of the myofascial origins of pain WORLD CONFEDERATION FOR PHYSICAL THERAPY

health problems which elderly persons may have, and take into POSITION STATEMENT* account the likely slower response to intervention. • The identification of gaps in services in health and welfare pro­ PHYSICAL THERAPY FOR THE CARE OF grammes for elderly people which may be filled by the provision of ELDERLY PERSONS physical therapy. The World Confederation for Physical Therapy • The provision of funding for research and programme develop­ Accepting the United Nations’ Principle for Older Persons - Item ment into aspects of physical therapy relevant to the care of elderly 10 (New York 1991): “Older persons should have access to health people should receive due recognition. care to help them maintain or regain the optimum level of physical, • That physical therapists participate in the education and training mental and emotional well-being and to prevent or delay the onset programmes for primary health care workers, including families. of illness”; Recognising the rapid escalation in the number of elderly persons PHYSICAL THERAPISTS CHART A COURSE throughout the world; FOR OLDER PERSONS Appreciating that epidemiological data indicates that 20% or more of elderly persons experience mobility and functional problems Healthcare issues and needs of older persons worldwide were the

) topics of a collaborative meeting between an international group of . which may compromise their well being; 3 physical therapists and representatives of the International Institute 1 Mindful of the financial implications of disability to the elderly indi­ 0 of Aging (United Nations) - Malta. As a result of the meeting a pilot

2 vidual, the family and the community; and short course on physical therapy services for older persons is planned d Aware that many physical problems may be prevented, corrected or e t ameliorated by the timely intervention of physical therapists; for 1993. a

d The physical therapists present were; Doreen Bauer from the

( Urges member organisations to take action by vigorously encoura­

r ging legislative and regulatory bodies to incorporate the following Western Pacific region, Jo Beenhakker from Africa, Neva Greenwald e h principles into their national planning and programmes. from North America and Margrit List from Europe, along with rap­ s i l • There should be active involvement of physical therapists with porteur, Barbara Sutcliffe and Lois Dyer. Present from INIA were b the director, Dr Alfred Grech, Dr Julian Mamo, Dr Mario Garrett u appropriate knowledge and experience of the development of P services for elderly people in policy and planning at international, and Marika Wirth. e The final report and proposed curriculum will be issued by INIA, h national and local levels. t 117 St Pauls Street, Valetta, VLT07, Malta, available on request. y • Prompt and coordinated services provided by physical therapists b should be promoted as an alternative to high cost hospital or d PILOT TEST SHORT COURSE e institutional care. t n • The provision of physical therapy services in the home or in pro­ At the meeting priority was given to raising awareness of the a r grammes organised for elderly persons who usually reside at home, contribution of physical therapy to services for elderly people and g

e such as out-patient clinics, day hospitals, day care centres or respite ultimate aims are: c • To improve health care services for elderly people by developing n care programmes, should be promoted as an alternative to high e c cost hospital or institutional care. relevant physical therapy attitudes, skills and knowledge. i l • The establishment of physical therapy programmes for those who • To develop physical therapy skills to influence policy both locally r e do not have direct access to mainstream services, for example and nationally. d n elderly persons in rural areas. The pilot course will address these aims and the resulting curricu­ u • There should be recognition that functional assessment, especially lum will be available for further courses worldwide. y a in the home environment, is necessary to determine the needs of Criteria for selection to the pilot course, costs and funding details w e elderly persons, and that physical therapists are key personnel in will be available from INIA. t a the management of mobility and physical function problems. Applications from developing countries are especially encouraged. G • That health promotion programmes conducted by physical thera­ * As devised by the Working Party of Physical Therapists at the t e pists and aimed at enhancing physical function, especially in well meeting with the International Institute of Aging (United Nations) - n i Malta, in January 1992, as agreed by the WCPT Executive Committee b elderly persons, may contribute subsequently to the development a in February 1992, for ratification at the next WCPT General Meeting

S of optimal health and well-being of elderly persons,

y • Reimbursement systems should allow for the complex and multiple in Washington in June 1995. b d e c u d

o Physiotherapy. August 1992 Vol 48 no 3 Page 39 r p e R