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Medical Pain Education | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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MANAGING
MUSCLE PAIN IN MEDICAL PRACTICE Associate Professor Dr Norman A.
Broadhurst Acute muscle damage which has been
brought about by trauma of some kind, such as one would
experience in varying sporting activities, is reasonably well
understood and treated. The standard treatment being rest,
ice, compression, elevation and then mobilising the particular
tight tissues until normality is maintained. Most healthy
patients whether athletic or not manage to overcome these
injuries and are restored to normal function with the minimal
amount of disruption to training programs or work output.
Unfortunately, some patients are either poorly treated or
poorly advised in respect to rehabilitation of the injured
part, thus re-injury occurs or the old injury never seems to
get better and goes on to a chronic status which may develop
myofascial problems as a consequent of the original
injury. Objective - Signs Subjective - Symptoms In the above description the
concept of the notorious twitch response has not been
mentioned. Although the localised twitch response is a very
noticeable phenomena of people with painful muscles, such an
entity is not always readily elicited, in fact it would appear
from the literature that there is no reliability that
irritating a trigger point will always produce a twitch
response. In a recent review of myofascial
pain, Kemp (Postgraduate Medicine 1994) stated "The challenge
of myofascial pain syndrome lies not only in the lack of
specific accepted diagnostic criteria, but also in the
difficulty of eliciting specific physical responses. How then,
does the primary care physician approach clinic evaluation and
treatment?" Kemp went on to say that "the diagnosis of
myofascial pain syndrome may become less challenging as
clinical criteria become better defined." Confusion exists as to the place of
myofascial pain in compensation cases because the entity
occurs in a wide variety of settings and the etiology is not
clearly defined. However, early diagnosis with aggressive
treatment invariably yields good prognosis but not
always.Treatment modalities for myofascial pain have been via
the use of: While trigger points have had many
challenges to their identity and entity, some studies have led
to the support of the existence of trigger points. The
so-called trigger point area with its well known essential
zones and spill-over zones have been subjected to EMG studies
and it has been found that sustained spontaneous EMG activity
can be found within one to two millimetres of the nidus of all
trigger points in the trapezius muscle but such a nidus is
absent in non trigger point areas. Hubbard and Berkoff
concluded that the trigger points were caused by
sympathetically activated interfusal contractions. Other
supporting evidence was thought to be forthcoming by the use
of dolorimetry and thermography. Unfortunately, there was no
evidence to correlate the pain producing areas on dolorimetry
with the patient’s pain. Likewise the thermography did not
correlate with the colour changes and the area of patient’s
pain. A major problem in regard to
identifying the presence of trigger points, is the fact that
taut bands have been found in patients with fibromyalgia,
myofascial pain and controls. The table below gives a summary
of the various criteria which can be used to identify some of
the more commonly recognised categories of muscle
pain. Table 3. Comparision of myofascial
pain syndrome, fibromyalgia and chronic pain
syndrome Myofascial pain
Fibromyalgia Chronic pain
Similarities Symptoms Muscle pain
present Muscle pain
present Muscle pain may/may not be
present Acute or chronic
Pain Chronic
pain Chronic
pain Signs Muscle tenderness on
palpation Muscle tenderness on
palpation Muscle tenderness on
palpation may/may not be present Differences Symptoms Local or regional pain
distribution Diffuse pain involving
several body regions Pain may be in any
distribution often with "shifting" focus over
time Acute
onset Insidious
onset Insidious onset, may follow
acute injury or illness Non musculoskeletal symptoms
occasionally occur Non-musculoskeletal
symptoms(eg, fatigue, sleep disturbance, irritable
bowel) usually present Non musculoskeletal symptoms
usually present Signs Trigger points with typical
zones of reference Tender points without
referred pain in 11 of 18 specific
sites Trigger points and /or tender
points may be present, but not necessary for
diagnosis Local twitch response present
at trigger points Local twitch response absent
at tender points Local twitch response present
only if myofascial syndrome also
present Disability Minimal temporary disability
with treatment Disability, often partial,
may/may not be present Usually complete disability
with severe
deconditioning Nice et al found poor intertester
reliability with regard to judgements of physiotherapists when
trying to establish the presence of trigger points in patients
with low back pain. This study indicated Kappa values of .29
and .38 for positive agreement and negative agreement
respectively. A major problem of the study by this was the
fact that all patients were examined side lying and the study
adopted a In another study Njoo and Van der
Does suggested that the clinical use for trigger points could
be increased when localised tenderness and the presence of
either a jump response or the patient’s recognition of his
pain used as criteria for the presence of trigger points. This
contrasts markedly with Simons criteria which was published in
1990 (see table 1). If the management of the patient’s
pain depends upon defining and treating the trigger point,
then obviously criteria for its establishment is important.
Following on from the Njoo and Van der Does study, it would
seem that localised tenderness and the recognition of the
patient’s complaint would be sufficient criteria to treat the
painful area whether the concept of a trigger point is
important or not. Treatment modalities which are open
to non medical trained people are the use of various muscle
stretching techniques. For those who are medically qualified,
injections into the most tender area, which may or may not
produce a twitch response, have varying response from one
study to another. Normal saline and varying kinds of local
anaesthetic with or without steroid have all been established
as being efficacious to some extent. What does appear to be
important in treating the patient is the patient’s perception
of their pain and the worth of the treatment. Following on
from psychological studies in relation to fibromyalgia, it
appears that patient’s who are more aware and informed of
their pain are able to be gainfully employed whereas those who
have poor self esteem and poor understanding of their pain
profile tend to finish up with disability pensions. It could
be that the variation in treatment modalities for this simple
entity may well reflect the psychological problems associated
with chronic pain.In summary, it could be said that patients
with chronic muscular pain in which a central area can be
identified can be successfully treated by massage, dry
needling or injection of selected substances, followed by
stretching and we don’t need to chase trigger points.Table 1.
Proposed diagnostic criteria for myofascial pain
syndrome A diagnosis of myofascial pain
syndrome can be made if 5 major criteria and at least 1 of 3
minor criteria are satisfied.Major
Criteria 1. Localised spontaneous pain2.
Spontaneous pain or altered sensations in expected referred
pain area for given trigger point3. Taut, palpable band in
accessible muscle4. Exquisite, localised tenderness in precise
point along taut band5. Some measurable degree of reduced
range of movementMinor Criteria 1. Reproduction of spontaneously
perceived pain and altered sensations by pressure on trigger
point2. Elicitation of a local twitch response of muscular
fibers by transverse "snapping" palpation or by | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||