4.0 DIAGNOSIS
4.1 HISTORY
As in most conditions, a detailed history is imperative for an accurate diagnosis. Below are a number of key questions that should be asked when attempting to diagnose MPS.1. How would you describe the pain?
As a general rule, the symptoms associated with MPS are poorly localised and present as a dull, throbbing or aching pain (Rachlin, 1994). Stiffness and fatigue is generally reported (Rachlin, 1994) and on rare occasions, symptoms may manifest as an excruciating or burning pain (Auleciems, 1995).
2. How did the pain begin?
The onset of pain tends to be abrupt, although the symptoms may worsen over time (Auleciems, 1995).
3. What relieves the pain?
Typically, short periods of rest, slow and passive stretching and short periods of light activity will aid in the reduction of symptomology . Patient's may obtain relief by taking a hot bath, the use of moist heat over the TrP, or a cold pack over the area of referred pain (Auleciems, 1995).
4. What exacerbates the pain?
Strenuous activity, contracting the affected muscle against a resistance, pressure on a TrP and cold, damp or drafty conditions may serve to augment the pain (Travell & Simons, 1983).
5. How have you been sleeping at night?
A disturbed sleep pattern is another diagnostic feature of MPS. The patient will often report difficulty in falling sleeping, restless sleep and waking in the morning with feelings of fatigue (Cantu & Grodin, 1992). These findings however, are more commonly associated with MPS presenting in the upper body.
4.2 PHYSICAL EXAMINATION
The examination of taut bands and trigger points is fraught with issues of inter and intra-tester reliability (Nice et al, 1992). Adequate training is advised to develop the skills necessary to make valid assessments of active TrPs (Simons, 1990), yet no evidence exists to support this belief (Riddle et al, 1993).Before beginning the assessment, the patient should be comfortable and warm. Individuals with MPS may also present with weakness of the affected musculature and a decreased range of motion at the joint/s which the muscle crosses (Rachlin, 1994). It is therefore prudent to assess muscle strength and joint range of motion, and compare the findings with the contralateral side.
4.3 PALPATION TECHNIQUES
When testing for taut bands and TrPs, 'flat palpation' is the most useful diagnostic technique for the majority of muscles in the leg and foot. Below is a description of flat palpation as reported in Travell and Simons (1983).
"... flat palpation refers to a moving fingertip that employs the mobility of the subcutaneous tissue to slide the patient's skin across the muscle fibres. This movement permits the detection of changes in the underlying structures. The skin is pushed to one side of the area to be palpated (Fig. A) and the finger slid across the fibres to be examined (Fig. B) allowing the skin to bunch on the other side (Fig. C). Any ropy structure (taut band) within the muscle is felt as it is rolled under the finger. A taut band feels like a cord 1-4 mm in diameter. Transverse snapping palpation of a taut band can be mentally compared to what plucking a violin string embedded in the muscle would feel like"."When a band is identified, it is explored along its length to locate the maximum tenderness in response to minimum pressure; that is the TrP".
Another technique described in Travell and Simons (1983) that is indicated when palpating the gastrocnemius or soleus muscles is the 'pincer palpation'.
Figure 2. Cross-sectional schematic drawing showing pincer palpation of a taut band (Travell & Simons, 1983).
"The technique of pincer palpation is performed by grasping the belly of the muscle between thumb and finger (Fig. A) and squeezing the fibres between them with a back and forth rolling motion to locate taut bands (Fig. B/C)"."When a band is identified, it is explored along its length to locate the spot of maximum tenderness in response to minimum pressure; that is the TrP".
4.4 PHYSICAL RESPONSES
Upon palpation of a TrP, a number of responses may be elicited.1. Local twitch response: a major diagnostic feature of a TrP in a taut band is the local twitch response and is defined as a localised twitch of a muscle (Travell & Simons, 1983).2. Jump sign: as its name suggests, this occurs when enough pressure is applied to an active TrP to make the patient jump. The amount of pressure required to elicit the jump sign provides an indication as to the irritability of the TrP (Travell & Simons, 1983).
3. Induction of referred pain: this is when the palpation of an active TrP induces a pattern of referred pain, and usually occurs following sustained and firm pressure. It is important to remember that in addition to localised pain, the pattern of referred pain may develop immediately, or take up to 10 sec to appear (Travell & Simons, 1983).
NOTE: Palpating TrPs can greatly exacerbate the symptoms of referred pain for a period of hours to days. As such, it is important to treat the affected area with specific myofascial therapy. As podiatrists generally have no formal training in this area, appropriate referral may be necessary.
