Tender points and trigger points of Fibromyalgia
What are tender points and trigger points of Fibromyalgia, and how are they different?
In normal individuals (and in patients with FM), there exist specific regions on the surface anatomy that are more sensitive to applied pressure than other sites. These areas are primarily at musculotendinous junctions and not at tendon insertion sites into bone. FM is a disorder of generalized pain amplification, and thus these regions may be exceedingly tender and are referred to as tender points. Prior classification criteria for FM (1990) required the presence of at least 11 of 18 tender points existing diffusely (above and below the waist) for ≥3 months. The pain in FM is best described as widespread in location, and a growing appreciation of patients clinically diagnosed with FM but without classic tender points led to this exam feature being left out of the current diagnostic criteria. Clinicians may still choose to perform examination of classic tender points to elicit discomfort suggestive of abnormal pain processing. The amount of point pressure utilized to elicit tender points is 4 kg/cm 2 (enough pressure to blanch your distal thumbnail).
In contrast to FM, regional myofascial pain syndrome is a localized pain syndrome characterized by the presence of a trigger point. Upon palpation of the trigger point, severe local tenderness and radiation of pain into characteristic regions is elicited. Though the discomfort of the myofascial pain syndrome remains regional, it is usually more widespread than bursitis or tendinitis. Regional myofascial pain syndrome most commonly involves the unilateral lower back, neck, shoulder, or hip region.