Trigger points and tender points: one and the same? Does injection treatment help?

Trigger points are defined as areas of muscle that are painful to palpation and are characterized by the presence of taut bands and the generation of a referral pattern of pain. Tender points are areas of tenderness occurring in muscle, muscle-tendon junction, bursa, or fat pad. When tender points occur in a widespread manner, they are usually considered characteristic of fibromyalgia. Trigger points, which typically occur in a more restricted regional pattern, are indicative of myofascial pain syndrome. In some patients the two phenomena may coexists, and overlap syndromes can occur. Although experienced examiners can generally identify the same tender points, interrater reliability of trigger points has been low in most studies. There is continued controversy regarding the defining characteristics and homogeneity of myofascial pain because of the variability of the examination findings. In appropriately selected patients, it appears that myofascial trigger point injections can be helpful in decreasing pain and improving range of motion in conjunction with a comprehensive exercise and rehabilitation program.