Diagnosis of myofascial pain syndrome.

Myofascial pain is one of the most common causes of pain. The diagnosis of myofascial pain syndrome (MPS) is made by muscle palpation. The source of the pain in MPS is the myofascial trigger point, a very localized region of tender, contracted muscle that is readily identified by palpation. The trigger point has well-described electrophysiologic properties and is associated with a derangement of the local biochemical milieu of the muscle. A proper diagnosis of MPS includes evaluation of muscle as a cause of pain, and assessment of associated conditions that have an impact on MPS.