Myofascial pain has been described as a dull, aching or burning muscle pain, soreness or numbness frequently characterized by a sensation of referred pain. Referred pain is a pain stimulus originating in one part of the body being felt in another muscle or muscle group.
Myofascial trigger points weaken the muscle in which they are present. The muscle experiences a constant state of contraction as the active trigger point tenses the muscle fiber, creating a taut band of muscle tissue. This taut band can become hard and rope-like and feels painful or stiff for the individual experiencing it. The affected muscles may have restricted motion and become quickly fatigued.
The pain associated with myofascial pain differs from other painful conditions, such as fibromyalgia, primarily in the way that it is experienced in a localized muscle or region of the body. However, myofascial symptoms may spread to other areas. An active trigger point or series of trigger points may cause adjacent muscles to become overworked, promoting the creation of new trigger points.
The sign of a myofascial trigger point is a focused point of tenderness or pain felt when pressure is applied. Pressure to a trigger point made with a finger may also cause a sensation of shooting pain along nearby muscles, such as from the back to the neck or shoulders. The trigger point feels like a hard knot of tissue to the touch, however it may not be apparent to the untrained observer because trigger points can be present deep within a muscle. A physical examination by a doctor is often required to uncover all present myofascial trigger points.