Trigger points are the hallmark of myofascial pain syndrome. If you find muscles with tight knots that feel like a tautly pulled band, you may have found a trigger point. But there are several different types of trigger points.
A central trigger point occurs when the muscle fibers at this location become impaired. As a result of the trigger point increased tension develops in the muscle fiber, and the fiber itself becomes a taut, tense band with easily irritated knots, or trigger points, along its length. The muscle has lost its ability to relax, and this can result in pain.
Source:
Simons, D., MD, Travell, J. MD, Simons, L., PT. Myofascial Pain and Dysfunction: The Trigger Point Manual. Vol. 1 Upper Half of the Body. 2nd Edition. Williams & Wilkins A Waverly Company 1999. Baltimore.
