The role of trigger points in muscle pain…
Trigger points are felt as small, tender nodules and painful bands in skeletal muscles. These knots are hyperirritable spots. When muscles work in an eccentric fashion, that is a contraction occurs while the muscle lengthens, damage occurs within the muscle cells. The reason why these trigger points develop is because a neurotransmitter, Acetylcholine, is released in excess, which then causes a persistent, localized muscle contraction. This muscle contraction compresses blood capillaries which then reduces blood flow. Lower amounts of oxygen and glucose is then delivered to the muscle and an energy crisis is created. As a result, a number of pain sensitizing substances are released which activate nerve receptors that respond to pain. The muscle is unlikely to relax and thus, a vicious cycle is created.