Trigger Points, or: Myofascial Triggerpoints, are hyper irritable spots that are found in muscles or fascia (= connective tissue found throughout the body). These little nodules, sometimes called: "knots", can cause strain and pain which is not necessarily limited to the spot where this Trigger Point is found.
The size of a Trigger Point varies in line with the size, shape, and type of muscle in which it is found. But they are all tender to pressure.
Direct compression or muscle contraction can cause a so called "jump sign", which is the immediate response by the individual to the tenderness or pain as a result of the Trigger Point. It is an involuntary response which seems to be out of proportion to the applied amount of pressure. This is one of the signs that a Trigger Point is active. The local tenderness can respond in a pain pattern distant from the spot.
