Trigger point firing point (in Greek) is an irritable discrete point in muscles that occurs either with local pain in a specific part of the body or with reported pain, that is to say it reflexes elsewhere. As a result, the person feels intense pain and there is a restriction on movement
Trigger points are active and inactive. The first may cause pain even during rest and are particularly painful in their palpation. They are caused by a muscle injury, bad posture, or a wrong industrial body.
Inactive trigger points are older points which show symptoms after a while because they were not encountered when they occurred. Often an inactive point is reactivated due to excess muscle or excessive stretching. (Alvarez, Rockwell, 2002)