They are associated with the autonomic nervotic system. An example of the latter is pain caused by appendicitis. Acute pain can come to an end and may not recur. Chronic pain is very different. It may or may not have an observable cause.
Trigger points are highly irritable spots in a muscle, and contribute critically to chronic pain.
Dr. Bronson Ong s work is to stop them from irritating the muscles in which they reside. It seems that trigger points are laid down inside a muscle, when the muscle is insulted - by way of road accidents, injuries during sports, occupational hazards, and disease. Trigger points may even arise in an infant during its passage through the birth canal. Trigger points can arise anywhere in the musculo-skeletal structure of a person. In fact trigger points are formed before a baby is born.