(Above) Milton Trager:  Former Boxer, MD, and creator of the Trager approach.

This style of passive joint mobilization is based on the work of Dr. Milton Trager.  Trager realized from a young age that physical pain was often a result of unconscious, psychological defense structures holding the body in a state of structural dysfunction.  In order to have the body release these defenses, he developed a therapy where the body is gently rocked, swayed, and shook.  It's not unlike when a crying baby falls asleep in a car.  The body becomes so relaxed, that the holding patterns (and pain) seem to fade away.