A Revised Definition of Manipulation

BACKGROUND In 1976, Sandoz published an important article entitled bSome physical mechanisms and effects of spinal adjustments.Q In this article, Sandoz published a figure which was meant to describe the nature of joint manipulation with respect to where, in the total arc of the motion of a joint, manipulation was proposed to take place. Sandoz’s figure is shown in Fig 1. The figure was particularly effective in identifying several phases of a joint’s total motion, starting with the active range, defined as the range capable of being voluntarily produced by a person with their own motor power. Sandoz postulated that a further movement could be produced passively, either by the person themselves or by an external agent (ie, therapist), where dpassiveT implied the imposition of externally applied force. The outer margins of the figure represent the anatomic limit of motion of a joint, beyond which injury would occur to any of the holding elements and, with severe enough force, to the bony elements themselves. Active and passive motions are clearly shown to be less than, that is, within, the anatomic limit. Sandoz postulated the presence of a bparaphysiological space,Q beyond the passive range, but less than the anatomic limit. It was bintoQ this space that he postulated that a manipulation occurred. This bspace Q was described by others as a bzone of end-play,Q the bbarrier,Q or bthe