However, postural pain can be provoked by sustained loading at end-range. This pain can change rapidly as a result of different movements or positions. Typically, forces applied in one direction make the patient worse, while forces applied in the opposite direction may benefit the patient. Often this occurs with radicular symptoms and is accompanied by a trunk list. Once the list is reduced, the classic McKenzie patient has pain which peripherilizes with flexion and centralizes with extension.
Extension is thus the prescribed direction of therapeutic motion.
Dysfunction patients have pain which appears at end-range loading of a shortened structure. This is thought to be from adaptive shortening either in a muscle or joint capsule. Unlike derangement patients once the end point is released there is immediate relief. Clinically, the patient has decreased range of motion and pain at end-range. The McKenzie system prescription for dysfunction is to stretch the tissues in the painful direction for a few weeks.