In this case, use a PNF pattern to eccentrically contract the antagonists of the subscapularis, which results in the facilitation of the external rotators and the reciprocal inhibition of the hypertonic subscapularis. A dysfunctional subscapularis muscle is often one problem amidst a chain reaction. Lewit and Kolar have published the most recent papers that describe chain reactions within the locomotor system. 11,12,17 Chain Reactions Chain reactions occur within groups of muscles that functionally work together to perform specific locomotor tasks, such as prehension, gait, maintenance of body statics and respiration. We will briefly examine the prehensile movement as it involves the subscapularis.
Prehension involves grasping for an object that is in front of the body.
Prehension occurs during eating, i.e., we reach out for food and bring it back to our mouth. The first component of prehension is the reaching out phase to grasp an object. This phase utilizes predominantly the flexor group of the hand and forearm to grasp the object. Then the upper extremity flexors and internal rotators of the humerus, i.e., subscapularis, are engaged to bring the object toward the body. Simultaneously, we engage our deep neck flexors, scalenes and SCM to flex our head forward to examine the object.