Rehabilitation of an elbow, following injury, is not a well-studied subject. Clinically, there is not a general consensus on which recovery method is optimal for healing an unstable elbow. When dealing with medial collateral ligament deficiency, many authors have proposed several forearm positions that will yield proper healing of the unstable elbow. Some researchers believe that active mobilization of the elbow with the arm in a vertical position is a safe protocol for rehabilitation with the forearm oriented in a supine pronated position. It was also mentioned that the compressive forces due to the active mobilization of the arm will stabilize the MCL deficient elbow'. This study is unique in that the proposal is that supine overhead range of motion will stabilize the MCL deficient elbow because gravity will act as a compressive force keeping the MCL deficient elbow intact. In this study, the gravitational stabilizing factor will be demonstrated comparing both the supine overhead range of motion and the commonly used upright range of motion protocol. The hypothesis is that supine overhead range of motion provides stability to a collateral deficient elbow. Moreover, supine overhead range of motion is a superior way to rehabilitate an unstable elbow because the forces of gravity hold the elbow in concentric reduction rather than distracting the elbow joint when the forearm is rehabilitated in an upright manner. The overhead ROM provided more stability to the unstable elbow, more especially to the elbows with the AC still intact.