Impingement Syndrome, more commonly referred to as “thrower’s shoulder,” is a multi-symptomatic condition due to the rotator cuff muscles compressing against the structures forming the upper portion of the shoulder. The region is referred to as the subacromial space and includes the acromio-clavicular joint, coraco-acromial ligament and the acromion (outer edge of the scapula or shoulder blade). This narrowing of the space that the rotator cuff muscle tendons pass through causes the muscles to become irritated and inflamed, resulting in pain, weakness and in severe cases, the loss of mobility. One crucial aspect of the rotator cuff muscles daily functions is to act as a depressor of the humeral head. This in turn contributes to keeping the humeral head and shoulder stable. The rotator cuff muscles also assist in actively raising the arm overhead (flexion and abduction) and turning the arm in and out (internal and external rotation). A mechanical dysfunction is said to occur when the rotator cuff does not properly perform its functions. As a result, the rotator cuff becomes pinched against the structures along the upper portion of the shoulder or coracoacromial arch. If left untreated, it can lead to chronic wearing, tendonitis and subsequent tearing of the rotator cuff tendons. In more advanced stages of the syndrome, bony spurs begin to form further limiting the size of the subacromial space.