Subacromial impingement syndrome (SIS) is actually a fairly common cause of shoulder pain and dysfunction. Symptoms occur when the shoulder is elevated, a position often used in golf and other sports activities.

Despite the many people affected by SIS the cause is still unclear. Doctors think the supraspinatus tendon of the rotator cuff gets pinched between the shoulder and the acromion when the arm is raised overhead. The acromion is part of the shoulder blade that curves around over the top of the shoulder joint.

What causes the impingement? It could be from changes in head, neck, and upper back posture. A forward head position pulls the shoulders forward in a slouched position. The shoulder blades move forward and up. Muscles get out of balance and soft tissues get pinched and irritated.