The shoulder joint is the most mobile joint in the body. It allows us to swing a tennis racquet, and throw a baseball. In order for all this mobility to occur, this joint sacrifices stability and makes it prone to injury. The shoulder joint is made of three bones: The humerus (upper arm bone which forms the “ball”), the scapula (shoulder blade which contains the “socket”), and the clavicle (the collar bone). The humerus and the scapula come together to form a ball and socket joint. The ball is much larger than the socket and the socket is very shallow. This allows for increased mobility but compromises stability, causing the ligaments and capsule to become very weak. The shoulder relies on four muscles called the rotator cuff to provide a dynamic stability to the joint. These muscles are located on either side of the shoulder blade and taper down into a tendon where they attach to the upper arm.
The rotator cuff is sandwiched between two bones (the acromion and the humerus) like a sock between the heel and the edge of a shoe. The tendon will become inflamed and painful with continuous rubbing (tendonitis). Rotator cuff tendonitis is an inflammation of the these muscles together with an inflammation of the bursa. Bursitis should be considered a symptom of rotator cuff tendonitis, not a separate diagnosis. Tendonitis is caused by repetitive overhead activity such as throwing a ball, playing tennis, or washing windows. As the condition worsens, the tendon will fray like a sock and eventually tear (rotator cuff tear).
Shoulder impingement and rotator cuff tendonitis are primarily treated conservatively with Physical Therapy and antiinflammatories. Physical Therapy consits of therapeutic exercise, neuro muscular rededucation of the rotator cuff muscles, postural education, joint mobilization, soft tissue mobilization and antinflammatory modalities. If symptoms persist, surgery is required to decompress the subacromial space. This is often done with bone spur removal, bursaectomy, and sometimes rotator cuff repair.