Shoulder Impingement is mechanical compression, which can cause wear of the rotator cuff tendons. The rotator cuff is comprised of four muscles connecting the shoulder blade to the upper part of the shoulder joint. These maintain the ball (humeral head) within the socket (glenoid) during shoulder elevation.
Normally, the ball glides under the acromion (outer tip of the shoulder blade). Compromise of this function may cause friction and wear. Common causes include weakening, degeneration due to aging, bone spurs, inflammation, and overuse injuries.
Patients may complain of pain in overhead activity and awakening in the night. Manipulation may reproduce the symptoms. X-rays may show bone spurs and narrowing of the subacromial space. MRI may rule out more serious diagnoses.
Temporarily eliminate activities like tennis, pitching or swimming. A non-steroidal anti-inflammatory medication may be recommended. Surgery involves debriding tissue that irritates the rotator cuff and is favorable in about 90% of the cases.
Exercise to restore normal flexibility and strength of the shoulder blade and rotator cuff muscles. Try exercises in these videos to strengthen the rotator cuff muscle and scapular muscles, and control the incidence of shoulder impingement.
Source: American Orthopaedic Society for Sports Medicine