'Subacromial bursitis' is a condition caused by inflammation of the bursa that separates the superior surface of the supraspinatus muscle tendon (one of the four tendons of the rotator cuff) from the overlying coraco-acromial ligament, acromion, coracoid (the acromial arch) and from the deep surface of the deltoid muscle. The subacromial Synovial bursa helps the motion of the supraspinatus tendon of the rotator cuff in activities such as overhead work. Musculoskeletal complaints are one of the most common reasons for primary care office visits, and rotator cuff disorders are the most common source of shoulder pain.