tendonitis in rotator cuff symptoms
The rotator cuff is a frequent source of pain in the shoulder. Anatomy. Your shoulder is made up of three bones: your upper arm bone (humerus), your shoulder blade (scapula), and your collarbone (clavicle). Your arm is kept in your shoulder socket by your rotator cuff. These muscles and tendons form a covering around the head of your upper arm bone and attach it to your shoulder blade. There is a lubricating sac called a bursa between the rotator cuff and the bone on top of your shoulder (acromion).