(from WikiPedia)   Shoulder.  Posterior view at left. Anterior view at right.  1. Clavicle,   2. Scapula (with 3. Scapular spine, 4. Coracoid process, 5. Acromion),   6. Humerus;   Joints: 7. Acromioclavicular (AC), 8. Glenohumeral;  9: Bursa;   10. Rotator cuff (with 11. Supraspinatus, 12. Subscapularis, 13. Infraspinatus, 14. Teres minor / Piccolo rotondo),  15. Biceps muscle