The shoulder is an amazing structure that allows you to powerfully push and pull from almost any angle. The shoulder is all the structures that allow this articulation, including the Humerus (funny bone), Scapula (shoulder blade), Clavicle (collar bone) and all associated tissues. Many very powerful muscles attach at the shoulder such as the Lats, Biceps, Triceps, Pecs, and Delts. The rotator cuff is actually four separate muscles that stabilize the shoulder: the Teres Minor, Supraspinatus, Infraspinatus, and Subscapularis. A torn Rotator Cuff is usually a tear to the tendons where these muscles attach to the head of the Humerus.