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Understanding Shoulder Pain

The shoulder is composed of three bones: the upper arm bone (humerus), the shoulder blade (scapula), and the collarbone (clavicle). The top of the upper arm bone fits into a rounded socket in the shoulder blade. The socket is known as the glenoid. The muscles and tendons keep the arm bone centered in the shoulder socket. The tissues are known as the rotator cuff and cover the top of the upper arm bone and attach it to the shoulder blade.

Shoulder problems typically involve the soft tissues such as muscle, tendon or ligament. Most issues can be placed into two major categories, instability or rotator cuff (i.e. impingement).