Shoulder Anatomy
The anterior view of the shoulder shows the rotator cuff muscles and tendons, and the long white tendon going downward is the biceps tendon. The bone to the right is the arm bone, the humerus.
This anterior view shows the ligaments, or capsule, of the shoulder. It is these ligaments that can get too loose or too tight in the thrower's shoulder and cause problems
This view of the inside of the joint shows how small the socket really is. It is the ligaments and the rotator cuff that hold the ball in the socket. The outer, thicker layer of white is the rotator cuff. The thinner, more solid inner layer is the capsule and ligaments. You can see the red biceps tendon attaches to the red circle, which is the labrum.
This view shows another look at the inside, with the socket in the center. The ligament labelled "A" is the posterior inferior glenohumeral ligament. It gets very tight in throwers and causes the majority of problems throwers have.