In this three-part series we'll be talking about the shoulder, its anatomy, mechanics, a couple of typical injuries, and prevention methods for keeping your shoulders happy. The shoulder is the most mobile joint in your body, and at the same time one of the most unstable, making it vulnerable to injury, but can be trained properly to prevent future issues. Imagine a golf ball on a tee, and there you have the head of the humerus (golf ball) sitting on an almost flat scapular glenoid (tee). Now, our bodies have been designed intelligently, so to increase the surface on which the head of the humerus lies, there is a ring of fibrous-cartilage tissue cupping the "golf ball" so it can't get knocked off the "tee" as easily. This is the labrum. The "golf ball" is kept on the "tee" with the help of some ligaments, shoulder capsule and the tendons of a few muscles, mainly the rotator cuff muscles: Subscapular, Infraspinatus, Supraspinatus and Teres Minor/Major. As you see in the figure above left, the long head of the biceps anchors into, and becomes part of the labrum. That connection right there will provoke one of the most feared injuries in the shoulder, and we'll tell you all you need to know about it and more soon. Stay tuned for parts II and III of Inside the Shoulder: Anatomy, Problems and Prevention.