The shoulder complex, as the name implies, is a very complicated joint made up of numerous structures. The clavicle (collar bone), scapula, and humerus are the boney makeup of the shoulder complex. Great mobility is allowed at this ball-and-socket joint by the relationship between the humerus and the glenoid cavity of the scapula; the glenohumeral joint. This joint resembles a golf ball sitting on top of a tee, the head of the humerus being the ball and the glenoid cavity being the tee. Now if you imagine the ball and tee in front of you, its obvious that the ball could very easily find its way off of the tee. This being said, although great mobility is allowed at this joint, stability is greatly compromised. Athletes who perform repetitive forceful over the head movements such as pitchers, swimmers, tennis players, or volleyball players place a great deal of stress on the shoulder complex.
Unlike the ball and tee example, there are other forces at work to maintain the humeral heads position on the glenoid cavity. This joint is maintained by both static and dynamic stabilizers. The static component relates to the many ligaments of the shoulder and the glenoid labrum, a fibrocartilaginous rim that deepens the glenoid cavity. Acting as dynamic stabilizers are the muscles of the shoulder complex which includes the deltoid and the rotator cuff muscles. The rotator group is made up of the Supraspinatus, Infraspinatus, Teres minor, and the Subscapularis muscles (“SITS” muscles).In many of the before mentioned athletes and their respective motions, the dynamic and static stabilizers of the shoulder can become weakened and often times injured. Take a baseball pitcher for instance who may throw a few hundred innings in one season. Over time, the rotator cuff muscles, which act to eccentrically slow the arm down after releasing the ball, can become weakened and inflamed if not properly treated. Once these muscles are no longer able to perform their duties, the pitcher relies on other muscles such as the biceps tendon to do much of the heavy lifting. Proper icing, rest, stretching, and strengthening may help alleviate the pain.( http://www.youtube.com/watch?v=kDd6fwUgJIE, http://www.physioadvisor.com.au/8122150/shoulder-strengthening-exercises-shoulder-rehabi.htm )
Back to the ball on the tee example, you can imagine how easily the ball can fall of the tee with even the slightest of breezes. Unfortunately the same applies to the shoulder complex. All it takes is one perfect moment of positioning and contact for the humeral head to dislocate from the glenoid cavity. For the first time dislocation this may be pretty painful. A dislocation of the shoulder causes damage to the static and dynamic stabilizers mentioned earlier. In the case that the humeral head does not return to its original position on its own, medical attention needs to be sought immediately as blood and nerve supply may be affected. While rehabilitation can be prescribed to strengthen the dynamic stabilizers, once the static stabilizers are injured surgical intervention is the only way to restore them to pre-injury strength. Surgical intervention is an aggressive approach to treatment that should be saved for those who encounter repeated dislocations or subluxations only when all other treatment methods have been exhausted.
Hopefully you, the reader, never suffers any of these injuries, but in the case that you do, please seek medical evaluation and treatment from your physician or local hospital.