Shoulder Joint Anatomy - Section Three

Shoulder Joint Anatomy - Section 3

As opposed to the hip joint (a true ball and socket joint), the shoulder joint is a much shallower joint, and offers less structural support than is seen in the hip. The shoulder joint's anatomy has sometimes been compared to that of a golf ball and golf tee, with the head of the humerus being compared to the golf ball, and the scapula's glenoid fossa being the tee. The cross-sectional MRI of the shoulder joint, as seen below, shows this unique anatomical relationship in detail.

The illustration on the right depicts a lateral or side view of the scapula, showing the glenoid fossa and the soft tissue ring around it called the glenoid labrum. For clarity the humerus has been removed in this figure in order to show the joint capsule and muscles of the rotator cuff more clearly.

With the humeral head removed, one can readily see the location of the many soft tissue structures that make up the shoulder joint. Because of the lack of bone support in this shallow joint, the soft tissue element's importance cannot be overstated. It is evident that these structures add a great deal of stability to this unique joint.

Of particular interest are the biceps tendon (1), the various joint ligaments (2 through 6), three elements of the shoulder joint's Rotator Cuff (A, B, & C), and the glenoid labrum that surrounds the fossa.

Our web section called: Understanding Shoulder X-rays and MRIs will provide additional information about the use of these two modalities in shoulder evaluations.

LEGEND FOR THE ABOVE FIGURE:

A = Supraspinatus Muscle
B = Infraspinatus Muscle
C = Subscapularis Muscle

1 = Biceps Tendon
2 = Superior Glenohumeral Joint Ligament
3 = Middle Gleno-humeral Joint Ligament
4 = Anterior Band of Inferior Glenohumeral Lig.
5 = Posterior Band of Inferior Glenohumeral Lig.
6 = Axillary Pouch of Inferior Glenohumeral Lig.

* The humerus has been removed.

Because of the shoulder's importance in our work, leisure-time activities, and recreation, and athletic activities, any problem or painful condition affecting the shoulder is cause for concern. Athletes of all ages and skill levels may experience shoulder problems ranging from simple overuse, to more severe injuries. Ahlfeld Sports Medicine is experienced in the evaluation and treatment of all types of these shoulder problems, and will assist each patient in getting back in their game.

For a careful and thorough evaluation of your shoulder problem by Dr. Ahlfeld,
contact Ahlfeld Sports Medicine in Indianapolis.