Dance Anatomy & Kinesiology

The Upper Extremity 461

FIGURE 7.60 (A) Bones and (B) joints of the upper extremity (right side, anterior view).

skeleton only at the sternoclavicular joint. This very
mobile structure can perform elevation, depression,
abduction, adduction, upward rotation, and down-
ward rotation in order to optimize the relationship of
the glenoid cavity to the head of the humerus during
the desired movement of the humerus. The shoulder
joint is the most mobile ball-and-socket joint in the
human body, naturally allowing for a large range
of motion in flexion, extension, abduction, adduc-
tion, external rotation, and internal rotation. Many

muscles assist with these movements and can be

functionally divided into three groups: the scapular

muscles, rotator cuff, and other major glenohumeral

muscles. In addition to producing the movements

of the shoulder, these muscles function to give this

structurally weak joint stability, maintain correct

alignment, and foster correct mechanics for the SIT

force couple and the scapulohumeral rhythm.

Moving distally from the shoulder joint, the elbow

joint functions as a hinge joint allowing flexion and

Glenohumeral joint/

shoulder (ball-and socket)

Elbow joint

(hinge)

http://www.ebook3000.com