Dance Anatomy & Kinesiology

462 Dance Anatomy and Kinesiology

FIGURE 7.61 Superficial muscles of the right arm. (A) Anterior view, (B) posterior view.

extension. The proximal and distal radioulnar joints

are pivot joints that allow the crossing over of the

distal end of the radius relative to the distal ulna in

the specialized movements of pronation and supina-

tion of the forearm. The wrist joint is a condyloid

joint allowing flexion, extension, radial deviation,

and ulnar deviation. One of the primary functions

of these joints as a group is to position the hand.

The hand is designed for rapid mobility and preci-

sion with its complex array of joints and muscles.

One of the unique properties of the hand is the

ability to perform opposition, a function essential

for grasping and manipulation of objects. Many

muscles cross these joints to produce movement; and

due to the many multijoint muscles in this region,

relative positioning of the joints crossed by these

muscles will influence which muscles are used and

the amount of torque the muscle can generate in a

given movement.

With the relatively weak structural design of the

upper extremity, muscular strength is essential not

only for providing stability but also for helping

prevent injuries in this region. Although the preva-

lence of upper extremity injuries in many dancers

is markedly less than that for the lower extremity,

injury incidence is on the rise, at least in some dance

forms. With increased choreographic demands on the

upper extremity, it is important that dancers perform

supplemental strengthening to both enhance their

technique and lower the risk of injury. In some cases,

performing stretches for the shoulder is also desirable.

When injuries do occur, a good medical diagnosis and

treatment are important to prevent frozen shoulder,

chronic conditions, and injury recurrence.