DEPICTING THE ARM SIDE VIEW

DEPICTING THE ARM SIDE VIEW

Bones Here the arm is not viewed in full profile; rather it is seen from an angle that is a combination of a side view and a back view. Because of the angle, the bony landmarks most apparent under the muscle are the olecranon, outer epicondyle, and head of ulna. 

Muscles The side view provides a good angle for observing the extensors and flexors of the upper and lower arm. The brachioradialis, located where the upper and lower arms meet, is particularly important. It originates on the lateral side of the humerus (C), above the outer epicondyle (E), and then attaches to the lateral side of the wrist above the head of radius (I). 

The brachia radialis is responsible for turning the palm up (supinate), and the pronator teres (see page 30) for turning the palm down (pronate). The radius (shaded) rotates around the fixed ulna, permitting pronation and supination of the palm.

The span between the inside bend of the elbow and the wrist is usually about one hand length. The arrows show the inward and outward curvature of the muscles, and the dashed line shows the line of the ulna, called the "ulnar furrow."