The forearm (antebrachium) consists of the radius and ulna. Proximally, the forearm articulates with the humerus through the elbow complex (humeroulnar and humeroradial joints). Distally, the forearm articulates with the carpal bones through the wrist complex, enabling a wide array of actions. Forearm muscles are organized into two fascial compartments, similar to those of the arm muscles. The anterior compartment contains flexor muscles (innervated by the median and ulnar nerves). The posterior compartment contains extensor muscles (innervated by the radial nerve).
The wrist complex allows for motion in two planes (Figure 32-1A):
Flexion. Wrist bends anteriorly.
Extension. Wrist bends posteriorly.
Radial deviation (abduction). Wrist abducts toward the radius.
Ulnar deviation (adduction). Wrist adducts toward the ulna.
A. Actions of the wrist joint. Superficial (B), intermediate (C), and deep (D) muscles of the anterior forearm.
FOREARM MUSCLES OF THE ANTERIOR COMPARTMENT
The muscles in the anterior compartment of the forearm have the following in common:
The muscles in the anterior compartment of the forearm are divided into three groups: superficial, intermediate, and deep.