The posterior interosseous nerve supplies the remaining muscles in the posterior compartment and terminates as articular branches, which pass deep to the extensor pollicis longus muscle to reach the wrist.
The hand (Fig. 7.93) is the region of the upper limb distal to the wrist joint. It is subdivided into three parts: the wrist (carpus), the metacarpus, and the digits (five fingers including the thumb).