Posterior Forearm (Extensor Compartment)

The posterior forearm holds the extensors and supinator — ALL supplied by the radial nerve (mostly its deep/posterior interosseous branch). Most arise from the common extensor origin (lateral epicondyle). SUPERFICIAL LAYER (lateral epicondyle, except brachioradialis above it) • Brachioradialis (radial n. proper) — a flexor of the mid-prone forearm despite lying posteriorly. • Extensor carpi rad…