Deep Fascia of the Lower Arm, Posterior View

Description

Posteriorly, the deep fascia (antebrachial fascia) forms a dense aponeurotic sheath around the forearm, lying superficial to the extensor compartment and blending distally with the dorsal wrist retinaculum over the radiocarpal region. Beneath this fascial sleeve, the superficial extensors occupy the central and lateral posterior forearm, with extensor digitorum and extensor carpi ulnaris positioned more ulnarly and extensor carpi radialis longus and brevis tracking along the lateral (radial) border toward the base of the metacarpals. Distal tendons converge into pale longitudinal cords that pass deep to the extensor retinaculum and fan across the dorsum of the hand toward the digits; superficial dorsal veins may be suggested in blue over the fascia. A posterior view of the deep fascia matters because it explains why dorsal forearm swelling behaves differently from a superficial hematoma and how restrictive fascial boundaries contribute to compartment physiology. Fascial thickening and its septal attachments to the radius and ulna help define the extensor compartment, a practical frame for teaching compartment syndrome in the forearm and for planning dorsal approaches that split fascia longitudinally to reduce tension and protect superficial sensory nerves. Short and unforgiving. Educators use this view to anchor lessons on the antebrachial fascia, extensor tendon routing under the retinacula, and the surface anatomy that guides dorsal wrist injections, tendon repairs, and decompression incisions. It also fits well in orthopaedic and hand surgery atlases when illustrating extensor tendon compartments and postoperative scarring planes in a male forearm. Anatomical accuracy verified by SciePro's Medical Advisory Board.