Anatomy of the extensor digitorum Muscle ; Overview, Origin, Insertion, Function, Location, Nerve

The extensor digitorum is the primary muscle responsible for extending the medial four fingers (index to little finger) and also assists in wrist extension. It originates from the lateral epicondyle of the humerus and inserts into the extensor expansions of digits 2–5. 🩺 Anatomy of the Extensor Digitorum Origin Lateral epicondyle of the humerus via the common extensor tendon. Also arises from the antebrachial fascia and intermuscular septa. Insertion Divides into four tendons in the distal forearm. Passes deep to the extensor retinaculum. Inserts into the extensor expansions (hoods) of digits 2–5, attaching to both middle and distal phalanges. Course & Relations Located in the posterior compartment of the forearm (superficial layer). Runs alongside extensor carpi radialis brevis, extensor digiti minimi, and extensor carpi ulnaris. Tendons are interconnected by oblique intertendinous connections, limiting independent finger extension. Innervation Supplied by the posterior interosseous nerve (branch of radial nerve, C7–C8). Blood Supply Posterior interosseous artery Anterior interosseous artery Radial recurrent artery Action Finger extension at metacarpophalangeal and interphalangeal joints (digits 2–5). Wrist extension (assists extensor carpi muscles). Stabilizes fingers during flexion of the wrist. #Muscle