Common finger extender

The common extensor muscle of the fingers is located in the posterolateral part of the forearm. It is a superficial muscle that originates from the posterior aspect of the lateral epicondyle of the humerus, from the lateral collateral ligament, from the annular radial ligament and from the antibrachial fascia. In the middle of the forearm it is divided into three bundles: the most lateral of the three gives rise to two tendons while the other two continue, respectively, in a single tendon. The four tendons are inserted on the dorsal face of the first phalanx (or proximal phalanx) and then divide into three tabs. The median tongue is fixed to the 2nd phalanx, while the lateral and medial tongue are inserted at the 3rd phalanx of the 2nd-5th finger. With its tendons it crosses the 4th dorsal carpal ligament duct; between the individual tendons are regularly present connections (intertendinee joints) that start from the 4th finger and that go towards the third and fifth finger.

Its main function is to extend and enlarge the fingers (excluding the thumb). It is the most efficient muscle in dorsal flexion of the hand and also participates in ulnar abduction.

It is innervated by the deep radial nerve (C6-C8). It is sprayed from the posterior interosseous artery.