Extensor indicis muscle

Synonym: extensor of the index finger, extensor indicis, extensor indicis proprius muscle
German: Musculus extensor indicis

1 Definition

The extensor indicis muscle belongs to the deep layer of the forearm extensors.

2 Devolution

Its origin lies in the posterior surface of the ulna and in the interosseous membrane of the forearm, below the origin of the extensor pollicis longus muscle. Its tendon pierces the 4th tendon compartment extensor retinaculum and inserts in the dorsal aponeurosis of the index finger together with the tendon of the extensor digitorum muscle.

3 Innervation

Its innervation is provided by the profound branch of the radial nerve, with fibers from the C7 and C8 segments.

4 Function

The extensor indicis muscle effects an extension of the index finger.