Extensor indicis

Medically reviewed by Healthline Medical Team on January 23, 2015

The extensor indicis originates in the lower back of the ulna, just beneath the extensor pollicis longus. The interosseous membrane is next to it. The key role of the extensor indicis is to enable extension of the index finger. It also helps in extension of the midcarpal joints and the wrist. It is a thin, long muscle in the deeper layers of the dorsal forearm. Its tendon provides extension for the various index finger phalanges. The muscle travels across the fourth tendon compartment. The extensor digitorum runs parallel to it. The common trait between the extensor of the index finger and the extensor of the little finger is that in both cases the tendon travels along the ulnar part of the tendon of the extensor digitorum. Both the extensors are without the oblique bands that connect the extensor digitorum tendons on the dorsal part of the hand. The disjointed extensors of the index and little fingers enable these two fingers to move more freely than the remaining fingers.

CMS Id: 141456