index extensor muscle

n.

A muscle with origin from the dorsal surface of the ulna, with insertion to the dorsal extensor aponeurosis of the index finger, with nerve supply from the radial nerve, and whose action assists in extending the forefinger.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.