The extensor digiti minimi (extensor digiti quinti proprius) is a slender muscle of the forearm, placed on the ulnar side of the extensor digitorum communis, with which it is generally connected.

It arises from the common extensor tendon by a thin tendinous slip and frequently from the intermuscular septa between it and the adjacent muscles.

Its tendon passes through a compartment of the extensor retinaculum, posterior to distal radio-ulnar joint, then divides into two as it crosses the dorsum of the hand, and finally joins the extensor digitorum tendon.

The extensor digiti minimi is a two joint muscle.

This article incorporates text in the public domain from page 451 of the 20th edition of Gray's Anatomy (1918)