Extensor Indicis Proprius Muscle

**Semantic type:** Body Part, Organ, or Organ Component

**Definition:** A muscle in the posterior forearm that originates from the posterior surface of the ulna and attaches to the base of the second proximal phalanx and the tendon of the extensor digitorum muscle; it functions to extend the second digit at metacarpophalangeal and interphalangeal joints.

**Synonyms:** - EXTENSOR INDICIS PROPRIUS MUSCLE