Dorsal Hand Interosseous Muscle

**Semantic type:** Anatomical Structure

**Definition:** Four muscles in the hand between the metacarpal bones originating on the radial side of the metacarpal as well as the ulnar side of the previous metacarpal. The second and third interosseous muscles are inserted into the third proximal phalanx while the first is inserted into the second proximal phalanx and the fourth is inserted into the fourth proximal phalanx. These muscles act to abduct the fingers away from the middle finger.