Name

# Extensor Carpi Ulnaris

Pronunciation

(eks-TEN-sor KAR-pi ul-NAR-is)

Origin/Proximal Attachment

Lateral epicondyle via the common extensor tendon, posterior body of ulna & antebrachial fascia

Insertion/Distal Attachment

Base of 5th metacarpal (medial side)

Action/Relevance

Extends the hand at the wristUlnar deviation of the hand at the wrist

Innervation

Radial nerve - posterior interosseous (C6, 7,8)

Notes

Extensor carpi ulnaris is a muscle, located in the forearm of human bodies that acts to extend and adduct the wrist.

Being an extensor muscle, extensor carpi ulnaris is on the posterior side of the forearm. It attaches to the lateral epicondyle of the humerus, though it crosses the forearm to the ulnar (medial) side, and attaches to the base of the 5th metacarpal.

It is innervated by a branch of the radial nerve, namely the posterior interosseus nerve. Its arterial supply comes from the ulnar artery.