Summary
Origins
- Lateral epicondyle of the 🦴 humerus
- Posterior border of the 🦴 ulna
Insertions
- Base of the 5th metacarpal
Actions
- Wrist extension
- Ulnar deviation (adduction) of the wrist
The extensor carpi ulnaris runs along the ulnar side of the posterior forearm. It arises from the lateral epicondyle of the humerus and the posterior ulna. Its tendon crosses the dorsal wrist to insert on the base of the fifth metacarpal, allowing the hand to extend and move toward the ulna.
It shares a common origin with extensor digitorum and extensor digiti minimi. Working with extensor carpi radialis longus and extensor carpi radialis brevis it steadies the wrist during gripping. It opposes flexor carpi ulnaris when the wrist bends.
Related Muscles
- extensor carpi radialis longus
- extensor carpi radialis brevis
- flexor carpi ulnaris
- extensor digitorum
- extensor digiti minimi