Extensor Carpi Ulnaris
The structure indicated is the extensor carpi ulnaris muscle of the forearm. The extensor carpi ulnaris muscle is one of 7 muscles located in the superficial compartment of the posterior forearm. The posterior forearm consists of a superficial and a deep compartment. The superficial compartment contains 7 muscles, whereas the deep compartment contains 5 muscles. The superficial compartment of the posterior forearm includes the following 7 muscles:- Brachioradialis
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Anconeus
Origin: lateral epicondyle of humerus and posterior border of ulna
Insertion: base of 5th metatarsal
Action: extension and abduction of wrist
Innervation: Posterior interosseous nerve
Learn more about the anatomy of the forearm muscles in this tutorial.