Extensor Carpi Radialis Brevis
The structure indicated is the extensor carpi radialis brevis muscle of the forearm. The extensor carpi radialis brevis 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
Insertion: base of 3rd metacarpal
Action: Extends and abducts wrist
Innervation: Radial nerve
Learn more about the muscles of the forearm in this tutorial.