The extensor carpi radialis brevis is a muscle of the forearm which belongs to the lateral group of extensor muscles. It lies on the radial and lateral aspect of forearm. It is slightly and proximally covered by the extensor carpi radialis longus; distally, it is crossed over by the abductor pollicis longus and extensor pollicis brevis muscle.
The extensor carpi radialis brevis muscle arises from the lateral humeral epicondyle and the collateral and annular ligaments. Then it runs downwards along the length of forearm, ending up in a tendon, which travels through the synovial sheath of the tendons of the radial extensors of wrist. It is inserted into the base of the third metacarpal bone.
Action
This muscle extends the hand at the wrist joint, abducting it a little.
Nerve Supply
The extensor carpi radialis brevis is innervated by branches of the radial nerve (C5, C6, C7).
Blood Supply
It receives oxygen-rich blood from the deep brachial (profunda brachii) and the recurrent radial artery.
Below, the extensor muscles of the forearm, showing the extensor carpi radialis brevis.
