Name
Pronunciation
(eks-TEN-sor KAR-pi ra-de-A-lus BREV-is)
Origin/Proximal Attachment
Lateral epicondyle via the common extensor tendon; radial collateral ligament; antebrachial fascia
Insertion/Distal Attachment
Base of 3rd metacarpal
Action/Relevance
Extends the hand at the wristRadially deviates the hand at the wrist
Innervation
Radial nerve - deep branch (C7,8)
Notes
Extensor carpi radialis brevis originates from the common extensor origin on the anterior aspect of the lateral epicondyle of the humerus. It inserts into dorsal base of the third metacarpal having traversed the extensor retinaculum.
The action of extensor carpi radialis brevis is to extend and radially-deviate the wrist.
It is supplied by the radial nerve via the posterior interosseous nerve, a branch of the radial nerve (C7,C8).