Extensor carpi radialis brevis muscle

Last revised by Daniel J Bell on 16 Jan 2021

Extensor carpis radialis brevis (ECRB) muscle is a muscle of the superficial layer of the posterior compartment of the forearm. It passes through the 2nd extensor compartment of the wrist. Extensor carpi radialis brevis muscle is one of the three muscles forming the mobile wad of Henry. It is one of the extrinsic muscles of the hand.


  • origin: lateral epicondyle of the humerus, annular ligament of the radius
  • insertion: base of 3rd metacarpal on posterior surface with direct relationship with ECRL which inserts into the base of 2nd metacarpal
  • innervation: deep branch of radial nerve, C7, C8
  • action: extension and abduction of the wrist joint; extensor carpi radialis brevis muscle is a prime extensor of the wrist

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: extensor compartments of the wrist
    Drag here to reorder.