Extensor Carpi Radialis Brevis

• Click here for access to the full Anatomy Glossary.
• Right click on the image for a downloadable file of this muscle.
• Use of this artwork requires proper credit to be given (Permission: Dr. Joe Muscolino. www.learnmuscles.com – art work Giovanni Rimasti)

The Extensor Carpi Radialis Brevis is in the Superficial Layer of the Posterior Compartment of the forearm. It is also a member of the Wrist Extensor Group; the muscles of the wrist extensor group are:

• Extensor carpi radialis longus
• Extensor carpi radialis brevis
• Extensor carpi ulnaris

ATTACHMENTS:

• Lateral epicondyle of the humerus via the common extensor belly/tendon to the radial side of the posterior hand.
  • The distal attachment is onto the posterior side of the base of the third metacarpal.

ACTIONS:

• Extends the hand at the wrist joint.
• Radially deviates the hand at the wrist joint.
• Flexes the forearm at the elbow joint.

NOTES:

1. The extensor carpi radialis brevis is also a member of the Radial Group of forearm muscles (along with the brachioradialis and extensor carpi radialis longus).
2. The extensor carpi radialis brevis is often involved with lateral elbow tendinopathy (aka tennis elbow).
3. The extensor carpi radialis brevis crosses the elbow joint anteriorly so it flexes the elbow joint, but crosses the wrist joint posteriorly so it extends the wrist joint.