The Extensor carpi radialis brevis muscle reference article from the English Wikipedia on 24-Jul-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Extensor carpi radialis brevis muscle

Sponsorship the way you would do it
Extensor carpi radialis brevis is an extensor, and an abductor of the hand at the wrist joint.

It lies medial to longus, and is slightly shorter. It starts lower down on the humerus at the lateral epicondyle, and inserts into the base of the 3rd metacarpal.

Like all the muscles in the posterior forearm, ECR brevis is supplied by a branch of the radial nerve.