The extensor carpi radialis brevis is a muscle located within the superficial compartment of the posterior forearm. This muscle, due to its lateral position in the forearm, is responsible for producing both abduction and extension at the wrist. It does this through the tendon of the extensor carpi radialis brevis, which passes through the 2nd extensor compartment at the wrist.
The extensor carpi radialis brevis is connected to the lateral epicondyle of the humerus, which is the protrusion directly below the elbow joint on the outside of the elbow. It then attaches itself to the base of the third metacarpal bone. The actions of this muscle are mainly responsible for extension and abduction at the wrist, which it facilitates by drawing upon the motor units of the radial nerve.
The extensor carpi radialis brevis is supplied by the radial artery, which is a major artery of the forearm. It is located medially to the brachioradialis and divides into the deep and superficial branches, with the superficial branch supplying the extensor carpi radialis brevis with the axial blood that it needs to properly function.
Figure 1 below shows the various muscles located in the superficial layer of the posterior forearm. It includes the extensor carpi radialis brevis, as well as the extensor digitorum and the extensor carpi ulnaris.
The extensor carpi radialis brevis is an important muscle to consider when looking into the anatomy of the forearm. It is responsible for the actions of abduction and extension at the wrist, as well as providing the necessary axial blood supply to the other muscles in the forearm. It is a part of the superficial compartment of the posterior forearm and is connected to the lateral epicondyle of the humerus as well as the base of the third metacarpal bone. It is supplied by the radial nerve and the radial artery.
Overall, the extensor carpi radialis brevis is a vital muscle of the forearm that should not be overlooked when looking into the anatomy of the lower arm. It is important to understanding how the forearm moves, and is essential when looking into any conditions or injuries that can affect the forearm.
