Extensor Carpi Radialis Longus

Extensor Carpi Radialis Longus

The muscle indicated is the extensor carpi radialis longus.

The extensor carpi radialis longus muscle is one of 7 muscles located in the superficial compartment of the posterior forearm. The posterior forearm consists of a superficial and a deep compartment. The superficial compartment contains 7 muscles, whereas the deep compartment contains 5 muscles.

The superficial compartment of the posterior forearm includes the following 7 muscles:

  1. Brachioradialis
  2. Extensor carpi radialis longus
  3. Extensor carpi radialis brevis
  4. Extensor digitorum
  5. Extensor digiti minimi
  6. Extensor carpi ulnaris
  7. Anconeus

The muscles of the posterior compartment of the forearm originate from the lateral epicondyle of the humerus and the supraepicondylar ridge and they are all innervated by the radial nerve, they generally extend the wrist joint.

Origin: Lateral supracondylar ridge of humerus

Insertion: Base of 2nd metacarpal

Action: Extends and abducts wrist

Innervation: Radial nerve

Learn more about the anatomy of the forearm muscles in this tutorial