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:
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
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