Extensor carpi radialis longus

Extensor carpi radialis longus
Superficial muscles of the forearm. Extensor carpi radialis longus visible in blue.
Transverse section across the wrist and digits. (Ext. carp. rad. long. labeled at center left.)
Details
Origin	lateral supracondylar ridge
Insertion	2nd metacarpal
Artery	radial artery
Nerve	radial nerve
Actions	extensor at the wrist joint, abducts the hand at the wrist
Antagonist	Flexor carpi ulnaris muscle
Identifiers
Latin	musculus extensor carpi radialis longus
TA	A04.6.02.040
FMA	38494
Anatomical terms of muscle []

The extensor carpi radialis longus is one of the five main muscles that control movements at the wrist. This muscle is quite long, starting on the lateral side of the humerus, and attaching to the base of the second metacarpal bone (metacarpal of the index finger).

It originates from the lateral supracondylar ridge of the humerus, from the lateral intermuscular septum, and by a few fibers from the lateral epicondyle of the humerus.

The fibers end at the upper third of the forearm in a flat tendon, which runs along the lateral border of the radius, beneath the abductor pollicis longus and extensor pollicis brevis; it then passes beneath the dorsal carpal ligament, where it lies in a groove on the back of the radius common to it and the extensor carpi radialis brevis, immediately behind the styloid process.

One of the three muscles of the radial forearm group, it initially lies beside the brachioradialis, but becomes mostly tendon early on. Passing between the brachioradialis and the extensor carpi radialis brevis, this tendon continues into the second tendon compartment together with the latter muscle.

It is inserted into the dorsal surface of the base of the second metacarpal bone, on its radial side.