Extensor carpi radialis longus

The extensor carpi radialis longus (Latin: musculus extensor carpi radialis longus) is a long superficial muscle of the forearm that extends between the humerus and the second metacarpal bone. It belongs to the lateral compartment of the forearm muscles. The extensor carpi radialis longus lies between the brachioradialis and extensor carpi radialis brevis muscles on the radial side of the forearm.

Origin

The extensor carpi radialis longus muscle originates from the lateral supracondylar ridge of the humerus and lateral intermuscular septum of the arm.

Insertion

The extensor carpi radialis longus descends and inserts on the base of the second metacarpal bone.

Action

The extensor carpi radialis longus muscle provides the extension and abduction of the hand at the wrist joint.

Innervation

The extensor carpi radialis longus is innervated by the radial nerve (C5 - C8) - a branch of the brachial plexus.

Blood supply

The extensor carpi radialis longus muscle receives arterial blood supply from the radial recurrent, radial collateral and radial arteries. The radial recurrent artery is a branch of the radial artery, while the radial collateral artery arises from the deep brachial artery.