Extensor carpi radialis longus

Anatomy

Origin:
Distal third of lateral supracondylar ridge of humerus and lateral intermuscular septum.

Insertion:
Posterior aspect of base of second metacarpal.

Key Relations:
One of the four muscles in the superficial posterior compartment of the forearm.

Functions

-Extends the hand at the wrist joint.
-Abducts the hand at the wrist (radial deviation) particularly when acting together with flexor carpi radialis and extensor carpi radialis brevis.
E.g. any activity alternating between flexion with ulnar deviation (flexor carpi ulnaris) and extension with radial deviation such as hammering a nail or playing tennis..

Supply

Nerve Supply:
Radial nerve (C6,C7).

Blood Supply:
Radial artery.

Clinical

Rheumatoid arthritis in the hand is characterised by a zigzag pattern of deformity where ulnar deviation of the metacarpophalangeal joints is accompanied by radial deviation of the wrist. This deformity is sometimes treated by tendon transfer of extensor carpi radialis longus to extensor carpi ulnaris.

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