Extensor Carpi Radialis Longus

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The Extensor Carpi Radialis Longus is in the Superficial Layer of the Posterior Compartment of the forearm. It is also a member of the Wrist Extensor Group; the muscles of the wrist extensor group are:

• Extensor carpi radialis longus
• Extensor carpi radialis brevis
• Extensor carpi ulnaris

ATTACHMENTS:

• Lateral supracondylar ridge of the humerus to the radial side of the posterior hand.
  • The proximal attachment is onto the distal 1/3 of the lateral supracondylar ridge.
  • The distal attachment is onto the posterior side of the base of the second metacarpal.

ACTIONS:

• Extends the hand at the wrist joint.
• Radially deviates the hand at the wrist joint.
• Flexes the forearm at the elbow joint.

NOTES:

1. The extensor carpi radialis longus is also a member of the Radial Group of forearm muscles (along with the brachioradialis and extensor carpi radialis brevis).
2. The extensor carpi radialis longus crosses the elbow joint anteriorly so it flexes the elbow joint, but crosses the wrist joint posteriorly so it extends the wrist joint.