Extensor carpi radialis longus
Musculus extensor carpi radialis longus
Also known as: ECRL
A superficial extensor from the lateral supracondylar ridge to the base of the 2nd metacarpal. It extends and abducts the wrist and is essential for a firm grip.
Overview
ECRL arises from the distal third of the lateral supracondylar ridge, just below brachioradialis. Its tendon descends in the 2nd extensor compartment with ECRB, is crossed by APL, EPB and EPL, and inserts on the dorsal surface of the base of the 2nd metacarpal. With ECRB it extends and abducts (radially deviates) the wrist. It is especially active in clenching the fist, where it prevents the wrist from flexing under the pull of the finger flexors. Because it is supplied by the radial nerve proper, above the elbow, it is spared in posterior interosseous nerve lesions.
Anatomy
- Origin
Distal third of the lateral supracondylar ridge of the humerus.
- Insertion
Dorsal surface of the base of the 2nd metacarpal.
- Action
Extension and abduction (radial deviation) of the wrist.
- Innervation
Radial nerve.
- Nerve roots
C6–C7
- Arterial supply
Radial artery and radial recurrent artery.
Function
- Extends the wrist
- Abducts (radially deviates) the wrist
- Stabilises the wrist during gripping
Clinical significance
Intersection syndrome
Inflammation where APL and EPB cross over ECRL and ECRB, about 4–6 cm above the wrist. It causes crepitus and pain in rowers and canoeists.
Compiled from standard anatomy and physiology references — see the Muscular System sources. For education only; not medical advice.