Muscle
Extensor carpi radialis longus
Long radial wrist extensor
High-yield
Its motor branch usually leaves the radial nerve before that nerve divides. This explains why its function can remain when the posterior interosseous nerve is damaged.
Overview
This superficial forearm muscle links the lateral humerus to the second metacarpal. Together with other wrist muscles, it steadies the hand while the fingers work.
Reference facts
- Origin
- Distal part of the humeral lateral supracondylar ridge
- Insertion
- Dorsal base of the second metacarpal
- Action
- Extends the wrist and draws it toward the radius
- Innervation
- Radial nerve before its terminal division; chiefly C6-C7
- Blood supply
- Radial artery and its radial recurrent branch
Clinical correlation
In posterior interosseous neuropathy, this muscle can still extend the wrist. If extensor carpi ulnaris is weak, the extending hand may also drift toward the thumb side.
Frequently asked questions
What does the extensor carpi radialis longus do?
The extensor carpi radialis longus extends the wrist and draws it toward the radius.
What nerve innervates the extensor carpi radialis longus?
Radial nerve before its terminal division; chiefly C6-C7.
Where does the extensor carpi radialis longus attach?
The extensor carpi radialis longus originates from the distal part of the humeral lateral supracondylar ridge and inserts on the dorsal base of the second metacarpal.
What is the blood supply of the extensor carpi radialis longus?
The extensor carpi radialis longus is supplied by the radial artery and its radial recurrent branch.