Which muscles extend the wrist?

Which muscles extend the wrist?

• A. Extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris.
• B. Extensor carpi ulnaris and extensor digitorum.
• C. Extensor carpi radialis longus and brevis.
• D. Extensor digitorum and extensor carpi ulnaris.

Answer: (A)

Wrist extension is produced by muscles that run along the back of the forearm and attach to the bases of the metacarpal bones. When these muscles contract, they pull the back of the hand up, extending the wrist at the radiocarpal joint. The three main players are the extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris. The longus and brevis run along the radial (thumb) side and primarily extend the wrist, with some contribution to radial deviation. The extensor carpi ulnaris runs along the ulnar (pinky) side and also extends the wrist, adding a bit of ulnar deviation. Extensor digitorum mainly extends the fingers and only assists with wrist extension when the fingers are fixed or during certain grip tasks, so it’s not the best choice for defining wrist extension. That’s why the trio of extensor carpi muscles best fits the action of extending the wrist.

Wrist extension is produced by muscles that run along the back of the forearm and attach to the bases of the metacarpal bones. When these muscles contract, they pull the back of the hand up, extending the wrist at the radiocarpal joint.

The three main players are the extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris. The longus and brevis run along the radial (thumb) side and primarily extend the wrist, with some contribution to radial deviation. The extensor carpi ulnaris runs along the ulnar (pinky) side and also extends the wrist, adding a bit of ulnar deviation.

Extensor digitorum mainly extends the fingers and only assists with wrist extension when the fingers are fixed or during certain grip tasks, so it’s not the best choice for defining wrist extension. That’s why the trio of extensor carpi muscles best fits the action of extending the wrist.