Which muscles contribute to ulnar deviation of the wrist (bending toward the ulna/pinky)?

Which muscles contribute to ulnar deviation of the wrist (bending toward the ulna/pinky)?

• A. Flexor carpi ulnaris and extensor carpi ulnaris
• B. Extensor carpi radialis longus
• C. Abductor pollicis longus
• D. Flexor digitorum profundus

Answer: (A)

Ulnar deviation is movement of the wrist toward the pinky side. The muscles that pull the wrist toward the ulna are the two on the ulnar side crossing the wrist: flexor carpi ulnaris and extensor carpi ulnaris. Flexor carpi ulnaris flexes and adducts the wrist, attaching to the pisiform and the base of the 5th metacarpal. Extensor carpi ulnaris extends and adducts the wrist, attaching to the base of the 5th metacarpal. When they contract together, they move the hand toward the ulna. Extensor carpi radialis longus, by contrast, lies on the radial (thumb) side and mainly contributes to wrist extension and radial deviation, not ulnar deviation. Abductor pollicis longus acts on the thumb and doesn’t primarily affect wrist deviation. Flexor digitorum profundus flexes the fingers and has little direct effect on wrist deviation.

Ulnar deviation is movement of the wrist toward the pinky side. The muscles that pull the wrist toward the ulna are the two on the ulnar side crossing the wrist: flexor carpi ulnaris and extensor carpi ulnaris. Flexor carpi ulnaris flexes and adducts the wrist, attaching to the pisiform and the base of the 5th metacarpal. Extensor carpi ulnaris extends and adducts the wrist, attaching to the base of the 5th metacarpal. When they contract together, they move the hand toward the ulna.

Extensor carpi radialis longus, by contrast, lies on the radial (thumb) side and mainly contributes to wrist extension and radial deviation, not ulnar deviation. Abductor pollicis longus acts on the thumb and doesn’t primarily affect wrist deviation. Flexor digitorum profundus flexes the fingers and has little direct effect on wrist deviation.