Claw hand deformity is commonly associated with injury to which nerve?

Claw hand deformity is commonly associated with injury to which nerve?

• A. Radial nerve
• B. Ulnar nerve
• C. Median nerve
• D. Axillary nerve

Answer: (B)

Claw hand occurs when the intrinsic muscles of the hand that are supplied by one nerve are paralyzed, disrupting the balance between flexion and extension around the fingers. The ulnar nerve supplies the interossei along with the medial two lumbricals, which normally flex the metacarpophalangeal joints and extend the finger joints (the interphalangeal joints). When these intrinsic muscles are lost due to ulnar nerve injury, the extrinsic extensors and flexors no longer work together to position the fingers properly, leading to hyperextension at the metacarpophalangeal joints and flexion at the interphalangeal joints—especially in the ring and little fingers—giving the claw-like appearance. The loss of interossei also impairs finger abduction and adduction, worsening the deformity. In contrast, radial nerve injury primarily causes wrist and finger extension weakness (wrist drop), median nerve injury creates other patterns like hand of benediction with loss of thenar function, and axillary nerve injury affects shoulder movement. Therefore, claw hand is most closely associated with injury to the ulnar nerve.

Claw hand occurs when the intrinsic muscles of the hand that are supplied by one nerve are paralyzed, disrupting the balance between flexion and extension around the fingers. The ulnar nerve supplies the interossei along with the medial two lumbricals, which normally flex the metacarpophalangeal joints and extend the finger joints (the interphalangeal joints). When these intrinsic muscles are lost due to ulnar nerve injury, the extrinsic extensors and flexors no longer work together to position the fingers properly, leading to hyperextension at the metacarpophalangeal joints and flexion at the interphalangeal joints—especially in the ring and little fingers—giving the claw-like appearance. The loss of interossei also impairs finger abduction and adduction, worsening the deformity. In contrast, radial nerve injury primarily causes wrist and finger extension weakness (wrist drop), median nerve injury creates other patterns like hand of benediction with loss of thenar function, and axillary nerve injury affects shoulder movement. Therefore, claw hand is most closely associated with injury to the ulnar nerve.