Drop wrist is associated with injury to which nerve?

Drop wrist is associated with injury to which nerve?

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

Answer: (C)

Drop wrist occurs when the radial nerve is injured because this nerve powers the extensor muscles of the wrist and fingers. Without these extensors working, the wrist cannot stay extended and instead falls into flexion, giving the appearance of a “dropped” wrist. This injury is classically seen with trauma to the humeral shaft where the radial nerve travels in the radial groove, or with damage to its distal branches that supply the forearm extensors. In contrast, injury to the ulnar or median nerves affects hand intrinsic muscles, thumb opposition, or forearm sensation in different patterns, not the ability to extend the wrist. Axillary nerve damage affects shoulder abduction by weakening the deltoid.

Drop wrist occurs when the radial nerve is injured because this nerve powers the extensor muscles of the wrist and fingers. Without these extensors working, the wrist cannot stay extended and instead falls into flexion, giving the appearance of a “dropped” wrist. This injury is classically seen with trauma to the humeral shaft where the radial nerve travels in the radial groove, or with damage to its distal branches that supply the forearm extensors.

In contrast, injury to the ulnar or median nerves affects hand intrinsic muscles, thumb opposition, or forearm sensation in different patterns, not the ability to extend the wrist. Axillary nerve damage affects shoulder abduction by weakening the deltoid.