Injury causing hand weakness with sensory loss on the medial hand (inferior trunk of the ulnar nerve in the hand) involves which nerve?

Injury causing hand weakness with sensory loss on the medial hand (inferior trunk of the ulnar nerve in the hand) involves which nerve?

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

Answer: (C)

The ulnar nerve is involved. It supplies most of the intrinsic hand muscles (especially the interossei and the medial two lumbricals) and provides sensation to the medial aspect of the hand (including the little finger and the medial half of the ring finger). When this nerve is injured, you get weakness in the intrinsic hand muscles plus sensory loss on the medial hand. The other nerves don’t match that distribution: the median nerve covers lateral 3.5 digits, the radial nerve supplies the dorsolateral hand, and the axillary nerve is a shoulder nerve.

The ulnar nerve is involved. It supplies most of the intrinsic hand muscles (especially the interossei and the medial two lumbricals) and provides sensation to the medial aspect of the hand (including the little finger and the medial half of the ring finger). When this nerve is injured, you get weakness in the intrinsic hand muscles plus sensory loss on the medial hand. The other nerves don’t match that distribution: the median nerve covers lateral 3.5 digits, the radial nerve supplies the dorsolateral hand, and the axillary nerve is a shoulder nerve.