During upper-extremity wound assessment, which nerve is tested by sensation at the first dorsal web space?

During upper-extremity wound assessment, which nerve is tested by sensation at the first dorsal web space?

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

Answer: (B)

Testing sensation in the first dorsal web space targets the area supplied by the superficial branch of the radial nerve, which provides cutaneous sensation to the dorsoradial hand and the web space between the thumb and index finger. In upper-extremity wound assessment, this makes it a reliable bedside check for radial nerve integrity: if sensation in this web space is preserved, the radial nerve branch being tested is likely intact; if it’s diminished or lost, it points to radial nerve injury proximal to that sensory branch. The other nerves don’t innervate this spot—median nerve covers the palmar surfaces of the lateral digits, ulnar nerve the medial hand and little finger, and axillary nerve sensation is over the shoulder area—so this web space specifically indicates radial nerve function.

Testing sensation in the first dorsal web space targets the area supplied by the superficial branch of the radial nerve, which provides cutaneous sensation to the dorsoradial hand and the web space between the thumb and index finger. In upper-extremity wound assessment, this makes it a reliable bedside check for radial nerve integrity: if sensation in this web space is preserved, the radial nerve branch being tested is likely intact; if it’s diminished or lost, it points to radial nerve injury proximal to that sensory branch. The other nerves don’t innervate this spot—median nerve covers the palmar surfaces of the lateral digits, ulnar nerve the medial hand and little finger, and axillary nerve sensation is over the shoulder area—so this web space specifically indicates radial nerve function.