The little toe dermatome most commonly corresponds to which spinal segment?

• A. L4
• B. L5
• C. S1
• D. S2

Answer: (C)

Dermatomes map the body’s surface to specific spinal segments, so the sensation on a given toe or area reflects the spinal roots that supply that region. The little toe sits on the lateral side of the foot, and its cutaneous sensation is carried mainly by the S1 dermatome (with some contribution from S2). That makes S1 the best match for the little toe.

In contrast, L4 covers the medial leg and much of the medial foot, including the big toe region; L5 covers the dorsum of the foot and the first web space; and S2 tends to map to the posterior thigh and lower leg. Clinically, loss of sensation in the little toe points toward S1 (and ankle reflexes, like the Achilles, can be affected with S1 involvement).