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

• A. L5
• B. L4
• C. L3
• D. S1

Answer: (B)

The great toe map follows the fourth lumbar segment. In most standard dermatomal diagrams, the medial aspect of the foot and the region including the big toe are supplied by the L4 dermatome, which also aligns with the medial malleolus and the medial part of the sole. That makes sensation on the hallux a typical indicator of L4 innervation. The other segments don’t fit as well: L5 usually covers the dorsum of the foot and the first web space between the toes, S1 covers the lateral aspect of the foot and the sole, and a higher segment like L3 would involve the anterior thigh region rather than the foot. Keep in mind there is some variation between individuals and different maps, but L4 is the most consistent match for the great toe in common practice.