Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which nerve is responsible for sensation in the big toe?

1. Sural nerve

2. Fibular nerve

3. Femoral nerve

4. Tibial nerve

The correct answer is: Tibial nerve

The tibial nerve is responsible for sensation in the big toe because it innervates the plantar aspect of the foot, where the big toe is located. This nerve branches into the medial and lateral plantar nerves, which provide sensory innervation to the medial side of the foot, including the big toe area. The other nerves listed have different roles: the sural nerve primarily provides sensation to the posterior and lateral aspects of the leg and foot; the fibular nerve generally innervates the lateral compartment of the leg and provides sensation to the upper pole of the foot; and the femoral nerve primarily innervates the anterior thigh and has no direct role in the sensation of the big toe. Understanding the specific areas each nerve supplies helps clarify why the tibial nerve is the correct choice for sensory function in the big toe.