What nerve is primarily responsible for the sensory and motor function of the posterior leg and plantar foot?

• A. Peroneal nerve
• B. Tibial nerve
• C. Sural nerve
• D. Femoral nerve

Answer: (B)

The tibial nerve is primarily responsible for both the sensory and motor functions of the posterior leg and plantar foot. It is a branch of the sciatic nerve and travels down the posterior aspect of the leg. This nerve innervates the muscles located in the posterior compartment, which include the calf muscles (gastrocnemius and soleus) that are crucial for plantarflexion as well as other important muscles in the foot.

In addition to its motor function, the tibial nerve provides sensory innervation to the sole of the foot, allowing for the perception of touch and sensation. This dual role in regulating movement and sensation in the leg and foot makes the tibial nerve essential for activities such as walking and standing.

The other nerves listed have distinct roles that do not cover the posterior leg and the plantar surface adequately. For instance, the peroneal nerve (often referred to as the common fibular nerve) is more involved with the lateral compartment and anterior compartment of the leg, playing a role in dorsiflexion rather than plantarflexion. The sural nerve primarily provides sensory innervation to the posterior and lateral aspects of the leg but lacks motor function. The femoral nerve is primarily involved with the anterior thigh muscles and does not contribute