## **Core Concept**
The deep peroneal nerve, also known as the anterior tibial nerve, is a branch of the common peroneal nerve. It provides motor innervation to the muscles of the anterior compartment of the leg and sensory innervation to specific areas of the foot. The nerve plays a crucial role in controlling movements such as dorsiflexion of the foot and toes.

## **Why the Correct Answer is Right**
The deep peroneal nerve provides sensory innervation to the **first web space** of the foot, which is the area between the first and second toes. This is a key clinical landmark for assessing the function of the deep peroneal nerve. The sensory innervation is primarily mediated through the terminal branches of the deep peroneal nerve.

## **Why Each Wrong Option is Incorrect**
- **Option A:** The medial aspect of the leg is innervated by the saphenous nerve, a branch of the femoral nerve. Therefore, option A is incorrect.
- **Option B:** The lateral aspect of the leg is typically innervated by the superficial peroneal nerve, another branch of the common peroneal nerve. Thus, option B is incorrect.
- **Option C:** While the correct answer is related to the foot, without specific details on option C, we focus on the fact that the first web space is the correct area for deep peroneal nerve sensory innervation.

## **Clinical Pearl / High-Yield Fact**
A key clinical correlation is that damage to the deep peroneal nerve can result in **foot drop**, characterized by the inability to dorsiflex the foot. Additionally, patients may experience sensory loss in the first web space of the foot. This condition can significantly impact mobility and balance.

## **Correct Answer:** D. First web space.