The peroneal nerve is a branch of the sciatic nerve that runs down the leg. It is responsible for controlling the muscles that lift the foot and toes, as well as providing sensation to parts of the lower leg and the top of the foot. Injury to the peroneal nerve can lead to conditions such as foot drop, where a person has difficulty lifting the front part of the foot. This can affect walking and balance, making it important to seek medical attention if symptoms arise.