The tibial nerve is a major nerve in the leg that branches from the sciatic nerve. It runs down the back of the leg and is responsible for controlling muscles in the calf and foot. This nerve also provides sensation to the skin on the sole of the foot and parts of the lower leg. In addition to motor and sensory functions, the tibial nerve plays a role in the plantar flexion of the foot, which is essential for walking, running, and standing on tiptoes. Damage to the tibial nerve can lead to weakness, pain, or numbness in the affected areas.