The posterior tibial nerve is a major peripheral nerve in the lower extremity, specifically located in the leg. It is one of the branches of the sciatic nerve, which is the largest nerve in the body. The posterior tibial nerve arises from the spinal nerves in the lower back, specifically from the fourth and fifth lumbar segments and the first, second, and third sacral segments of the spinal cord.
This nerve passes through several regions, such as the thigh and the back of the knee, before reaching the leg and foot. It primarily innervates the posterior compartment of the leg, providing motor and sensory functions.
Motor function includes controlling the muscles responsible for foot and toe movements, particularly the muscles that control inversion and plantar flexion of the foot. Sensory function involves carrying sensory information from the back of the leg and sole of the foot to the brain, providing sensation to these areas.
The posterior tibial nerve plays a crucial role in maintaining proper foot and leg movements, balance, and sensation. It is susceptible to irritation and compression, which can lead to various conditions and symptoms such as pain, numbness, tingling, weakness, and difficulty in walking or balancing. Medical professionals may perform diagnostic tests, such as nerve conduction studies, to assess the function and integrity of the posterior tibial nerve when evaluating potential nerve injuries or disorders related to this nerve.
