[TA] arises from the tibial nerve in the popliteal space, passes down the calf between the two heads of the gastrocnemius and unites in the middle of the leg with the communicating branch of the common peroneal to form the sural nerve, distributed to the skin of the distal and lateral surfaces of the leg and ankle. SYN: nervus cutaneus surae medialis [TA], popliteal communicating nerve, tibial communicating nerve.