In the ankle region, the tendons of the lower leg are bound to the leg by thick, fibrous, strap-like bands called retinacula. These bands lie between the malleous (network of nerve tissue and muscle around the ankle) and the Achilles tendon, forming a sheath for the tendons passing beneath the foot. The retinacula work together and prevent the tendons from bowing and pulling away from the leg when their muscles contract. It is similar to the retinacula that wraps around the wrist.
