Identification of the retrotalar pulley of the Flexor Hallucis Longus tendon.

Functional Hallux Limitus is the expression of the gliding restraint of the Flexor Hallucis Longus (Fhl) tendon, resulting in several painful syndromes. This impingement is located along the tract of the Fhl tendon at the level of its retrotalar tunnel sealed posteriorly by a fibrous pulley. This pulley, although poorly anatomically characterized, has been arthroscopically proven that its presence or resection plays a pivotal clinical role in the biomechanics of the lower leg, being the main restraint to the physiological movement of the Fhl tendon.