Explanation:
The anterior talofibular ligament (ATFL) is the most commonly injured ligament in ankle sprains. It primarily resists anterior translation of the talus and inversion when the ankle is plantarflexed. Due to its orientation and biomechanical function, it is the weakest of the lateral ankle ligaments. Injuries typically occur during inversion injuries while the foot is plantarflexed. Damage to the ATFL leads to mechanical instability and recurrent sprains. Clinical tests such as the anterior drawer test help evaluate its integrity. Reference: Broström L. "Sprained Ankles: Anatomic Lesions in Recent Sprains." Acta Chirurgica Scandinavica, 1964.