Which ligament is commonly involved in a lateral ankle sprain?

The anterior talo-fibular ligament is commonly involved in a lateral ankle sprain due to its anatomical location and function. This ligament connects the talus bone to the fibula and is the most frequently injured ligament when the ankle is subjected to an inversion force, which is the typical mechanism of injury in lateral sprains. During an inversion injury, the foot rolls inward, placing stress on this ligament, leading to pain and instability.

The other ligaments mentioned do not typically sustain injury in lateral sprains. The spring ligament, for instance, is part of the medial support structure of the foot and is not involved in lateral ankle stability. The inferior talo-calcaneal ligament, located more medially and vertically, also does not play a significant role in lateral ankle stability. Similarly, the deltoid ligament is a complex of ligaments on the medial side of the ankle and is more often associated with injuries resulting from eversion rather than inversion.

Understanding the specific roles of these ligaments and their anatomical positions helps clarify why the anterior talo-fibular ligament is primarily implicated in lateral ankle sprains.