What is the primary action of the lateral ligament of the ankle?

The lateral ligament of the ankle primarily functions to resist over-inversion of the foot. This ligamentous complex, which includes the anterior talofibular ligament, the calcaneofibular ligament, and the posterior talofibular ligament, provides critical support and stabilization to the lateral aspect of the ankle joint.

Injury to these ligaments often occurs during activities involving sudden changes in direction, which can cause the foot to invert excessively. The role of the lateral ligaments is crucial in preventing this inversion, thereby protecting the ankle from sprains and other injuries related to instability.

While other options discuss resisting eversion, maintaining stability during dorsiflexion, or supporting the arch of the foot, those actions are more aligned with different ligamentous structures or functions unrelated to the primary action of the lateral ligaments. The lateral ligaments are specifically adapted to counteract the forces that lead to excessive inversion, making them essential for ankle stability in various weight-bearing activities.