Final answer:
The most commonly involved ligaments in ankle sprains are the anterior talofibular and calcaneofibular ligaments, both of which are located on the lateral side of the ankle and help stabilize it against excessive inversion.
Step-by-step explanation:
Ankle Joint Ligaments and Injuries
The ankle is the most frequently injured joint in the body, typically from an inversion ankle sprain, where the anterior talofibular ligament is the most commonly involved ligament. This ligament is an intrinsic component located on the lateral side of the ankle joint, between the talus bone and the lateral malleolus of the fibula. It plays a crucial role in supporting the talus at the talocrural joint and resists excess inversion of the foot, which is when the sole of the foot turns inwards. Following the anterior talofibular ligament in frequency of injury is the calcaneofibular ligament, also located on the lateral side of the ankle between the calcaneus bone and fibula. Together with the anterior talofibular ligament, it constitutes the main support for the lateral ankle, stabilizing it against abnormal movements, and restricting excessive inversion that could lead to sprains.
Inversion injuries can be quite severe, potentially leading to ruptures of these lateral ligaments and even to fractures of the distal fibula. Proper understanding and diagnosis of the involvement of these ligaments are critical for treatment and rehabilitation of ankle sprains. The ligaments on the medial side, especially the deltoid ligament, provide resistance to eversion of the foot but are less frequently injured compared to their lateral counterparts.