What is the most common ligament sprained on the lateral side of the ankle?

The anterior talofibular ligament is the most commonly sprained ligament on the lateral side of the ankle due to its anatomical position and function. This ligament connects the fibula to the talus and plays a crucial role in stabilizing the ankle during movements, particularly when the foot is in a plantarflexed position, such as during activities like running, jumping, or walking on uneven surfaces.

When the ankle is subjected to excessive inversion, the anterior talofibular ligament is typically the first to be impacted, making it susceptible to sprains. This is commonly seen in sports injuries and can result in pain, swelling, and instability in the ankle. Understanding the role of the anterior talofibular ligament helps identify why it is the most frequent site of sprain, emphasizing its importance in maintaining lateral ankle stability.

The other ligaments mentioned, while they also contribute to ankle stability, are either less commonly injured in lateral ankle sprains or are situated in a location where they do not experience the same level of stress during typical ankle injuries.