Sprained ankle

A sprained ankle or twisted ankle as it is sometimes known is a common cause of ankle pain. A sprain is stretching and or tearing of ligaments (you sprain a ligament and strain a muscle). The most common is an inversion sprain (or lateral ligament sprain) where the ankle turns under so the sole of the foot faces inwards, damaging the ligaments on the outside of the ankle.

A medial ligament sprain is rare but can occur particularly with a fracture. This happens when the ankle rolls the other way, so the sole of the foot faces outwards, damaging the ligaments on the inside of the ankle.

The most common damage sustained in a sprained ankle is to the anterior talo-fibula ligament shown towards the front of the image opposite. This ligament, as the name suggests, connects the talus (ankle bone) with the fibula (smaller of the two bones in the lower leg). If the sprain is severe there might also be damage to the calcaneo-fibula ligament (connects the heel bone to the fibula) which is further back towards the heel. This ligament only becomes injured in more severe injuries due to its increased strength and laxity whilst the toes are pointed (a common position for injuries).

In addition to the ligament damage there may also be damage to tendons, bone and other joint tissues, which is why it is important to get a professional to diagnose your ankle sprain. Complete ruptures of the anterior talo-fibular, calcaneo-fibular and posterior talo-fibular ligaments results in dislocation of the ankle joint and is often associated with a fracture.