A high ankle sprain causes the foot to move outward (called "external rotation"), resulting in more discomfort on the ankle than a low ankle sprain. In certain cases, persons might injure both sets of ligaments, resulting in a combined injury. The talus (or ankle bone) moves closer toward the midline of the body when a high ankle sprain occurs. The ligaments are groups of tough bands connecting one bone to another and helping to maintain stability within the skeletal system. There are three major ligaments that connect your ankle to your heel bone (calcaneus). They are the anterior talofibular ligament, the posterior talofibular ligament, and the calcaneal tendon. When these ligaments are injured, they cause pain and instability of the ankle joint. A person who has sustained an unstable ankle injury may experience further damage due to repeated motions or changes in direction of the leg. Ankle sprains are common injuries that can happen to anyone playing sports or engaging in other activities where the ankle is subjected to stress. Ankles are a complex structure composed of several bones which function together as a unit so that weight bearing does not put excessive strain on any one part. Ankles are also stabilized by muscles and ligaments which must be healthy for proper function of the ankle. Ankle sprains can be classified as either acute or chronic.