An ankle sprain is an extremely common injury, occurring approximately 25,000 times per day. When the ankle is subjected to abnormal movements, the ligaments can become torn or stretched, causing pain and swelling. Depending on the extent of the injury, strains can be mild, moderate, or severe. They are usually treated with protected weight bearing until pain and swelling decrease, and occasionally require physical therapy to return to athletics. If sprains keep recurring, surgery may be required to repair the ankle ligaments.