The American Journal of Orthopedics reports that up to 39 percent of college football players experience annual foot or ankle injuries. In high school athletics across the United States, it is estimated that 24 percent of all ankle sprains are in high school football players. Lateral ankle sprains are the most common football injury that affects the ankle and foot. A sprain is a tear or stretch in a ligament, a tissue that connects two or more joints and helps the joints move. An ankle sprain involves one or more ligaments. The injury may happen after twisting an ankle, making a hard cut, falling to the ground, or overusing a ligament. Those with an ankle sprain may feel a tear or pop in the joint during the injury. An ankle sprain from football can be mild, moderate, or severe. A severe sprain involves a complete ligament tear, rendering the joint nonfunctional and often causing severe pain. Moderate sprains involve partially torn ligaments and can leave the joint unstable. A mild sprain, on the other hand, will stretch the ligament but leave it intact.