ACL tear is one of the most common knee injuries. The ACL (anterior cruciate ligament), along with three other ligaments, connects the femur to the tibia. Individuals who play sports that are likely to damage the knee – such as football, basketball, soccer or skiing – are at greatest risk for injuring their ACL. Only about 30 percent of ACL injuries result from direct contact with another player or object. The rest occur when the athlete decelerates while cutting, pivoting or sidestepping; lands awkwardly; or plays recklessly. Symptoms of an ACL injury may include pain, swelling, and instability immediately after the injury, followed hours later by heightened pain and swelling, limited motion, and an inability to walk comfortably. To minimize the occurrence of an ACL tear, it is important to stay fit year-round.