The Anterior Cruciate Ligament (ACL) limits rotation and the forward motion of the tibia. It crosses from the back of the femur to the front of the tibia. It is one of the four major ligaments that connect and stabilize the knee joint. ACL conditions are the most frequent knee injuries to occur during athletic activities such as skiing, soccer and football. ACL injuries are one of the most common knee conditions especially in women athletes. After an ACL injury the knee can easily buckle as the tibia shifts forward. In active people most ACL injuries either heal on their own or, in more severe cases, are successfully treated surgically by reconstructing the ligament. Immediately following surgery, knee immobilization or limited mobilization is usually indicated and a range of motion (ROM) knee brace prescribed. As healing progresses, a knee support or brace helps stabilize the knee joint and can also help prevent further injury or re-injury.