Injury to the medial collateral ligament in the knee is extremely common in young athletes, especially those who ski or play hockey or football. While most people recover from a collateral ligament injury with non-surgical treatment that includes rest, ice, bracing, elevation, compression stockings, crutches, and physical therapy, some require surgery. Following surgery, the patient is kept off of the knee for at least three weeks in a long-hinged brace that allows only 30- to 90-degree motion. Three weeks later, the patient often can begin to use the full range of motion and place as much weight on the knee as pain allows. Six weeks after surgery (or, if no surgery is necessary, as soon as pain subsides), physical therapy will begin in the form of progressive exercises and stretches designed to restore strength and flexibility in the knee and the muscles supporting the knee as well as prevent reinjury. Some of these exercises may include swimming, cycling on a stationary bike, quad setting, heel propping, heel sliding, straight leg raises, partial squats, and wall slides. Brace-wearing is gradually weaned, and the return to sports following a medial collateral ligament injury is a slow process—although most people who complete treatment are able to return to their pre-injury functional abilities.