There are exercise programs that have been designed to prevent ACL tears. They involve strengthening and balance exercises, as well as training in jumping and landing techniques.

Going skiing? These exercises can prevent vacation-ending injuries. About 120,000 recreational skiers tear their ACL each year. Understanding how it happens can lower the risk.

But Mandelbaum also has spent nearly two decades studying how to prevent and reduce ACL injuries, a quest that began when he and other doctors saw a spike in knee injuries among female teenage ...