ACL Injury: Contact vs. Non-Contact

An ACL injury happens frequently in sports such as soccer, gymnastics, skiing, football, etc. And female athletes may be 4-6 times more prone to an injury than male counterparts. Even though it happens more often in contact sports, about 75% 0f the injury happens without involving a contact with another player. It has gotten more attention because of the seriousness of the injury and many research articles regarding the issue have been published. As a result, we know more about how the injury happens, what factors are involved, who may be more prone, how to prevent it, etc.

Contact ACL Injury

A common mechanism of contact ACL injury involves falling down while being tackled in the knee or lower leg, which forces the knee into valgus motion (knee bending in). The foot usually is planted on the ground by a tackling athlete and it becomes difficult to control his lower legs and the body. It can also happen when an athlete is tackled in the front of the leg causing the knee to hyperextend.



Non-Contact ACL Injury

A non-contact ACL injury occurs more frequently than contact ACL injury. It is common in soccer, basketball, gymnastics, skiing, etc. Athletes may sustain this injury when they are try to stop and make a quick change in direction leaving the foot planted on the ground while the body is being twisted. Another mechanism of injury is landing and hyperextending the knee. It also happens when the knee collapses into valgus on landing. The athlete usually does not have a good control of the body when he/she gets hurt.



A contact ACL injury is harder to predict, however, a non-contact ACL injury can be prevented by implementing balance training, proprioception training, strengthening exercises, neuromuscular program, etc.