According to a study a strain on the brain, and not the muscles, is what plays a major role in causing ACL knee injuries.
Suggesting a shift from performance-based to prevention-based athletic training programs, research have shown that training the brain may be just as effective as training the muscles in preventing ACL knee injuries.
The anterior cruciate ligament (ACL) is one of the four major ligaments of the knee, and ACL injuries pose a rising public health problem as well as an economic strain on the medical system.
University of Michigan researchers studying ACL injuries had subjects perform one-legged squats to fatigue, and then tested the reactions to various jumping and movement commands.
They found that both legs, not just the fatigued leg, showed equally dangerous and potentially injurious responses, said Scott McLean, assistant professor with the U-M School of Kinesiology.
The fatigued subjects showed significant potentially harmful changes in lower body movements that, when preformed improperly, can cause ACL tears.
"These findings suggest that training the central control process, the brain and reflexive responses, may be necessary to counter the fatigue induced ACL injury risk," said McLean.
He said that most research and prevention of ACL injuries focuses below the waist in a controlled lab setting.
However, the new approach is attempting to untangle the brain's role in movements in a random, realistic and complex sports environments.
McLean said that the findings could have big implications for training programs.
Mental imagery or virtual reality technology can immerse athletes to very complex athletic scenarios, thus teaching rapid decision-making.
It might also be possible to train "hard wired" spinal control mechanisms to combat fatigue fallout.
The research has suggested that training the brain to respond to unexpected stimuli, thus sharpening their anticipatory skills when faced with unexpected scenarios, may be more beneficial than performing rote training exercises in a controlled lab setting, which is much less random than a true competitive scenario.
The study, titled 'Fatigue Induced ACL Injury Risk Stems from a Degradation in Central Control', will appear in Medicine and Science in Sports and Exercise.