One can train the brain too, apart from just the muscles, to avert certain knee injuries, American researchers have found.

One common injury is to the ACL, or anterior cruciate ligament, which is one of the four major ligaments of the knee.

When the researchers from the University of Michigan had subjects perform one-legged squats until they were tired, then tested their reactions to various jumping and movement commands, they found that both legs were equally at risk of ACL injury, ScienceDaily reported.

There were significant potentially harmful changes in lower body movements, said Scott McLean, assistant professor of the university's School of Kinesiology.

He suggested that training the central control process - the brain and reflexive responses - might counter the fatigue-induced ACL injury risk.

Most research on the prevention of ACL injuries have focused on the area below the waist in a controlled lab setting.

However, Prof McLean saw wider implications of his team's brain-focused research. Using virtual reality, athletes could be trained to make quick decisions in complex situations. It might also be possible to 'hard wire" spinal control mechanisms to combat fatigue fallout.

Another related study by Prof McLean's group found that men and women showed significant changes in lower limb mechanics during unanticipated single leg landings. The findings also pointed to the brain's role.

In the exercises, the subjects' legs were worked till they were tired. While both men and women suffered ACL injuries, women were two to eight times more likely to tear this ligament than men.

The new research pointed to the possibility of training the brain to respond to unexpected stimuli, thus sharpening one's anticipatory skills when faced with unexpected scenarios.

This may be more beneficial than the predictable rote training exercises.

Hence, exposing athletes to more scenarios and training the brain to respond more rapidly can decrease the likelihood of a dangerous response.

Prof McLean used the analogy of a seasoned motorist and a novice, both driving a manual-gear car. The novice 'might make a slow or even incorrect decision' in a sudden stall, he said.

This article was first published in Mind Your Body, The Straits Times.