According to the results made available online in April in the British Journal of Sports Medicine, young women whose ACLs had popped exhibited more trunk sway than the men or the uninjured women.
Again, injury prevention leads to performance enhancement. Players whose upper bodies sway when they change directions do so more slowly. Learning to “meet your momentum” (Lee Taft) and eliminate this sway is a key aspect of agility, acceleration and deceleration (video below depicts the “Ice Skater Drill” and illustrates an athlete who controls his upper body on each landing; ignore the first jump).
Therefore, according to Dr. Hewett’s study, training to prevent injuries and to enhance performance require the same thing.
“Our research suggests that the issue in injured female athletes,” Hewett says, “is a lack of high-level ability to control deceleration and acceleration at the center of their mass in three-dimensional space.”
Hewett provides a very basic, very generic test that coaches, parents and players can use to judge their susceptibility to an ACL injury:
- Set up a foot-high box.
- Have the athlete stand on it and hop down lightly, then immediately leap straight up as high as she can and land back on the ground.
- Watch closely or videotape her.
Did her knees move toward each other as she landed the first time? Did they seem to collapse inward as she exploded back up? Did she lean forward or to the side as she landed back on the ground? Those are each probable hallmarks of high risk, Hewett says.
Once susceptibility to injury is measured, players, coaches and parents need to be proactive. Developing core stability does not mean doing crunches. Instead, players need to develop core stability through movement – they need to control their body weight over their base of support. Also, they need to be able to control their body weight in reactive situations, not just static (expected) situations, like a typical single-leg balance test(example below of a static single-leg reach test).