ACL Tears: A Preventable Epidemic?

ACL tears remain one of the most devastating injuries to strike young athletes. Although techniques for surgically reconstructing and rehabilitating ACL injuries have improved immeasurably, most athletes cannot return to high level sports until approximately five to six months after surgery. And there appears to be a correlation between ACL tears and eventual osteoarthritis. With significant ramifications for the individual and society, preventing ACL tears is a paramount concern.

With that in mind, the UI Sports Medicine invited Tim Hewett, PhD, C.S.C.S., to discuss his program for ACL injury prevention. Hewett, director of Sports Medicine at Cincinnati Children's Hospital, is one of the world's foremost authorities on ACL injury prevention. Although his primary focus is on ACL injury prevention, he noted that most participants realize a more immediate payoff: "I can improve their speed, vertical jump, and power."

Hewett presented his methodology and research to an audience of sports medicine professionals and a public seminar in December.

Evidence suggests ACL injury prevention programs reduce the rate of ACL tears in females (ACL tears predominantly affect girls) by 20 to 80 percent; it is not yet known whether these programs consistently reduce ACL injury rates in males. "You probably can't prevent all ACL tears," says Glenn Williams PhD, P.T., A.T.C., UI Sports Medicine Center research director and an expert in this field, "but that doesn't mean you shouldn't try."

Landing mechanics are a primary focus. Adolescent girls tend to land with their knees extended and internally rotated. They land with their foot outside of their base of support. Instead of keeping their lower extremities well aligned, girls absorb the forces from jumping by flexing their knees inward as opposed to a front-to-back direction.

Injury prevention begins with teaching girls to recognize this movement and giving them the tools to improve mechanics. The goal is to strengthen the muscles so that they land with their knees more flexed and lower extremities more aligned. In Hewett's program, the initial stages of a program may focus only on a squatting form before progressing to broad jumps and finally landing on two legs when jumping down from a small box. Increasingly more complex activities are added until the participants simulate landing from a vertical jump.

"Most girls tend to have one dominant leg that they like to land on," Hewett explains. This is why nearly all ACL injury prevention programs also include targeted strengthening of the lower extremities and single leg jumping tasks to correct these muscle imbalances. Well-rounded prevention programs typically include strengthening of the trunk stabilizers (abdominals and gluteal muscles) as well.

Because of the emphasis on muscle strengthening, nearly all (female or male) athletes see a noteworthy increase in their speed and vertical jump height, which should improve athletic performance.

If you or your team is interested in an ACL Injury Prevention/ Performance Enhancement program with UI Sports Medicine, please call the clinic at 319-384-7070.