FRIDAY, March 18 (HealthDay News) -- Ankle and knee braces may sound like a wise investment for teen athletes looking to avoid injuries, but new research suggests the braces cause more problems than they prevent.

North Carolina teens who wore ankle and knee braces were 1.6 to 1.7 times more likely to become injured than their fellow athletes, according to new findings released this week. Of the third most commonly used types of lower-extremity braces, only the kneepad turned out to be beneficial.

The researchers behind the study aren't saying all teens should stop wearing the knee and ankle braces entirely. But young athletes should make sure they consult with experts about wearing them, especially if they're already hurt, said study co-author Jingzhen Yang, an assistant professor of behavioral health at the University of Iowa.

"If the athletes haven't fully recovered, we don't recommend that they just put on a brace and go back to play," Yang said.

Athletic trainers have spent years debating the value of ankle and knee braces, which are a common sight on football fields and basketball courts. In the new study, researchers looked at the records of students who took part in 12 organized sports in 100 North Carolina high schools from 1996-1999. Combined, the students played sports for 19,728 seasons.

The findings appear in the March 15 issue of the American Journal of Epidemiology.

Students who wore knee braces -- also known as anterior cruciate ligament (ACL) braces -- were 1.61 times more likely to suffer knee injuries as those who didn't, and the ankle injury rate was 1.74 times higher for those who wore ankle braces as for those who didn't.

It's possible that knee braces contributed to ankle injuries and ankle braces to knee injuries, Yang said. Researchers hope to investigate that theory further.

The researchers also speculated that the knee and ankle braces could have slipped during use. One more possibility is that athletes wearing them "may play more aggressively," Yang said. "And they could have had an injury before, and weren't fully recovered."

Kneepads, by contrast, reduced knee injuries by 56 percent. They're so effective at absorbing impact that baseball and softball teams should consider making them mandatory, Yang said. Athletes in the study wore the braces voluntarily, he pointed out.

Tab Blackburn, executive director of the Tulane Institute of Sports Medicine, said he's not surprised by the findings, considering that research hasn't proven the effectiveness of either ankle or knee braces.

He suggests that teen athletes protect their ankles by using lace-up braces (also known as taping) and wearing high-topped shoes. "It's so easy for parents," he said.

As for knees, he noted that studies haven't shown knee braces to be effective, even if they cost hundreds of dollars. Instead of buying a brace, he said, "get your child's leg muscles as strong as possible and then make sure they are in good cardiovascular conditioning."

More information

Learn more about knee braces from the American Academy of Family Physicians.