Fitness | What knees need

Recent studies have shined a spotlight on injuries — especially to the knee — among preteen and teenage female soccer players. Soccer is not an inherently dangerous sport, but it is popular and attracts young athletes whose bodies may not be prepared enough for the rigors that competition demands.

Health researchers are studying the numbers and looking for patterns, while doctors and physical therapists urge coaches to spend time on preparing the lower body as well as the game plan.

One of the latest studies was co-authored by Harborview Injury Prevention & Research Center and the University of Washington Medical Center. It found that nearly one-third of 103 girls ages 11 to 14 who responded to a questionnaire reported soccer-related injuries during a recent season. And nearly 45 percent said they had been injured sometime since they began playing.

Dr. John O'Kane, associate professor of orthopedics and sports medicine at the UW Medical School, co-authored the study and implores parents and coaches not to push their young athletes too hard.

"Coaches may not be aware that preteens and young teens should not be trained as if they were women and that they are susceptible to overuse injuries," he says. "And often these young athletes are on other teams and different sports. So they may have multiple coaches training them like their sport is the only sport the girl is playing."

O'Kane urges parents to ask coaches about spending time on preventive exercises. Just 10 minutes spent on strength, flexibility and biomechanics, while probably not enough, can help, he says.

"Waiting too long to make this a habit is like waiting until you're about to have a car crash to click your seat belt," he says.

A recent study published in the Journal of Bone & Joint Surgery contends that muscular changes that occur when female athletes near adolescence reduce the control they have over their knee joints. And it goes beyond soccer. Most competitive sports require sudden stops or twists, which can sometimes be more than the anterior cruciate ligament (ACL) can handle.

One theory is that girls' growth and bone length do not seem to come with increased strength and power needed for control of the knee.

Because of the knee's complex architecture, diagnosis can be tricky. Err on the side of safety, and have a professional check it out if pain persists. And it's a good idea to get a wide range of exercise, not just what is specific to your favored sport.

The Harborview-UW study also found:

• Girls spent an average of 5.6 hours per week playing soccer, one hour of which was in games.

• Most reported playing year-round, with most playing seven or more years.

• More than 40 percent of those reporting injuries said they lost more than 10 days of soccer due to injury.

• Most of the injured players sought medical care for their injuries, and 30 percent received physical therapy.

O'Kane and co-researcher Dr. Melissa Schiff, of the Harborview Injury Prevention and Research Center, are pursuing a more detailed study of soccer injuries in 12- to 15-year-old girls over a one-year period. The study is evaluating recreational as well as premier soccer players to determine rates of injury. Schiff is also assessing muscle strength and jumping patterns as potential risk factors for injury.