to an athlete, aching young

specialization and year-round play are putting active kids at increased risk of crippling injury 
cody walker of columbus, ga., and japan's catcher ryota koike play in the little league world series championship baseball game.considering the fact that 1 out of 6 youngsters in the u.s. is overweight, you'd think that any increase in physical activity for kids has got to be a good thing. but that isn't necessarily so. it's true that the earlier in life you make running, jumping, swimming and other physical activities a regular part of your daily routine, the healthier you'll be--provided that you keep it up as an adult. but the enormous boom over the past few years in soccer, gymnastics and other highly competitive sports for children has a dark side as well: an epidemic of sports injuries that go well beyond the bruises, scrapes and occasional broken bones parents might expect.

in some cases, those injuries can lead to crippling arthritis or require extensive surgery to repair. it's no longer unheard of, to name just one example, for a 10-year-old baseball pitcher to need a tendon transplant for an ailing elbow--an operation that used to be restricted almost entirely to major league baseball players. and orthopedic surgeons report they are under increasing pressure to offer ever more experimental surgery for younger athletes.

although sports injuries are a danger at any age, youngsters in their preteen and early teen years are particularly vulnerable, especially to vigorous, repetitive movement, because of the way their bones grow. instead of expanding all along their length, as you might assume, young bones generate new tissue at so-called growth plates located near the ends of most bones. "the growth plate is actually at its most vulnerable in the year before it closes," says dr. jon divine, medical director of the sports medicine biodynamics center at cincinnati children's hospital in ohio. reason: a protective band of tissue that supports the growth plate starts to break down at puberty so that bone can completely ossify in preparation for adulthood. without that protective band, the plate is especially susceptible to being unnaturally compressed or even pulled apart. parents are often shocked to discover that overuse injuries may require six months or more to heal properly.

specializing in one sport and playing it year round is an obvious way to court trouble. but young athletes can also be tripped up by playing different sports that put stress on the same parts of their body over and over again. for example, swimming, water polo and volleyball put a great deal of strain on the shoulders, so athletes wouldn't really give themselves a rest by switching among those sports. for the same reason, softball pitchers shouldn't swim competitively in the off-season or play football. they would be better off doing something dissimilar like bicycling, which uses different sets of muscles.

each sport comes with characteristic dangers. whereas volleyball players and swimmers are prone to overuse injuries of the shoulder, basketball and soccer players often have trouble in one or both of the knees. divers, cheerleaders, gymnasts and football linemen, meanwhile, are susceptible to stress fractures of the lower back. indeed, lower-back pain is normally uncommon in adolescents. if it shows up, parents should schedule an immediate visit to a doctor.