Does sports specialization lead to increased injury rates in youth?

Kocher sports specialization and injury risk Notes blog

Sports specialization has become increasingly common amongst young athletes, as have the rates of both orthopedic injuries and major injuries such as ACL tears. These concerning trends are not coincidental, reports Mininder Kocher, MD, M.P.H, an orthopedic surgeon and the associate director of Boston Children’s Sports Medicine Division, in a recent presentation to the American Academy of Orthopedic Surgeons (AAOS).

A comprehensive assessment

Kocher’s study investigates the link between youth sports specialization and increased injury risk, utilizing 1997-2004 data from the Growing Up Today Study (GUTS) cohort study — a prospective assessment of youth throughout the United States that was done out of Brigham and Women’s Hospital, encompassing almost 12,000 youth and their injury history completed by the mothers, who are registered nurses.

In his study, Kocher looked at overuse injuries such as stress fractures and tendinitis, as well as acute injuries like ACL tears, and defined sports specialization as engaging in one specific sport in the fall, winter and spring.

Specialization versus activity level

One of the important questions Kocher sought to answer was whether an increase in injury risk was a direct result of specialization, or due to a greater volume of physical activity. “Prior studies looking at sports specialization haven’t been able to separate the two because they haven’t measured the hours per week of the vigorous activity,” Kocher explains. “This database really gave us the opportunity to delve deeper.”

The results were separated by both specific sports and gender. “In females, once we adjusted for the total hours per week of vigorous activity, the individual sports risks went away,” says Kocher. But for boys, the results showed an increased injury risk for individuals who specialized in baseball or gymnastics. Kocher believes that these findings are due to the repetitive throwing motion used in baseball — especially for young pitchers — and the repetitive impact that occurs during gymnastics.

This is the first study to suggest that the total hours per week of vigorous activity may actually be more of a factor than sports specialization.

A cultural shift

The recent shift in youth sports culture has led to younger kids playing at greater competitive levels and focusing on a single sport. “Many kids were specializing in a single sport in high school, but now it’s clearly established in middle school,” Kocher says. “We’re even starting to see it into grade school, where kids are playing sports like soccer all year-round.” It represents a paradigm shift, where many parents believe that focusing their child on a single sport will help make them more successful — but this theory isn’t supported by current research.

“There aren’t really a lot of data to suggest that early specialization results in better athletes,” explains Kocher. “Actually, there are a fair number of data looking at college and professional athletes showing that those who played multiple sports were more likely to end up playing sports in college and at professional levels. The ones who focused on a single sport were more likely to burn out or to get injured.”

In fact, by age 14, about 70 percent of children are dropping out of sports. This could be for several reasons; they are not able to make the team, they’ve developed other interests or they’re just burned out after focusing on one sport for so long. “For us, that is a really concerning statistic,” says Kocher.” We want to keep kids active. Being involved in sports is better for their physical and psychosocial health.”

“Our children are getting very dichotomized,” says Kocher. “We have this group of kids who aren’t active enough and are either obese or at risk of obesity. But on the other hand, we have this group of youth athletes who are overdoing it at high rates physically and are at risk for burnout psychologically.”

So how do you balance a child’s activity between too much vigorous activity and not enough activity?

Helping your patients find balance

Although there isn’t a definitive answer to this problem, Kocher does have recommendations on appropriate activity levels for youth. He is currently doing further analysis to find a threshold number of hours for each age group that keeps kids active without overdoing it.

“Our current recommendation is that the number of hours of vigorous sports activity per week should probably correlate to their age. This means that if the child is 12 years old, we recommend 12 or less hours of vigorous sports during the week.”

These recommended hours aren’t limited to all activity — just vigorous sports activity such as organized practices or games. Ultimately, the goal is to determine how we can better protect children and adolescents while also encouraging them to remain active. We know that sports can benefit kids both physically and psychosocially, but we’re now looking to refine the ways in which we encourage kids to participate.

Learn more about Boston Children’s Sports Medicine Division.