The Effect of Single Sport Specialization in Youth Sports: A Prospective Cohort Study

OBJECTIVES: Large numbers of youth participate in both team and individual sports. In recent years, sports specialization has become increasingly popularized in younger athletes. There is concern that early sports specialization increases the risk of overuse injuries in youth athletes. The purpose of this investigation was to determine the prevalence of sport specialization in youth athletes, and prospectively examine whether specialization correlates with an increased incidence of athletic injury. METHODS: 895 high school freshman athletes were enrolled starting in 2016, with the intent of following them through the completion of their high school careers. They were recruited from 3 high schools within the same school district. Sports specialization was defined as participating in a single sport in excess of 6 months of the year at the exclusion of other sports. Athletes’ demographic information, sport commitment and injury history were collected through a sports specialization and injury survey. The same athletes were queried again at the conclusion of each season to collect injury information. Athletic training records were used to corroborate, in order to ensure capture of all injuries reported to health care personnel. RESULTS: Of the 895 athletes, 216 (24.1%) reported sport specialization at some point during their high school sports careers. Specialized athletes were exposed to significantly more sports activity (8.41 hours/week vs 7.10 hours/week, p<0.00001 ). They were also much more likely (70.6% vs 25.1%, p< .00001) to compete on a club or travel team for their sport. Male athletes were more likely to specialize than females (27.0% vs 19.3%, p<0.0072). Baseball (12.1% of specialized athletes vs 4.9% of all athletes, p<0.000032) main sport athletes were the only athletes significantly more likely to report specialization. Specialized athletes were significantly more likely than their nonspecialized counterparts to report an injury (39.8% vs 33.2%, p< 0.0271). These athletes suffered from higher severity injuries, requiring more time to recover than their peers. (p<0.0483). Despite the higher propensity for injury in specialized athletes and greater tendency for specialization in males, female athletes were more likely to report injures (p<0.0053). The most common reported injuries were of the knee, ankle, and head (18.6%, 18.2%, 16.6% of all injuries respectively). Season ending injuries were also most commonly knee, ankle, and head injuries (48.5%, 15.2%, 12.1% respectively), with 30.3% of all reported season ending injuries being ACL tears. CONCLUSIONS: Specialized student athletes tend to have significantly more injuries than non-specialized athletes, as well as more severe injuries than non-specialized athletes. This is one of the largest and most comprehensive studies to date, evaluating the effect of sports specialization on the incidence of athletic injury in high school athletes.