Injury Patterns by Body Mass Index in US High School Athletes

Background: There are over 7 million US high school athletes and one-third are overweight or obese. Our objective was to examine injury patterns by body mass index (BMI) in high school athletes. Methods: Certified athletic trainers (ATCs) at 100 nationally representative US high schools submitted exposure and injury information during the 2005 to 08 school years via High School RIO (Reporting Information Online). We retrospectively categorized injured athletes as underweight (<= 15th percentile), normal weight (15th-85th percentile), overweight (85th-95th percentile), or obese (>= 95th percentile). Results: ATCs reported 13,881 injuries during 5,627,921 athlete-exposures (2.47 injuries per 1000 athlete-exposures). Nearly two-thirds (61.4%) of injured high school athletes were normal weight. The prevalence of overweight and obesity was highest among injured football athletes (54.4%). Compared with normal weight athletes, obese athletes sustained a larger proportion of knee injuries (Injury Proportion Ratio [IPR] = 1.27, 95% CI: 1.14 to 1.42) and their injuries were more likely to have resulted from contact with another person (IPR = 1.31, 95% CI: 1.26 to 1.37). Compared with normal weight athletes, underweight athletes sustained a larger proportion of fractures (IPR = 1.45, 95% CI: 1.10 to 1.92) and a larger proportion of injuries resulting from illegal activity (IPR = 1.59, 95% CI: 1.03 to 2.46). Conclusions: Injury patterns differ by BMI. BMI-targeted preventive interventions should be developed to help decrease sports injury rates.