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BACKGROUND: Abrupt training stoppage can increase injury incidence and risk following return to sport. The rate of coronavirus disease 2019 (COVID-19) infections in the general population has resulted in the abrupt stoppage of high school education and sport. The objective of this study was to (1) compare injury incidence proportion (IP) and excess injury in high school athletes before and during the COVID-19 pandemic; and (2) stratify by identified gender. HYPOTHESIS: The COVID-19 academic year will demonstrate increased injury incidence, and injury incidence will be similar between genders. STUDY DESIGN: Ecological. LEVEL OF EVIDENCE: Level 2. METHODS: High schools (6 states; 176 high schools) were matched between prepandemic and pandemic years. Injury IP with 95% confidence interval (CI) was calculated. Interrupted time series models with robust errors were performed to assess the IP ratio and excess injury incidence between prepandemic and pandemic academic calendar years. RESULTS: A total of 98,487 athletes participated in high school sport in the prepandemic year and 72,521 athletes in the pandemic year; 15,477 injuries were reported in the prepandemic year compared with 14,057 injuries during the pandemic year. Injury IP (CI) was 15.7 (15.5-15.9) and 19.4 (19.1-19.7) for the prepandemic and pandemic years, respectively. Injury incidence ratio increased by 1.3 (1.2-1.5) between the prepandemic and pandemic years. Excess injuries were 1812 greater in the pandemic year compared with the prepandemic year. Female and male athlete incidence ratios were similar. CONCLUSION: Prolonged sport stoppage due to the COVID-19 pandemic resulted in increased injury incidence compared with the previous high school academic year. CLINICAL RELEVANCE: High school sports stakeholders should consider longer periods of ramp up for training in lieu of future sport stoppages compared with usual preseason training. These data may also have more generalizable implications to other abrupt sport and physical activity stoppage scenarios such as earthquakes and hurricanes.

Original publication




Journal article


Sports health

Publication Date



athlete, hamstring, knee, loading, sport