A Winter World Cup Interrupted Season Increased Injury Rates in First Division European Soccer Leagues

Background For the first time in its history, the FIFA World Cup was held in the winter instead of its traditional summer time slot. This time slot interrupted European domestic leagues that run through the winter and forced them to congest matches, schedule a month-long break, and prolong their season. The purpose of this study was to compare the injury rates between a normal uninterrupted season and the 2022/2023 World Cup interrupted season. We hypothesized that the 2022/2023 season would have an increase in muscle injuries, games missed, and days spent injured. Methods This study retrospectively looked at Premier League and Bundesliga players who sustained injuries during the 2021/2022 and 2022/2023 season. Injured players were identified on the publicly available online database Transfermarkt. Information regarding the number and characteristics of the injuries was extracted and categorized according to each season. To evaluate the potential complications arising from these injuries, multivariate regression models were employed. The models adjusted for age, minutes played, and appearances. Results There were significantly increased odds of muscle injuries sustained by players during the World Cup season in the Premier League (OR:1.58; 95% CI [1.25,2.01];p<0.001) and foot and ankle injuries in the Bundesliga (OR:2.22; 95% CI [1.42,2.62];p<0.001). Both leagues saw increased odds of knee injuries (OR:1.49; 95% CI [1.07,2.10];p=0.021) (OR:1.41; 95% CI [1.05,1.91];p=0.025). There was a significant decrease in minutes played by injured players (p=0.001) in the Premier league and injured Bundesliga players saw a significant increase in days spent injured from 26.23 days to 30.37 days (p=0.033). Conclusions There was a significant increase in the rate of injuries sustained by players in English and German leagues during the World Cup Season compared to a normal season with increased odds of injuries such as muscle injuries and knee injuries. A midseason slot may not be the best time to schedule a World Cup.