BACKGROUND: After COVID-19 lockdown, studies across Europe and Asia examined its effect on professional soccer injury rates and severity
however, COVID-19 lockdown influence on injuries in United States men's professional soccer has not been evaluated. HYPOTHESIS: Injury and illness rates during the 2020 season were higher than the previous 2 seasons. STUDY DESIGN: Retrospective observational cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: Medical staff from participating Major League Soccer (MLS) clubs entered injuries and athletic exposures during the study period into a league-wide electronic medical record system. Injury rate and severity were analyzed to examine differentials between the 2020 COVID season and historical controls. RESULTS: The injury incidence rate per 1000 hours in 2020 was 10.8, ie, higher than 2018 (5.4) and 2019 (5.0) ( CONCLUSIONS: During 2020, there were significant increases in incidence rates of overall injuries, training injuries, lower extremity muscular injuries, ACL injuries, concussions, and non-COVID illness, along with a higher percentage of players missing >
90 days compared with the 2 previous seasons. CLINICAL RELEVANCE: These results may help clarify the effects of future MLS inseason work stoppages and periods of restricted training.