Factors Associated with Injuries and Gender Differences in Japanese Adolescent Athletes Returning to Sports Following the COVID-19 Restriction

Background: Because the worldwide spread of coronavirus disease 2019 has forced a moratorium on student sports activity in Japan, reports on its impact on sports injuries are limited given its novelty. This study aimed to determine the characteristics and gender differences of injuries in adolescent athletes after returning to sport following restriction of club activities due to the coronavirus pandemic. Methods: An online retrospective questionnaire was distributed to 500 adolescent athletes who belong to school sports clubs in Japan from March 1–19, 2021. An anonymous questionnaire was created before and after the restriction of sports activities following the declaration of the first state of emergency of the COVID-19 pandemic in Japan. Subsequently, 258 valid responses were obtained, and injury-related characteristics were compared between injured and non-injured athletes after returning to sports and between genders for injured athletes. There were no differences in the body areas of sports injuries between males and females. Result: We found that injury experience before club activity restriction was significantly associated with injury after returning to sports (p < 0.001). Moreover, practice time increased before and after the restriction in the injury group (p = 0.038). The injury rate was higher in females (p < 0.024), and the trauma rate was higher among males (p = 0.016). There were no differences in the body areas of sports injuries between males and females. Conclusions: Our results provide gender-differentiated ideas and suggestions as they relate to injury prevention once in adolescent athletes returning to sports after the coronavirus disease 2019 induced restriction of club activities. We show the need for injury rehabilitation and practice time control in adolescent athletes in the coronavirus disease 2019 setting.