This study aimed to translate and culturally adapt the Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSTRC-O) and the Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC-H) into the Japanese context. The validity and reliability of these translated questionnaires examining overuse injuries and health problems among Japanese university athletes were also examined. The translation was performed following an internationally recognized methodology. A total of 145 athletes were tracked over 10 consecutive weeks and four questions were added in the 10th week to examine the questionnaires’ content validity. Test-retest analysis for reliability was performed 24–72 hours after the 10th week of registration. Internal consistency was determined by calculating Cronbach’s a during the cohort study. No major disagreements were found in the translation process. The translated questionnaires had high acceptance and compliance, with an average response rate of over 80% throughout the 10-week cohort study. Most participants reported that the questionnaires were not difficult to complete, there were no items they wanted to change or add, and that the web-based technique worked effectively. Good test-retest reliability and high internal consistency was observed in the translated questionnaires. The translated questionnaires were found to be valid, reliable, and acceptable for medically monitoring Japanese athletes.

Monitoring the health of athletes is important for their protection, and questionnaires such as those produced by the Oslo Sports Trauma Research Center (OSTRC) are a valuable tool in this process. In 2020, several changes were made to the OSTRC questionnaires (OSTRC-O, OSTRC-H), including changes to the wording, structure, and logic of the original questionnaires. In the present study, the Japanese versions of the OSTRC questionnaires (OSTRC-O.JP, OSTRC-H.JP) were revised to meet the requirements of the updated versions and to analyse new and previously collected data to illustrate the impact of the changes on Japanese athletes. Proposed changes were categorized as minor or more substantial; minor changes were effected to the questionnaire instructions and to the wording of all four questions, and more substantial changes were made to the wording of question 2. The updated questionnaires also included changes to questionnaire logic and answer categories. To assess the consequences of the changes to the wording of question 2, 101 athletes were asked to complete the OSTRC-H.JP, which included both the original and updated versions of question 2, over 10 consecutive weeks. We calculated the number of health problems identified when new gatekeeper logic was and was not applied, using 1585 OSTRC-H.JP responses to assess the consequences of the changes to the questionnaire logic. The kappa coefficient, which measures the level of agreement between the responses to question 2 of the original and updated versions, was high. By applying gatekeeper logic, there was a remarkable reduction in the number of injuries and illnesses among all health problems but less reduction in substantial health problems and time loss health problems. These changes will make it easier for Japanese athletes to complete the questionnaires and improve the quality of collected data.

Despite extensive studies on the incidence and characteristics of football (soccer) injuries using a time-loss definition, the exact magnitude of injuries and illnesses in football players remains unclear. This study aimed to examine the prevalence and burden of health problems among university football players based on all physical complaints. Ninety-four male university football players were prospectively followed up during the 2020 competitive season in Japan. The study period was divided into the self-training period (SP) and the football period (FP). All participants were asked to complete the Japanese version of the Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC-H2.JP) every Sunday. The main outcome measures were the prevalence of all health problems and substantial health problems and their burdens. The average response rate to the OSTRC-H2.JP was 88.8% [95% CI, confidence interval: 87.7%-89.9%]. Overall, the average weekly prevalence of all health problems was 19.7% [95% CI: 18.3%-21.1%]. During the FP, the average weekly prevalence of all health problems and substantial health problems were 22.9% [95% CI: 21.0%-24.7%] and 15.3% [95% CI: 13.7%-16.9%], respectively. Injuries were the main problem, with traumatic injuries in the ankle, thigh, and foot representing the greatest burden. This study indicated that approximately 20% of university football players experienced injuries or illnesses. Traumatic injuries in the ankle, thigh, and foot represented the greatest burden on self-reported reliance using broad definitions of injury and illness. Therefore, injury prevention should focus on preventing these complaints.

Background Epidemiological data on sports injuries and illnesses depend on the surveillance methodology and the definition of the health problems. The effect of different surveillance methods on the data collection has been investigated for overuse injuries, but not for other health problems such as traumatic injuries and illnesses. Purpose The purpose of this study was to investigate the new surveillance method developed by the Oslo Sports Trauma Research Center (OSTRC), which is based on any complaint definition (new method), to identify health problems compared with the traditional surveillance method, which is based on time loss definition. Study design Descriptive epidemiology study Methods A total of 62 Japanese athletes were prospectively followed-up for 18 weeks to assess differences in health problems identified by both new and traditional methods. Every week, the athletes completed the Japanese version of the OSTRC questionnaire (OSTRC-H2.​JP), whereas the teams’ athletic trainers registered health problems with a time loss definition. The numbers of health problems identified via each surveillance method were calculated and compared with each other to assess any differences between their results. Results The average weekly response rate to the OSTRC-H2.​JP was 82.1% (95% CI, 79.8–84.3). This new method recorded 3.1 times more health problems (3.1 times more injuries and 2.8 times more illnesses) than the traditional method. The difference between both surveillance methods’ counts was greater for overuse injuries (5.3 times) than for traumatic injuries (2.5 times). Conclusions This study found that the new method captured more than three times as many health problems as the traditional method. In particular, the difference between both methods’ counts was greater for overuse injuries than for traumatic injuries. Level of evidence 2b