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.

Injury can possibly change an athlete's career. To date, few epidemiological studies have been made of amateur soccer players. More data is needed to allow medical professionals to develop realistic injury prevention and conditioning programs for the amateur level. The purpose of this study was to determine injury incidence, common injury types and body regions, and pain in amateur soccer players. Soccer-related injury and pain data were collected daily in June 2016 thorough October 2017 involving 76 amateur soccer players from two teams. Overall injury incidence was 69 injuries and 2.72/1000 player hours. Acute injuries were 52 (2.05/1000 player hours) and chronic injuries were 17 (0.67/1000 player hours). Most acute injuries occurred during a game (1.99/1000 player hours). In terms of body regions, ankle injury (27.5%) was the most common, followed by knee (15.9%), and thigh (9.0%). Pain incidence was reported 1042 (41.10/1000 player hours). The highest pain incidence was reported during a game (36.9/1000 player hours). The most common location of pain was foot/toe (5.80/1000 player hours), followed by lateral ankle (5.21/1000 player hours), anterior thigh (3.98/1000 player hours), and groin (3.27/1000 player hours). Type of injury, location of injury, and the higher incidence of injury during a game, as opposed to training, were the same as other studies. The pain incidence rate was higher than injury incidence. More epidemiological studies are needed in amateur sports to better understand athletes' injuries and pain and be able to develop an appropriate injury prevention strategy.