LAUSR

Objectives To evaluate the effectiveness of a trainer-supervised judo-specific injury prevention warm-up programme on overall injury prevalence. Methods We conducted a two-arm, cluster randomised controlled trial; the Injury Prevention and Performance Optimization Netherlands (IPPON) study. Judo athletes aged≥12 years were randomised by judo school to IPPON intervention or control group who performed their usual warm-up. Primary outcome was overall injury prevalence (%) over the follow-up period (16–26 weeks) measured fortnightly with the Oslo Sports and Trauma Research Centre Questionnaire. A modified intention-to-treat analysis was performed due to COVID-19, with estimates for the primary outcome obtained using generalised linear mixed models. Secondary outcomes included: prevalence of severe injuries, overall incidence, time-loss injuries, exposure, adherence and experiences of trainers and athletes. Results 269 judo athletes (IPPON: 117, Control: 152) were included. Mean injury prevalence over 16–26 weeks was 23% (95% CI 20% to 26%) in the IPPON and 28% (95% CI 25% to 30%) in the control group. We observed no significant difference of all reported injuries (OR 0.72 in favour of the IPPON group; 95% CI 0.37 to 1.39). Secondary outcomes also demonstrated no significant differences between groups. Specifically, no significant difference of severe injuries was reported (OR 0.80 in favour of the IPPON group; 95% CI 0.36 to 1.78). All trainers and 70% of athletes perceived the IPPON intervention as successful. Conclusion The IPPON intervention did not significantly reduce the overall and severe injury prevalence. Despite this, we suggest the IPPON intervention be considered as an useful alternative to regular judo warm-up, given the high adherence and the positive clinical experiences of trainers and athletes. Trial registration number NTR7698.