Effectiveness of a judo-specific injury prevention programme: A randomised controlled trial in recreational judo athletes

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.