Judo is a popular international combat sport with an estimated 20 million active participants worldwide. Judo is characterised by the combination of balance, coordination, flexibility, agility, speed and strength with the aim to incapacitate their opponent. It is demanding of the neuromuscular and physical capacity of athletes. Participation in judo entails a substantial risk of injury in both elite and recreational judo. Injury prevention programmes in other sports have been proven effective in reducing injury rates for elite and recreational athletes. In judo, research on exercise-based prevention is limited to the description of injury prevention programmes, but the effectiveness of these programmes has never been evaluated. The main objective of our study was to evaluate the effectiveness of the bottom-up developed trainer-based IPPON intervention on the performance parameters compared with the usual warm-up in judo athletes. The secondary objectives were to evaluate injury severity, injury incidence, location-specific prevalences, time loss and sudden and gradual onset injury recurrence rates. We hypothesised that the IPPON intervention would increase performance parameters and reduce the overall injury prevalences. The IPPON intervention is an injury prevention programme designed specifically to reduce injuries in judo athletes. IPPON intervention mainly focuses on preventing musculoskeletal injuries of the shoulder, knee and ankle. The IPPON intervention consists of 36 exercises divided into (1) flexibility and agility, (2) balance and coordination and (3) strength and stability. Each category consisted of 12 exercises with 3 levels of difficulty. Athletes performed 4 exercises per category and thus 12 exercises at the start of the training at least two times per week. Prior to the intervention exercises, athletes completed running exercises and falling techniques. Athletes in the control group were instructed to continue their usual warm-up and regular judo practice as warm-up prior to training or competition is standard routine in judo. The duration of the IPPON intervention was aligned with the average duration of the usual warm-up in the control groups. Although, not measured in the study procedure, the approximate duration of warm-up was 15 min in both groups. The primary outcome was the performance parameters (Judo-Specific Special Conditioning Test, Isometric/Dynamic Judogi Grip Strength Test, Upper and Lower Extremity Y Balance Test, Upper Extremity Internal/External Rotation Strength Test, Lower Extremity Hamstring/Quadriceps Strength Test) over 8 weeks of follow-up, and secondary outcome was the overall injury prevalences (injury severity, injury incidence, location-specific prevalences, time loss and sudden and gradual onset injury recurrence rates) measured with the Turkish translation of the Oslo Trauma Research Center Overuse Questionnaire (OSTRC-O) at 2 weekly intervals over 16 weeks of follow-up.
