IPPON trial

Rationale
Judo is the most practiced combat sport in the Netherlands. The reported injury incidence is 4.3 per 1000 practicing hours and the prevalence is 41% within three months. Recently, we systematically developed the Injury Prevention and Performance Optimisation (IPPON) intervention. It’s effectiveness on injury reduction is yet unknown.

Objective
The primary aim is to evaluate the effectiveness of the IPPON intervention on the reduction of judo injury prevalence. The secondary aims are to evaluate the incidence and prevalence of substantial injuries, time-loss injuries, recurrence rates, performance parameters, judo trainer and athletes compliance and safety of the program.

Hypothesis
The hypothesis is that the IPPON intervention will reduce the risk of judo injuries.

Study design
Two-armed cluster Randomized controlled trial (RCT)

Study population
In order to be eligible to participate in this study, a subject must meet all of the following inclusion criteria:
• Participants are judo athletes
• Participants are ≥ 12 years of age
• Participants are willing to perform an exercise warm-up prevention programme at least twice per week
• Participants understand the Dutch language

Intervention
The intervention group will be instructed to use the trainer-supervised IPPON intervention at least 2 times a week. The control group will be instructed to continue their usual warm-up. The intervention includes 12 exercises. The exercises are classified in three categories, namely 1) flexibility and agility, 2) balance and coordination and 3) strength and stability. Exercises focus on the prevention of shoulder-, knee and ankle injuries. The warm-up has a total duration of 10 till 15 minutes.

Main study parameters/endpoints
Primary outcome is the overall injury prevalence (%) over a 6-months period, measured at two-weekly intervals with a modified translated version of the Oslo Sport- and Trauma Research Centre (OSTRC) questionnaire and exposure and compliance questions. Secondary outcomes include injury incidence, incidence and prevalence by anatomical location, time-loss (time to return to play), acute and overuse injury recurrence rates (<2 months after return to play), trainer and athletes compliance and adverse events. Estimates for the primary outcome and associated 95% confidence intervals will be obtained using generalized estimating equation models.

Statistical analysis
We will use descriptive statistics to present the baseline characteristics, the results of the OSTRC survey, self-reported time loss and compliance. We compare the intervention and control groups’ baseline characteristics using unpaired t-tests, Mann-Whitney-U and Fisher exact tests as appropriate. A p≤0.05 was considered statistically significant for all analyses. For the primary outcome, period injury prevalence rates will be calculated as the number of participants reporting an injury / total number returned questionnaires per injury survey instance.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness
The presented exercises are commonly used in sports, but they are not systematically used as part of the warm up of the judo training. We know that these exercises have hardly any risk. Participants have to fill in questionnaires every fortnight which takes a few minutes of their time.

The hypothesis is that the IPPON intervention will reduce the risk of judo injuries.

Start intervention: september 2019

The IPPON intervention. The exercises of the IPPON intervention are classified in three categories, namely 1) balance and coordination and 2) flexibility and agility and 3) power and stability. All exercises are focussed on the prevention of shoulder-, knee and ankle injuries. The warming-up has a total duration of 10 till 15 minutes.