The efficacy of a movement control exercise programme to reduce injuries in youth rugby

The incidence and severity of injury, as well as the overall burden of injury in the intervention group compared with the control group.
Details (location, nature, mechanism, severity) of all injuries related to participation in school rugby that incur a 24-hour or greater time loss from subsequent school rugby exposure for the 2015/16 winter term will be recoded on a standardised form. The medical diagnosis for each injury will be coded to three levels according to the Orchard Sports Injury Coding System (OSICS) version by an on-site medical professional.
Coaches of all individual teams will be provided an exposure and compliance report form to be completed on a weekly basis, detailing team-level training and individual match exposure, along with a compliance record in relation to the exercise programme.
Injury and exposure information will be prospectively collected for the entire duration of the schools rugby season from late August 2015 to December 2015.
Poisson regression, with adjustment for clustering by school, offset for player-hours of exposure, and adjustment for the aforementioned covariates (i.e., age/maturation status, playing position, playing experience, level of play, coaches’ attitude, and previous injury history) will be used to compare injury incidence and injury burden (injury incidence rate x mean absence per injury) between the trial arms. Injury severity will be compared between the trial arms using an identical model, but with a linear response distribution. Separate analyses will be conducted for match and training injuries. Interaction effects (e.g., maturation status x trial arm) will be examined for evidence of intervention effect modification.

1. The influence of coach attitudes on compliance and injury burden between the trial arms, in addition to changes in these through use of the exercise programmes.
2. The study design and both exercise programmes have been formulated in order to optimise compliance within the schools rugby setting. Nevertheless, this aspect will be monitored throughout the study. The coaches responsible for recording the weekly match and training exposure will also be responsible for recording whether or not the squad completed their allocated exercise programme. These data will be combined with exposure data in order to produce an index of compliance for all included teams (such as a percentage of exposures where the exercise programme was completed).
3. The attitudes, knowledge, and beliefs of coaches involved in leading the exercise programmes both before (August 2015) and after (December 2015) the intervention period. This will be undertaken by two paper-based questionnaires of all coaches involved in the study, one prior to study commencement and one shortly before study conclusion using a standardised questionnaire designed by the authors based upon previous work investigating similar features. The questionnaires will assess whether coaches in the different trial arms have differing baseline views on injuries and injury prevention in youth rugby, how these views are associated with compliance to their allocated exercise programme, and whether these views are altered as a result of implementing their allocated exercise programme.
4. The influence of compliance on injury burden will also be analysed. Compliance will be computed into two entities: coach compliance (% of exposures where exercise programme was completed) and player compliance (% of players that completed the exercise programme during each exposure). The product of these two proportions will be taken forward for analysis as the total compliance. Teams in both trial arms will be stratified into tertiles based on total compliance: low, intermediate, and high. Poisson regression will be used to investigate the influence of compliance to the exercise programme on the risk of injury, with the low compliance tertile in the control arm serving as the reference group.
5. Behavioural, attitudes and knowledge variables will be pre-coded and analysed in a number of different ways. Only coaches that complete the study and provide questionnaire responses for at least the pre-season questionnaire will be included in this analysis. These variables will be compared at baseline between the two trial arms and at the end of the intervention to assess any changes using both categorical and continuous data analysis. To analyse the influence of coach beliefs on compliance, linear regression analysis will be used with team compliance (%) as the dependent variable and questionnaire responses serving as the predictor variables. The responses to the questionnaire will also be compared between the compliance tertile groups using categorical data analyses. To investigate the influence of coach attitudes on injury burden, poisson regression, adjusted for clustering by school, will be used with injury burden (days/1000 player-hours) as the dependent variable and questionnaire responses serving as the predictor variables. The results will be presented as Relative Risk (RR) with 95% confidence intervals and p-values. Both sets of analyses will be adjusted for coaching experience (years) and coaching level, which will be recorded as part of the pre-season questionnaire.