Background Exercise programmes aimed at reducing injury have been shown to be efficacious for some non-collision sports, but evidence in collision sports such as rugby union is lacking.

Objective To evaluate the efficacy of an evidence-informed injury prevention exercise programme in reducing match injuries in adult community rugby union players.

Design Prospective cluster randomised (single-blind) controlled trial. Clubs were the unit of randomisation.

Setting English adult community clubs (2015–2016 season) with a formally qualified medical professional to diagnose and report match-injuries.

Participants 860 clubs were invited to participate of which 81 volunteered and were randomly assigned. Data was received from 41 clubs (control, 19; intervention, 22).

Interventions A 42-week exercise programme comprising 6-week graduated exercise blocks was introduced during pre-season. The control programme reflected ‘normal practice’ exercises, whereas the intervention focused on proprioception, balance, cutting, landing, and resistance exercises.

Main Outcome Measurements Match-injury incidence and burden for: all ≥8 days time-loss injuries and targeted (lower-limb, shoulder, head and neck, excluding fractures and lacerations) ≥8 days time-loss injuries.

Results Poisson regression identified unclear differences between groups for overall injury incidence (rate ratio (RR), 90% confidence interval (CI)=0.9, 0.6–1.3) and injury burden (RR, 90% CI=0.8, 0.5–1.4). A likely beneficial difference in targeted injury incidence (RR, 90% CI=0.6, 0.4–1.0) was identified, with ∼40% lower lower-limb incidence (RR, 90% CI=0.6, 0.4–1.0) and ∼60% lower concussion incidence (RR, 90%CI=0.36, 0.18–0.70) in the intervention group. Completing the intervention at least once per week was associated with a likely beneficial difference between groups (intervention n=15, control n=13; RR, 90% CI=0.7, 0.4–1.0).

Conclusions This movement-control injury-prevention programme appeared efficacious, with likely beneficial differences for lower-limb injuries and concussion for the treatment clubs. Targeted injury incidence was ∼30% lower when 1 or more intervention sessions were completed each week.