813 BO02 – Can collision and instrumented mouthguard data inform rugby match exposure in the future? An example using rugby unionand rugby league data in England

Background Despite growing interest in the long-term effects of head acceleration events (HAE) in rugby union (RU) and league (RL), current match exposure guidelines are based on research surrounding injuries. Objective 1) Estimate the expected number of collisions from match event data (video analysis) and HAEs (instrumented mouthguards; iMGs) per full game equivalent (FGE) played. 2) Evaluate the impact of different FGE limits on the number of collisions and HAEs. Design Retrospective cohort Setting Professional men's RU (1/9/2021–31/7/22) and RL (1/1/2022–1/12/22). Participants RU: 598 players (347 forwards, 251 backs); RL: 365 players (183 forwards, 182 backs). Assessment of Risk Factors The number of FGEs (total playing time in minutes divided by 80) for each player and positional group (forward or back) were used as independent variables to estimate expected collision and HAE counts. Main Outcome Measurements The total number of collisions were derived for each player by summing individual collision counts using match event data. HAE counts were estimated at four arbitrary HAE thresholds by multiplying individual collision event counts by the probability of a HAE above the threshold for that event. Results In RU and RL, forwards were involved in more collisions than backs per FGE. As the magnitude of HAE increased, the differences between forwards and backs reduced (e.g., 30 FGE RU forwards vs. RU backs; collisons 1674 [95% CI; 1663–1686] vs. 616 [602–625]; >20g HAE 169 [167–172] vs. 105 [103–108]). To reduce the number of collisions or >20g HAEs for 5% of players with the highest exposure, FGE limits would need reducing by 23% and 13% in RU or 24% and 10% in RL. Conclusions Using match event and iMG data has the potential to inform future match exposure exposure limits in rugby by providing expected collision and HAE counts for a variety of scenarios.