845 MEP168 – The incidence of head acceleration events (HAEs) and proportion of tackles and carries resulting in HAEs in professional rugby union matches using instrumented mouthguards (iMGs)

AbstractBackground Limited research has investigated head acceleration events (HAEs) in rugby union, despite their potential relevance for long-term player health. Objective Describe and compare the incidence of HAEs and proportion of tackles and carries resulting in HAEs in elite men's rugby union using iMGs and video analysis. Design Prospective cohort. Setting Rugby players from Super Rugby (SR) and Currie Cup (CC) in the 2023 season. Participants One-hundred and three players (n=17 SR, n=86 CC) across 836 player-matches (n=167 SR, n=669 CC). Main Outcome Measurements Incidence rates were calculated as the number of HAEs (recorded by iMGs) per player-hour and presented across a range of peak linear acceleration thresholds. Proportions were calculated as the percentage of tackles and ball-carries resulting in an HAE >20g. Values are reported with 95% confidence intervals (CI) for the Poisson distribution. Results The incidence (CI) of HAEs per player-hour for forwards, for SR vs.CC players was 6.28 (2.00–12.00) vs.5.21 (1.00–10.00) at the 20–40g range (p=0.006), 1.25 (0.00–4.00) vs.0.73 (0.00–3.00) at 40–60g (p<0.001), and 0.28 (0.00–2.00) vs.0.14 (0.00–1.00) at >60g (p=0.044). For backs, incidence rates were 4.95 (1.00–10.00) vs.2.45 (0.00–6.00) at 20–40g (p<0.001), 0.74 (0.00–3.00) vs.0.41 (0.00–2.00) at 40–60g (p=0.007), and 0.17 (0.00–1.00) vs.0.09 (0.00–1.00) at >60g (p=0.188). The proportion (CI) of tackles to result in an HAE >20g was 27.06% (17.00–38.00) vs.19.01% (11.00–28.00), for SR and CC (p<0.001). The proportion (CI) of carries to result in an HAE >20g was 30.78% (20.00–42.00) vs.20.35% (12.00–30.00) (p<0.001). Conclusions Incidence of HAE were significantly greater for SR vs. CC forwards in all HAE ranges, and significantly greater for SR vs. CC backs in all HAE ranges except >60g. The proportion of tackles and carriers resulting in HAE >20g was significantly greater in SR showing differences between men's competitions exist.