Tackle higher or lower? Simulation to evaluate how changing the tackle height would impact the number of concussions and head acceleration events in men’s professional rugby league

Objective To quantify concussion and head acceleration event (HAE) probability in rugby league tackles by tackle height and role and simulate seasonal counts across different tackle height distributions. Methods Using a prospective cohort study, data reflecting clinically diagnosed concussions (n=56) and HAEs (n=4632; measured via instrumented mouthguards from 23 081 tackles in 92 players) were collected during the 2023 men’s Super League season. Video analysis captured tackle heights for all concussive and accelerometer-measured tackles. Role-specific probabilities were calculated using cumulative link mixed models. Monte Carlo simulation quantified concussions and HAEs across the current tackle-height distribution and three lower tackle-height distributions (weighted redistribution (increased torso tackles), even redistribution (increased torso and lower body tackles) and observed law trial distribution). Results Ball-carriers experienced the highest concussion and HAE risk from head/neck contact compared with other tackle heights (eg, HAE ≥25 g; 2.7% vs 0.4%–1.1%), while tackler risk was similar. The number of ball-carrier concussions (16 vs 8–9) and HAEs (≥25 g; 830 vs 357–556) decreased with all lower tackle-height distributions. For tacklers, the only meaningful change was an increase in HAEs following the even redistribution of a lower tackle height (≥25 g; 2081 vs 2204). When considering both roles together, only even and weighted lower tackle-height redistributions reduced the total number of lower-to-moderate magnitude HAEs, with no meaningful differences observed for concussions or higher magnitude (≥55 g) HAEs. Conclusion Lowering the tackle height creates a protection paradox, benefiting ball-carriers, while potentially maintaining or increasing the risk for tacklers. Simulated findings may inform policy changes by estimating outcomes and allowing evaluation prior to implementation.