The effect of anthropometrics and maturity status on youth rugby head impact biomechanics

Rugby players undergo numerous head acceleration events (HAE), increasing injury risk versus non-contact sports. This prospective observational cohort study used instrumented mouthguards to analyze one season of boys (n = 60, mean age 14.5 years ± 1.1) and girls (n = 63, mean age 14.4 years ± 1.6) rugby players. Linear regression was used to calculate how height, weight, age and maturity offset (age relative to peak height velocity (PHV), only conducted with U13 boys (n = 19, mean age 13.3 years ± 0.5) and U14 girls (n = 22, mean age 12.8 years ± 0.8)) predicted HAE magnitude and seasonal count/hourly incidence. It was hypothesized that taller, heavier, older and more physically mature players would have increased HAE incidence and magnitude. Girls' age significantly predicted seasonal HAEs (p = .001) and mean PRA (p = .035). Boys' height significantly predicted seasonal (p = .005) and hourly (p = .011) HAEs. Physical maturity did not significantly predict HAE seasonal or hourly incidence for either gender, but girls' maturity offset negatively predicted the likelihood of HAEs ≥ 30 g (p = .008). However, the opposite was seen with boys with maturity offset being a significant positive predictor of these high magnitude HAEs (p = .024). Findings may guide load management, injury prevention and coaching considerations though the large variations in incidence and magnitude underscore the need for individualized player loading. Further research is needed to explore additional elements that influence HAE incidence and magnitude.