Author(s): SPRIGGS, N., HAMLIN, M.J., HENLEY, S., STITT, D., KABALIUK, N., SWALE, A., MELZER, T., CLARK, A., ANDERSON, T., SNELL, D., HOLDSWORTH, S., ALEXANDER, K., BASU, A., MASTERS, R., DRAPER, N. , Institution: LINCOLN UNIVERSITY, NEW ZEALAND , Country: NEW ZEALAND, Abstract-ID: 492

INTRODUCTION:
There is growing concern in regard to rugby union player safety and ongoing medical problems following a concussion or long-term participation in the game. Because of the nature of rugby, players are exposed to repeated head acceleration events (HAE), potentially resulting in a concussion. These HAE can be direct (e.g. head-to-head contact) or indirect (e.g. whiplash from a tackle at the waist) and can be measured through Peak Linear Acceleration (PLA; g) and Peak Rotational Acceleration (PRA; rads/s^2) using instrumented mouthguards. Research on females and adolescent rugby players is sparse, yet they are a growing cohort wanting to play the game. It is also reported that adolescent females are at greater concussion risk and may experience concussions at a lower HAE threshold, compared to male and adult female players. Investigation of sex- and age-specific HAE magnitude and incidence is required for improving the safety of female adolescent rugby players and increase our understanding of how HAEs affect ongoing brain health.
METHODS:
Eighteen female rugby players aged 12-17 years, wore an instrumented mouthguard (HIT IQ Nexus) for all school and club games and contact trainings during the 2022 rugby season in New Zealand. All HAE above 8g were recorded by the instrumented mouthguard. All sessions were recorded to verify all mouthguard detected HAE. The total amount of data collected over the season was 708.5 rugby player hours (game 266.5; training 442).
RESULTS:
We found 1074 video-verified HAEs. Approximately half of these events (n = 548) were from direct head contact and 526 indirect impacts events not associated with head contact. Average impact per 1-hr of game exposure was 3.2 +/- 2.1 (mean +/- SD) and 1-hr of training exposure was 0.3 +/- 0.1. Although average impact incidence was significantly higher in games (p= <0.01) compared to trainings, game and training HAE magnitudes were not significantly different for PLA (p=0.81) or PRA (p=0.37). Games had an average PLA of 19.8 +/- 4.4 g, PRA of 1634 +/- 1372 rads/s^2, while trainings had an average PLA of 18.8 +/- 5.6 g and PRA of 1584 +/- 1145 rads/s^2. On average, each player experienced 2.0 +/- 2.2 HAE’s above 55 g across a season of rugby participation.
CONCLUSION:
Adolescent female rugby players are subject to a moderate number of HAE’s during the season, predominantly in games. Only 3% of HAE’s exceeded the 55 g threshold set by World Rugby for adult female players, which in our situation, under the new World Rugby laws would result in a single player being removed from play twice during a season of rugby participation. This study highlights the need for sex and age specific, objective data to measure head impact exposure in rugby union. Monitoring head impact magnitude and incidence is important for rugby safety and understanding the effect of concussive and non-concussive HAE in rugby union, both acutely and over the longer term.