Collisions in junior rugby: Incidence, magnitude and the potential of headgear to reduce impact accelerations

Abstract

Introduction: The safety and neurological health of rugby union athletes receiving concussive and sub-concussive impacts during the sport remains a public health concern. Rugby has been found to be the contact sport with the highest concussion incidence and a predictor of severe injury relative to other sports. While there has been growing rugby collision research, there is still relatively little research measuring head impacts forces and investigating their influence on cognition and brain structure and function with junior rugby players. Additionally, more research is required that examines novel headgear models' ability to attenuate impact forces. This study aimed to measure the incidence and magnitude of head accelerations from collisions in Year 8 players. Methods: Nineteen Year 8 male rugby players and 12-13 years wore instrumented mouthguards during all games and contact trainings. The collisions were video verified and coded according to relevant rugby and biomechanical descriptors. Results: 958 verified HAEs were recorded during the season. Of these, 85.2% involved direct head contact and 14.8% involved indirect contact elsewhere on the body. Backs experienced fewer HAEs than forwards. Incidence range per player was 7 to 246 HAEs across the season, with an average of 50.4. Average PLA was 17.54 g at trainings and 21.73 g at games. Average PRA was 1732.53 rads/s2 at training and 2247.83 rads/s2 at games. Backs experienced significantly higher PLA (p=.014, Cohen’s d=.168) and PRA was (p=.004, Cohen's d=.198) than forwards. PRA and PLA in HAEs were lower when wearing headgear with PRA being significantly lower (p=<.001, Cohens d=.287). Well anticipated impacts resulted in lower PLA and PRA than both poorly (PLA p=.009, Cohen's d=.151; PRA p=.052) and non-anticipated (PLA p=.033, Cohen's d=.295; PRA p=.021, Cohen's d=.304) impacts. Conclusions: After the first season of data collection, we can report preliminary results. Headgear shows promise in this age-group in significantly reducing rotational acceleration to the head during rugby collisions and potential in reducing linear acceleration.