Concussion and head acceleration exposure in elite rugby union and American football: Interpreting indicative trends

Abstract

Elite-level American football and rugby union are two high-contact sports with growing clinical and legal concerns over player safety. A comparison of current indicative trends in concussion and head acceleration events (HAEs) in elite-level American football and rugby union was undertaken. Rugby union players have a greater number of professional playing years and matches available in a season than their American football counterparts. Rugby union players have a greater number of concussions reported per match and a higher proportion of concussions occurring during training sessions, based on National Football League (NFL) and Rugby Football Union (RFU) injury reports. Preliminary findings indicate that rugby union forwards experience a higher incidence of HAEs per player match over lower and higher magnitude thresholds, than American football defensive players. Taken collectively, current evidence indicates a trend toward greater reported exposure in elite-level rugby union across several key metrics. These patterns highlight the need for independent, transparent, and scientifically rigorous research to better understand concussion and HAE biomechanics and to support the development of effective mitigation strategies in contact sport.