A biomechanical comparison of concussion and head acceleration events in elite-level American football and rugby union

Abstract: Elite-level American football and rugby union are two high-contact sports with growing clinical and legal concerns over player safety, necessitating a comparative analysis. A biomechanical comparison of 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. Overall, elite-level rugby union appears less favourable than American football in in almost all metrics pertinent to concussion and HAE exposure in the biomechanical comparison undertaken. The findings highlight the critical importance of independence, scientific rigour, and transparency in future concussion and HAE biomechanics research and real-world implementation, ensuring the development of more effective mitigation strategies.