Matthew Kitchin

Understanding how players experience head‐acceleration events (HAE) whilst playing rugby is a priority area of research. In both rugby union and league, video analysis frameworks have been developed to comprehensively define key features of contact events. However, these frameworks were developed prior to recent advances in our understanding regarding the proportion of HAEs that occur due to head‐to‐ground mechanisms and do not consider important post‐contact variables. Therefore, there is a need to supplement the existing frameworks in order to capture how players fall and land post‐tackle. This study used the Delphi method with an interdisciplinary, international team of researchers, coaches and video analysts (working with a variety of playing levels in rugby union and league) to establish a consensus for defining falling and landing events. Subsequently, a draft framework was developed on which the research team provided feedback via online meetings, culminating in the falling/landing framework that each member of the research team rated agreement on, via a nine‐point Likert‐type scale, with consensus deemed to be reached when the median score was ≥ 7. The median scores were 8.0 (7.8–8.0), 8.0 (7.0–9.0) and 8.0 (8.0–9.0) for ‘Additional Contextual Characteristics for Carry and Tackle Events,’ ‘Falling Characteristics of Tackle and Carry Events,’ and ‘Landing Characteristics of Tackle and Carry Events,’ respectively. This novel framework defines more comprehensive falling and landing variables to capture post‐contact injury and performance markers in both rugby union and league, through a standardised approach.

Background Head acceleration event (HAE) exposure is a concern in sport owing to potential effects on brain health. Despite growth in the sport's growing in popularity, HAE exposure in women’s rugby league has yet to be quantified. Objectives The aim of the study was to examine HAE incidence and probability across Women’s Super League rugby league players, including position- and player-specific HAE incidence and probability. Methods Instrumented mouthguards (iMGs) were worn by 136 players during the 2024 season, across 48 video-analysed matches, resulting in 568 player matches with iMG data. The incidence of HAEs and the probability of HAEs from ball-carries and tackle attempts were estimated using generalised linear mixed models and average positions on an individual-player basis. Results The average incidence of HAEs exceeding 25 g ranged from 0.40 to 0.65 per median playing time for back positions and 0.54 to 0.66 for forward positions. The probability of recording an HAE exceeding 25 g during a ball-carry was 1.33% and a tackle-attempt was 1.28%. Some individuals had higher HAE incidence and probability compared with position group means (e.g. one player exhibited an average of 1.77 HAEs exceeding 25 g per match, over double the average for their position). Conclusions This study quantifies HAE incidence and probability in women’s rugby league match-play, allowing for the comparison of HAE exposure with other sports. Overall, HAE incidence is lower than previously reported for men’s rugby league and for women’s rugby union. However, given elevated HAE incidence in some players, continued HAE monitoring using iMGs is necessary for managing the potential risks of HAE exposure.