Video Analysis and Verification of Direct Head Impacts Recorded by Wearable Sensors in Junior Rugby League Players

Abstract

Background Rugby league is a high-intensity collision sport that carries a risk of concussion. Youth athletes are considered to be more vulnerable and take longer to recover from concussion than adult athletes. Purpose To review head impact events in elite-level junior representative rugby league and to verify and describe characteristics of X-patchTM-recorded impacts via video analysis. Study Design Observational case series. Methods The X-patchTM was used on twenty-one adolescent players (thirteen forwards and eight backs) during a 2017 junior representative rugby league competition. Game-day footage, recorded by a trained videographer from a single camera, was synchronised with X-patchTM-recorded timestamped events. Impacts were double verified by video review. Impact rates, playing characteristics, and gameplay situations were described. Results The X-patchTM-recorded 624 impacts ≥ 20g between game start and finish, of which 564 (90.4%) were verified on video. Upon video review, 413 (73.2%) of all verified impacts ≥ 20g where determined to be direct head impacts. Direct head impacts ≥ 20g occurred at a rate of 5.2 impacts per game hour; 7.6 for forwards and 3.0 for backs (range = 0–18.2). A defender’s arm directly impacting the head of the ball carrier was the most common event, accounting for 21.3% (n = 120) of all impacts, and 46.7% of all “hit-up” impacts. There were no medically diagnosed concussions during the competition. Conclusion The majority (90.4%) of head impacts ≥ 20g recorded by the X-patchTM sensor were verified by video. Double verification of direct head impacts in addition to cross-verification of sensor-recorded impacts using a secondary source such as synchronised video review can be used to ensure accuracy and validation of data.

Quantification of Head Acceleration Events in Rugby League: An Instrumented Mouthguard and Video Analysis Pilot Study

“…However, to fully understand head acceleration exposure in rugby league, it is important to consider HAE that occur after the initial collision (e.g., secondary contact and ground contact). These HAE may not be detected by video analysis alone yet accounted for a considerable proportion of HAE in the present study and a similar instrumented ear patch study in junior rugby league [17]. Approximately one-quarter of HAE were indirect HAE, which led to significantly greater ∆PAV than direct HAE.…”

“…iMG have been used to measure HAE in rugby union [15,16] and American Football [8], but not in rugby league. The combination of qualitative video analysis with objective kinematic measures can allow us to identify the contact events which lead to the highest magnitude and frequency of HAE [8,15,17]. The aim of this study was to identify and quantify HAE sustained during competitive men's professional rugby league matches based on tackle stage, head loading type and player role.…”

Influence of the frame of reference on head acceleration events recorded by instrumented mouthguards in community rugby players

“…2 With such growing concern, there is currently a considerable appetite for on-field instrumentation that may monitor significant head acceleration events (HAEs) in real time. [3][4][5][6][7] Most collision sports require athletes to wear mouthguards for participation, therefore making it easier to get athlete buy-in for wearing an instrumented version. Coupling of the mouthguard instrumentation to the dentition of the athlete…”

“…According to PubMed, in 2021, there was a 1200% increase in the number of publications about concussions in rugby compared with 2010 2. With such growing concern, there is currently a considerable appetite for on-field instrumentation that may monitor significant head acceleration events (HAEs) in real time 3–7. Most collision sports require athletes to wear mouthguards for participation, therefore making it easier to get athlete buy-in for wearing an instrumented version.…”

“…Therefore, instrumented mouthguards (iMGs) show substantial promise for improving accuracy in real-time measurement of HAE in field sports 9–12. The data collected can be used to improve player welfare by informing decisions regarding training loads 6 13. For clinicians and sports scientists, the hope is that real-time on-field evaluation of head impacts will lead to earlier detection of potential injurious events, support earlier medical intervention and removal from play for at-risk players 14…”