Document Type

Journal Article

Publication Title

Sports Medicine - Open








School of Engineering / Australian Centre for Research into Injury in Sport and its Prevention (ACRISP)




National Health and Medical Research Council / University of Newcastle / National Rugby League / Mooney-Reed Charitable Foundation / ImPACT Applications Inc. / Spaulding Research Institute


Carey, L., Terry, D. P., McIntosh, A. S., Stanwell, P., Iverson, G. L., & Gardner, A. J. (2021). Video analysis and verification of direct head impacts recorded by wearable sensors in junior rugby league players. Sports Medicine-Open, 7, article 66.


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.



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Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.