## Appendix A. Header Kinematics by Header Type and Preceding Ball Delivery Method
Brain injury and heading in soccer. _BMJ_**2003**, _327_ (Suppl. S4), 0310351. * _Queen et al. (2003)_ Queen, R.M. ; Weinhold, P.S. ; Kirkendall, D.T. ; Yu, B. Theoretical Study of the Effect of Ball Properties on Impact Force in Soccer Heading. _Med. Sci. Sports Exerc._**2003**, _35_, 2069-2076. [CrossRef]
* _Tierney (2022)_ Tierney, G. Concussion biomechanics, head acceleration exposure and brain injury criteria in sport: A review. _Sports Biomech._**2022**, _20_, 1-29. [CrossRef]
* _Tooby et al. (2022)_ Tooby, J.; Weaving, D.; Al-Dawoud, M.; Tierney, G. Quantification of Head Acceleration Events in Rugby League: An Instrumented Mouthupated and Video Analysis Pilot Study. _Sensors_**2022**, _22_, 584. [CrossRef]
* _Wu et al. (2016)_ Wu, L.C. ; Nangia, V.; Bui, K.; Hammooor, B.; Kurt, M.; Hernandez, F.; Kuo, C.; Camarillo, D.B. In Vivo Evaluation of Wearable Head Impact Sensors. _Am. Biomed. Eng._**2016**, _44_, 1234-1245. [CrossRef]
* _Kieffer et al. (2020)_ Kieffer, E.E. ; Vaillancourt, C.; Brolinson, P.G. ; Rowson, S. Using in-mouth sensors to measure head kinematics in rugby. In Proceedings of the IRCOBI Conference, Munich, Germany, 2020; Volume 13, pp. 846-858. * _Tysvaer et al. (1989)_ Tysvaer, A.T.; Storli, O.V. ; Bachen, N.I. Soccer injuries to the brain. A neurologic and electroencephalographic study of former players. _Acta Neurol. Scand._**1989**, _80_, 151-156. [CrossRef]
* _Naunheim et al. (2000)_ Naunheim, R.S. ; Standeven, J.; Richter, C.; Lewis, L.M. Comparison of impact data in hockey, football, and soccer. _J. Trauma Acute Care Surg._**2000**, _48_, 938-941. [CrossRef]
* _Football and Dementia--Are Football Being Protected Enough against the Risks of Brain Injury?\" Stewarts. Available online: [[https://www.stewartslav.com/news/football-and-dementia-are-players-getting-enough-protection-against-the-risks-of-brain-injury](https://www.stewartslav.com/news/football-and-dementia-are-players-getting-enough-protection-against-the-risks-of-brain-injury)]([https://www.stewartslav.com/news/football-and-dementia-are-players-getting-enough-protection-against-the-risks-of-brain-injury](https://www.stewartslav.com/news/football-and-dementia-are-players-getting-enough-protection-against-the-risks-of-brain-injury)) (accessed on 23 September 2022). * _Tierney et al. (2020)_ Tierney, G.J. ; Kuo, C.; Wu, L.; Weaving, D.; Camarillo, D. Analysis of head acceleration events in collegiate-level American football: A combination of qualitative video analysis and in-vivo head kinematic measurement. _J. Biomech._**2020**, _110_, 109969. [CrossRef]
* _McHugh (2009)_ McHugh, M.L. Lessons in biostatistics. _Biochem. Med._**2009**, _19_, 120-126. [CrossRef]
* _Landis and Koch (1977)_ Landis, J.R.; Koch, G.G. The Measurement of Observer Agreement for Categorical Data. _Biometrics_**1977**, _33_, 159-174. [CrossRef]
* _Rich et al. (2019)_ Rich, A.M.; Filben, T.M. ; Miller, L.E. ; Tomblin, B.T. ; Van Gorkom, A.R. ; Hurst, M.A. ; Barnard, R.T.; Kohn, D.S. ; Urban, J.E. ; Stitzel, J.D. Development, Validation and Pilot Field Deployment of a Custom Mouthpiece for Head Impact Measurement. _Ann. Biomed. Eng._**2019**, _47_, 2109-2121. [CrossRef]
* _Liu et al. (2020)_ Liu, Y.; Domeel, A.G.; Yousefsani, S.A.; Kondic, J.; Grant, G.; Zeineh, M.; Camarillo, D.B. Validation and Comparison of Instrumented Mouthguards for Measuring Head Kinematics and Assessing Brain Deformation in Football Impacts. _Ann. Biomed. Eng._**2020**, _48_, 2580-2598. [CrossRef]
* _Kieffer et al. (2020)_ Kieffer, E.E. ; Begonia, M.T. ; Tyson, A.M.; Rowson, S. A Two-Phased Approach to Quantifying Head Impact Sensor Accuracy: In-Laboratory and On-Field Assessments. _Ann. Biomed. Eng._**2020**, _48_, 2613-2625. [CrossRef]* Jones et al. (2022) Jones, B.; Tooby, J.; Weaving, D.; Till, K.; Owen, C.; Begonia, M.; Stokes, K.A. ; Rowson, S.; Phillips, G.; Hendricks, S.; et al. Ready for impact? A validity and feasibility study of instrumented mouthguards (iMGs). _Br. J. Sports Med._**2022**, _56_, 1171-1179. [CrossRef]
* Caccese et al. (2016) Caccese, J.B.; Lamond, L.C.