O'Connor Kathryn L, Peeters Thomas, Szymanski Stefan, Broglio Steven P
NeuroTrauma Research Laboratory, University of Michigan School of Kinesiology, Ann Arbor, MI, USA.
Erasmus School of Economics, Postbus 1738, 3000 DR, Rotterdam, The Netherlands.
Ann Biomed Eng. 2017 Aug;45(8):1985-1992. doi: 10.1007/s10439-017-1843-3. Epub 2017 Apr 28.
Helmeted impact devices have allowed researchers to investigate the biomechanics of head impacts in vivo. While increased impact magnitude has been associated with greater concussion risk, a definitive concussive threshold has not been established. It is likely that concussion risk is not determined by a single impact itself, but a host of predisposing factors. These factors may include genetics, fatigue, and/or prior head impact exposure. The objective of the current paper is to investigate the association between cumulative head impact magnitude and concussion risk. It is hypothesized that increased cumulative magnitudes will be associated with greater concussion risk. This retrospective analysis included participants that were recruited from regional high-schools in Illinois and Michigan from 2007 to 2014 as part of an ongoing study on concussion biomechanics. Across seven seasons, 185 high school football athletes were instrumented with the Head Impact Telemetry system. Out of 185 athletes, 31 (17%) sustained a concussion, with two athletes sustaining two concussions over the study period, yielding 33 concussive events. The system recorded 78,204 impacts for all concussed players. Linear acceleration, rotational acceleration, and head impact telemetry severity profile (HITsp) magnitudes were summed within five timeframes: the day of injury, three days prior to injury, seven days prior to injury, 30 days prior to injury, and prior in-season exposure. Logistic regressions were modeled to explain concussive events based on the singular linear acceleration, rotational acceleration, and HITsp event along with the calculated summations over time. Linear acceleration, rotational acceleration, and HITsp all produced significant models estimating concussion (p < 0.05). The strongest estimators of a concussive impact were the linear acceleration (OR = 1.040, p < 0.05), rotational acceleration (OR = 1.001, p < 0.05), and HITsp (OR = 1.003, p < 0.05) for the singular impact rather than any of the cumulative magnitude calculations. Moreover, no cumulative count measure was significant for linear or rotational acceleration. Results from this investigation support the growing literature indicating cumulative magnitude is not related to concussion likelihood. Cumulative magnitude is a simplistic measure of the total exposure sustained by a player over a given period. However, this measure is limited as it assumes the brain is a static structure unable to undergo self-repair. Future research should consider how biological recovery between impacts may influence concussion risk.
佩戴头盔的撞击装置使研究人员能够在体内研究头部撞击的生物力学。虽然撞击强度增加与更高的脑震荡风险相关，但尚未确定明确的脑震荡阈值。脑震荡风险很可能不是由单次撞击本身决定的，而是由许多诱发因素决定的。这些因素可能包括遗传、疲劳和/或既往头部撞击史。本文的目的是研究累积头部撞击强度与脑震荡风险之间的关联。研究假设累积强度增加将与更高的脑震荡风险相关。这项回顾性分析纳入了2007年至2014年从伊利诺伊州和密歇根州的地区高中招募的参与者，作为一项正在进行的脑震荡生物力学研究的一部分。在七个赛季中，185名高中足球运动员佩戴了头部撞击遥测系统。在185名运动员中，31人（17%）发生了脑震荡，在研究期间有两名运动员发生了两次脑震荡，共发生33次脑震荡事件。该系统记录了所有脑震荡球员的78204次撞击。在五个时间段内对线性加速度、旋转加速度和头部撞击遥测严重程度剖面（HITsp）强度进行了求和：受伤当天、受伤前三天、受伤前七天、受伤前30天以及赛季前的暴露期。基于单次线性加速度、旋转加速度和HITsp事件以及随时间计算的总和，建立逻辑回归模型来解释脑震荡事件。线性加速度、旋转加速度和HITsp均产生了估计脑震荡的显著模型（p<0.05）。对于单次撞击，脑震荡撞击的最强预测因子是线性加速度（OR=1.040，p<0.05）、旋转加速度（OR=1.001，p<0.05）和HITsp（OR=1.003，p<0.05），而不是任何累积强度计算。此外，对于线性或旋转加速度，没有累积计数测量是显著的。这项调查的结果支持了越来越多的文献表明累积强度与脑震荡可能性无关。累积强度是对运动员在给定时间段内承受的总暴露的一种简单衡量。然而，这种衡量方法是有限的，因为它假设大脑是一个无法自我修复的静态结构。未来的研究应该考虑撞击之间的生物恢复如何影响脑震荡风险。
