Bagherian Amirhossein, Abbasi Ghiri Alireza, Ramzanpour Mohammadreza, Wallace James, Elashy Sammy, Seidi Morteza, Memar Marzieh
Department of Biomedical Engineering and Chemical Engineering, University of Texas at San Antonio, San Antonio, TX, United States.
Department of Mechanical Engineering, University of Texas at San Antonio, San Antonio, TX, United States.
Front Bioeng Biotechnol. 2025 Jan 14;12:1500786. doi: 10.3389/fbioe.2024.1500786. eCollection 2024.
Research on head impact characteristics, especially position-specific investigations in football, has predominantly focused on collegiate and professional levels, leaving a gap in understanding the risks faced by high school players. Therefore, this study aimed to investigate the effect of three factors-player position, impact location, and impact type-on the frequency, severity, and characteristics of impacts in high school American football. Additionally, we examined whether and how player position influences the distribution of impact locations and types.
Sixteen high school football players aged 14 to 17 participated in this study. Validated mouthguard sensors measured head impact kinematics, including linear acceleration, angular acceleration, and angular velocity across ten games, and were used to identify impact locations on the head. Video recordings verified true impacts, player position, and impact type at the moment of each recorded impact. Head impact kinematics were input into a head finite element model to determine the 95th percentile of the maximum principal strain and strain rate. Several novel and systematic approaches, such as normalization, binning, and clustering, were introduced and utilized to investigate the frequency and severity of head impacts across the three aforementioned factors while addressing some of the limitations of previous methodologies in the field. To that end, the number of recorded impacts for each player position during each game was divided by the number of players in that position, and then averaged across ten games. Instead of averaging, impacts were categorized into four severity bins: low, mid-low, mid-high and high. Clusters for the three factors were also identified according to the characteristics of impacts.
Results revealed that offensive linemen and running backs experienced a higher normalized frequency and more severe impacts across all head kinematics and brain tissue deformation parameters. Frontal impacts, resulting from "head-to-head" impacts, were the most frequent and severe impact locations. The distributions of impact location and type for each specific position were distinct. Offensive linemen had the highest proportion of frontal impacts, while quarterbacks and centerbacks had more impacts at the rear location. These findings can inform interventions in game regulations, training practices, and helmet design to mitigate injury risks in high school football.
关于头部撞击特征的研究，尤其是在橄榄球运动中针对特定位置的调查，主要集中在大学和职业水平，在了解高中球员面临的风险方面存在空白。因此，本研究旨在调查三个因素——球员位置、撞击位置和撞击类型——对高中美式橄榄球撞击的频率、严重程度和特征的影响。此外，我们还研究了球员位置是否以及如何影响撞击位置和类型的分布。
16名年龄在14至17岁的高中橄榄球运动员参与了本研究。经过验证的护齿传感器测量了头部撞击运动学数据，包括线性加速度、角加速度和角速度，这些数据来自十场比赛，并用于确定头部的撞击位置。视频记录验证了每次记录撞击时的真实撞击情况、球员位置和撞击类型。将头部撞击运动学数据输入头部有限元模型，以确定最大主应变和应变率的第95百分位数。引入并采用了几种新颖且系统的方法，如归一化、分箱和聚类，来研究上述三个因素下头部撞击的频率和严重程度，同时解决该领域先前方法的一些局限性。为此，每场比赛中每个球员位置的记录撞击次数除以该位置的球员人数，然后在十场比赛中进行平均。撞击不是进行平均，而是分为四个严重程度等级：低、中低、中高和高。还根据撞击特征确定了这三个因素的聚类。
结果显示，进攻线卫和跑卫在所有头部运动学和脑组织变形参数方面经历了更高的归一化频率和更严重的撞击。由“头部对头部”撞击导致的正面撞击是最频繁和最严重的撞击位置。每个特定位置的撞击位置和类型分布各不相同。进攻线卫正面撞击的比例最高，而四分卫和中后卫在后部位置的撞击更多。这些发现可为比赛规则、训练方法和头盔设计的干预措施提供参考，以降低高中橄榄球运动中的受伤风险。
