Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC.
Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, NC.
Med Sci Sports Exerc. 2020 Feb;52(2):449-456. doi: 10.1249/MSS.0000000000002144.
Head impact exposure (HIE) (i.e., magnitude and frequency of impacts) can vary considerably among individuals within a single football team. To better understand individual-specific factors that may explain variation in head impact biomechanics, this study aimed to evaluate the relationship between physical performance measures and HIE metrics in youth football players.
Head impact data were collected from youth football players using the Head Impact Telemetry System. Head impact exposure was quantified in terms of impact frequency, linear and rotational head acceleration, and risk-weighted cumulative exposure metrics (RWELinear, RWERotational, and RWECP). Study participants completed four physical performance tests: vertical jump, shuttle run, three-cone, and 40-yard sprint. The relationships between performance measures, and HIE metrics were evaluated using linear regression analyses.
A total of 51 youth football athletes (ages, 9-13 yr) completed performance testing and received combined 13,770 head impacts measured with the Head Impact Telemetry System for a full season. All performance measures were significantly correlated with total number of impacts in a season, RWELinear-Season, and all RWE-Game metrics. The strongest relationships were between 40-yard sprint speed and all RWE-Game metrics (all P ≤ 0.0001 and partial R > 0.3). The only significant relationships among HIE metrics in practice were between shuttle run speed and total practice impacts and RWELinear-Practices, 40 yard sprint speed and total number of practice impacts, and three-cone speed and 95th percentile number of impacts/practice.
Generally, higher vertical jump height and faster times in speed and agility drills were associated with higher HIE, especially in games. Physical performance explained less variation in HIE in practices, where drills and other factors, such as coaching style, may have a larger influence on HIE.
头部撞击暴露（HIE）（即撞击的幅度和频率）在单个橄榄球队内的个体之间可能有很大差异。为了更好地了解可能解释头部撞击生物力学个体差异的特定个体因素，本研究旨在评估青少年足球运动员的身体表现测量与 HIE 指标之间的关系。
使用头部撞击遥测系统从青少年足球运动员收集头部撞击数据。头部撞击暴露量通过撞击频率、线性和旋转头部加速度以及加权累积暴露指标（RWELinear、RWERotational 和 RWECP）来量化。研究参与者完成了四项身体表现测试：垂直跳跃、穿梭跑、三锥和 40 码冲刺。使用线性回归分析评估了性能测量值与 HIE 指标之间的关系。
共有 51 名青少年足球运动员（年龄 9-13 岁）完成了性能测试，并在整个赛季中接受了结合 Head Impact Telemetry System 测量的 13770 次头部撞击，共进行了 13770 次头部撞击，所有性能测量值均与赛季内总撞击次数、RWELinear-Season 和所有 RWE-Game 指标显著相关。与所有 RWE-Game 指标的相关性最强的是 40 码冲刺速度（所有 P ≤ 0.0001，部分 R > 0.3）。练习中 HIE 指标之间唯一显著的关系是穿梭跑速度与总练习撞击次数和 RWELinear-Practices、40 码冲刺速度与总撞击次数、三锥速度与 95%撞击次数/练习之间的关系。
一般来说，较高的垂直跳跃高度和速度和敏捷性训练中较快的时间与较高的 HIE 相关，尤其是在比赛中。在练习中，身体表现对 HIE 的变化解释较少，在练习中，训练和其他因素（例如教练风格）可能对 HIE 有更大的影响。
