The objective of this study was to compare head impact data acquired with an impact monitoring mouthguard (IMM) to the video-observed behavior of athletes’ post-collision relative to their pre-collision behaviors. A total of n = 83 college and high school American football players wore the IMM and were video-recorded over 260 athlete-exposures. Ex-athletes and clinicians reviewed the video in a two-step process and categorized abnormal post-collision behaviors according to previously published Obvious Performance Decrement (OPD) definitions. Engineers qualitatively reviewed datasets to check head impact and non-head impact signal frequency and magnitude. The ex-athlete reviewers identified 2305 head impacts and 16 potential OPD impacts, 13 of which were separately categorized as Likely-OPD impacts by the clinical reviewers. All 13 Likely-OPD impacts were in the top 1% of impacts measured by the IMM (ranges 40–100 g, 3.3–7.0 m/s and 35–118 J) and 12 of the 13 impacts (92%) were to the side or rear of the head. These findings require confirmation in a larger data set before proposing any type of OPD impact magnitude or direction threshold exists. However, OPD cases in this study compare favorably with previously published impact monitoring studies in high school and college American football players that looked for OPD signs, impact magnitude and direction. Our OPD findings also compare well with NFL reconstruction studies for ranges of concussion and sub-concussive impact magnitudes in side/rear collisions, as well as prior theory, analytical models and empirical research that suggest a directional sensitivity to brain injury exists for single high-energy impacts.

本研究的目的是将使用碰撞监测护齿器 (IMM) 获得的头部碰撞数据与运动员碰撞后相对于碰撞前行为的视频观察行为进行比较。共n = 83 名大学和高中美式橄榄球运动员佩戴 IMM 并录制了超过 260 名运动员的视频。前运动员和临床医生分两步查看视频，并根据先前发布的明显性能下降 (OPD) 定义对碰撞后异常行为进行分类。工程师对数据集进行定性审查，以检查头部撞击和非头部撞击信号的频率和幅度。前运动员审查员确定了 2305 次头部撞击和 16 次潜在 OPD 影响，其中 13 次被临床审查员单独归类为可能的 OPD 影响。所有 13 种可能的 OPD 影响都在 IMM 测量的影响中的前 1%（范围 40–100 g、3.3–7.0 m/s 和 35–118 J），13 种影响中有 12 种 (92%) 对头部的侧面或后方。在提出任何类型的 OPD 影响幅度或方向阈值存在之前，这些发现需要在更大的数据集中进行确认。然而，本研究中的 OPD 案例与之前发表的针对高中和大学美式橄榄球运动员的影响监测研究相比，后者寻找 OPD 迹象、影响程度和方向。我们的 OPD 发现也与 NFL 重建研究在侧面/后部碰撞中的脑震荡和次震荡影响幅度范围以及先前的理论、分析模型和实证研究进行了很好的比较，这些研究表明单个高能源影响。本研究中的 OPD 案例与之前发表的针对高中和大学美式橄榄球运动员的影响监测研究相比，后者寻找 OPD 迹象、影响程度和方向。我们的 OPD 发现也与 NFL 重建研究在侧面/后部碰撞中的脑震荡和次震荡影响幅度范围以及先前的理论、分析模型和实证研究进行了很好的比较，这些研究表明单个高能源影响。本研究中的 OPD 案例与之前发表的针对高中和大学美式橄榄球运动员的影响监测研究相比，后者寻找 OPD 迹象、影响程度和方向。我们的 OPD 发现也与 NFL 重建研究在侧面/后部碰撞中的脑震荡和次震荡影响幅度范围以及先前的理论、分析模型和实证研究进行了很好的比较，这些研究表明单个高能源影响。