Pellman Elliot J, Viano David C, Tucker Andrew M, Casson Ira R
ProHealth Care Associates, LLP, Lake Success, New York, USA.
Neurosurgery. 2003 Dec;53(6):1328-40; discussion 1340-1. doi: 10.1227/01.neu.0000093499.20604.21.
National Football League game video was analyzed for the typical locations of severe helmet impacts in professional football. By use of selected cases that were reconstructed in laboratory tests and reported previously, the magnitude and direction of force causing concussion was determined for these locations.
Multiple video views were obtained for 182 severe helmet impacts that occurred between 1996 and 2001. From a top view, the helmet was divided into 45-degree quadrants with 0 degrees eyes forward. From a side view, it was divided into seven equal levels, four (+Q1 to +Q4) above the head center of gravity and three below (-Q1 to -Q3). The initial helmet contact was located in these regions. Thirty-one impacts were reconstructed with helmeted Hybrid III dummies involving 25 concussions. Measurement of head translational and rotational acceleration was used to determine the average and +/-1 standard deviation in responses, with impacts reflected to the right side.
From video, the majority (71%) of impact is to the helmet shell primarily from a striking player's helmet, arm, or shoulder pad to the side (45-135 degrees) or from ground contact to the back (135-180 degrees). Most impacts were high on the helmet at +Q2 to +Q4. The remainder (29%) were primarily from helmet contact on the facemask at an oblique frontal angle (0-45 degrees) and -Q3 to +Q1 height. From reconstructions, concussion occurred with the lowest peak head acceleration in facemask impacts at 78 +/- 18 g versus an average 107 to 117 g for impacts on other quadrants (t = 2.90, P < 0.005). There was a significantly higher head acceleration for concussed versus nonconcussed players (t = 2.85, P < 0.05). The vector of peak force was essentially horizontal for facemask impacts and downward at 12 to 27 degrees for impacts to the helmet side and back. Concussion in professional football involves four typical conditions, as follows: A, 0- to 45-degree quadrant, -Q3 to +Q3 level, peak force 49 +/- 18 degrees from front and horizontal; B, 45- to 90-degree quadrant, -Q2 to +Q3 level, peak force 73 +/- 12 degrees and horizontal; C, 90- to 135-degree quadrant, +Q1 to +Q4 level, peak force 97 +/- 9 degrees and 12 degrees downward; and D, 135- to 180-degree quadrant, +Q1 to +Q4 level, peak force 157 +/- 1 degrees and 27 degrees downward. Concussed players averaged 3.6 +/- 2.7 initial signs and symptoms. The most common were headaches, dizziness, immediate recall problems, and difficulty with information processing.
The location, direction, and severity of helmet impacts causing concussion in the National Football League have been defined from analysis of game video and laboratory reconstruction. These conditions define the circumstances in which helmets need to reduce head injury risks in professional football.
分析美国国家橄榄球联盟（National Football League）比赛视频，以确定职业橄榄球运动中头盔严重撞击的典型位置。通过使用先前报道的在实验室测试中重建的选定案例，确定这些位置导致脑震荡的力的大小和方向。
获取了1996年至2001年间发生的182次头盔严重撞击的多个视频视图。从俯视图看，头盔以眼睛向前为0度被划分为45度象限。从侧视图看，它被分为七个相等的级别，四个（+Q1至+Q4）在头部重心上方，三个在下方（-Q1至-Q3）。最初的头盔接触点位于这些区域。使用佩戴头盔的Hybrid III人体模型对31次撞击进行了重建，其中涉及25次脑震荡。通过测量头部平移和旋转加速度来确定反应的平均值和±1标准差，并将撞击反应换算到右侧。
从视频来看，大多数（71%）撞击发生在头盔外壳，主要是一名撞击球员的头盔、手臂或肩垫撞击到侧面（45 - 135度），或者因与地面接触撞击到背部（135 - 180度）。大多数撞击发生在头盔较高位置的+Q2至+Q4处。其余（29%）主要是面罩在斜向前角度（0 - 45度）以及-Q3至+Q1高度处受到头盔撞击。通过重建发现，面罩撞击导致脑震荡时头部加速度峰值最低，为78±18g，而其他象限撞击时平均为107至117g（t = 2.90，P < 0.005）。脑震荡球员的头部加速度明显高于未发生脑震荡的球员（t = 2.85，P < 0.05）。面罩撞击时峰值力向量基本为水平方向，而头盔侧面和背部撞击时向下呈12至27度。职业橄榄球运动中的脑震荡涉及四种典型情况，如下：A，0至45度象限，-Q3至+Q3级别，峰值力与前方呈49±18度且为水平方向；B，45至90度象限，-Q2至+Q3级别，峰值力与水平方向呈73±12度；C，90至135度象限，+Q1至+Q4级别，峰值力与水平方向呈97±9度且向下12度；D，135至180度象限，+Q1至+Q4级别，峰值力与水平方向呈157±1度且向下27度。脑震荡球员平均有3.6±2.7种初始体征和症状。最常见的是头痛、头晕、即时回忆问题以及信息处理困难。
通过对比赛视频和实验室重建的分析，已确定了美国国家橄榄球联盟中导致脑震荡的头盔撞击的位置、方向和严重程度。这些情况明确了职业橄榄球运动中头盔需要降低头部受伤风险的情形。
