Withnall C, Shewchenko N, Wonnacott M, Dvorak J
Biokinetics and Associates Ltd, Ontario, Canada.
Br J Sports Med. 2005 Aug;39 Suppl 1(Suppl 1):i40-8; discussion i48. doi: 10.1136/bjsm.2005.019174.
Commercial headgear is currently being used by football players of all ages and skill levels to provide protection from heading and direct impact. The clinical and biomechanical effectiveness of the headgear in attenuating these types of impact is not well defined or understood. This study was conducted to determine whether football headgear has an effect on head impact responses.
Controlled laboratory tests were conducted with a human volunteer and surrogate head/neck system. The impact attenuation of three commercial headgears during ball impact speeds of 6-30 m/s and in head to head contact with a closing speed of 2-5 m/s was quantified. The human subject, instrumented to measure linear and angular head accelerations, was exposed to low severity impacts during heading in the unprotected and protected states. High severity heading contact and head to head impacts were studied with a biofidelic surrogate headform instrumented to measure linear and angular head responses. Subject and surrogate responses were compared with published injury assessment functions associated with mild traumatic brain injury (MTBI).
For ball impacts, none of the headgear provided attenuation over the full range of impact speeds. Head responses with or without headgear were not significantly different (p>0.05) and remained well below levels associated with MTBI. In head to head impact tests the headgear provided an overall 33% reduction in impact response.
The football headgear models tested did not provide benefit during ball impact. This is probably because of the large amount of ball deformation relative to headband thickness. However, the headgear provided measurable benefit during head to head impacts.
目前,各年龄段和技能水平的足球运动员都在使用商业头盔,以防止头球和直接撞击带来的伤害。头盔在减轻这类撞击方面的临床和生物力学效果尚未得到明确界定或充分理解。本研究旨在确定足球头盔是否会对头部撞击反应产生影响。
使用一名人类志愿者和模拟头/颈系统进行了对照实验室测试。对三种商业头盔在6 - 30米/秒的球撞击速度下以及在2 - 5米/秒的头部对头部接触闭合速度下的撞击衰减情况进行了量化。配备了测量线性和角向头部加速度仪器的人类受试者,在未佩戴和佩戴头盔的状态下进行头球时,会受到低强度撞击。使用配备了测量线性和角向头部反应仪器的生物逼真模拟头模,研究了高强度头球接触和头部对头部撞击。将受试者和模拟头模的反应与已发表的与轻度创伤性脑损伤(MTBI)相关的损伤评估函数进行了比较。
对于球撞击,没有一种头盔在整个撞击速度范围内都能提供衰减。佩戴或不佩戴头盔时的头部反应没有显著差异(p>0.05),且仍远低于与MTBI相关的水平。在头部对头部撞击测试中,头盔使撞击反应总体降低了33%。
所测试的足球头盔型号在球撞击时没有提供益处。这可能是因为相对于头带厚度,球的变形量很大。然而,头盔在头部对头部撞击时提供了可测量的益处。