McIntosh A S, McCrory P
School of Safety Science, University of New South Wales, Sydney, Australia.
Br J Sports Med. 2000 Oct;34(5):337-41. doi: 10.1136/bjsm.34.5.337.
Commercially available football head protectors were tested to determine their impact energy attenuation performance and ability to reduce the likelihood of concussion.
Prospective study using standardised impact test methods with both rigid (magnesium) and Hybrid III headforms.
Eight commercially available head protectors from six manufacturers were tested. The magnitude of the headform accelerations increased as the drop height was increased, ranging from a minimum of 64 g from a height of 0.2 m to a maximum of 1,132 g from a height of 0.6 m. The head injury criterion and maximum headform acceleration values followed a similar trend. A steep increase was noted in the magnitude of maximum headform acceleration and head injury criterion when the drop height was increased from 0.4 to 0.5 m. This indicates that the foam material was completely compressed at an impact energy above about 20 J and therefore offers little protection against impacts of greater severity. Repeated tests using a drop height of 0.3 m showed that some helmets exhibit a "memory" effect, whereby impact performance is reduced by up to 50% with repeated impacts.
Laboratory tests indicate that current commercially available football headgear performance will not reduce the likelihood of concussion. The absence of internationally recognised standards for soft headgear designed to ameliorate concussion is a major deficiency in sports injury prevention.
对市售的橄榄球头盔进行测试,以确定其冲击能量衰减性能以及降低脑震荡可能性的能力。
采用前瞻性研究,使用标准化冲击测试方法,分别对刚性(镁质)和混合III型头模进行测试。
对来自六个制造商的八种市售头盔进行了测试。随着下落高度增加,头模加速度的幅度也增加,范围从0.2米高度时的最低64g到0.6米高度时的最高1132g。头部损伤标准和最大头模加速度值呈现类似趋势。当下落高度从0.4米增加到0.5米时,最大头模加速度和头部损伤标准的幅度急剧增加。这表明泡沫材料在冲击能量高于约20J时完全被压缩,因此对于更严重的冲击几乎没有防护作用。使用0.3米下落高度的重复测试表明,一些头盔呈现出“记忆”效应,即随着重复冲击,冲击性能降低高达50%。
实验室测试表明,目前市售的橄榄球头盔性能无法降低脑震荡的可能性。缺乏用于减轻脑震荡的软质头盔的国际认可标准是运动损伤预防中的一个主要缺陷。