Williams M
Technisearch Limited, Royal Melbourne Institute of Technology, Australia.
Accid Anal Prev. 1991 Apr-Jun;23(2-3):119-31. doi: 10.1016/0001-4575(91)90043-5.
A study of the injuries sustained by 1,892 bicycle riders during accidents indicated that 432 of the bicyclists had been wearing a helmet and 64 of the latter group had sustained an impact to the helmet. The 64 helmets were evaluated in this project to relate the nature and severity of the impact they had sustained to the head injury experienced by the wearer. The protective performance of the helmet shells, impact absorbing liners, and retention systems were evaluated, and the severity of the impacts sustained by the helmets was simulated in the test laboratory. The simulation was performed by dropping sample helmets from progressively greater heights in a test apparatus until the damage observed on a sample helmet matched that observed on an accident damaged helmet. The severity observed in the simulated impacts was compared with the severity of test impacts prescribed in established helmet performance standards (ANSI 1984; Snell 1984; AS 1986). It was found that all of the impacts occurred against flat objects; a high proportion of helmets sustained more than one impact; most impacts occurred on areas of a helmet which were not tested during certification to a standard; and many impacts were more severe than those stipulated in performance standards. The predominant form of head injury recorded was low severity concussion--AIS-1, AIS-2, AIS-3. All serious head injuries occurred when the helmet came off the rider's head and collapsed due to a material defect or was struck predominantly below the rim. A high proportion of helmets worn by young riders had been misused, and many helmets displayed defects in the impact-absorbing liners. Recommendations have been made for improving helmet construction and altering current standards to reflect the conditions encountered in the field.
一项针对1892名自行车骑行者在事故中所受伤害的研究表明，其中432名骑行者佩戴了头盔，而这一组中有64人的头盔受到了撞击。本项目对这64顶头盔进行了评估，以将其所受撞击的性质和严重程度与佩戴者所经历的头部损伤联系起来。对头盔外壳、冲击吸收衬里和固定系统的防护性能进行了评估，并在测试实验室模拟了头盔所受撞击的严重程度。模拟过程是在测试设备中从逐渐增加的高度掉落样品头盔，直到样品头盔上观察到的损坏与事故损坏头盔上观察到的损坏相匹配。将模拟撞击中观察到的严重程度与既定头盔性能标准（ANSI 1984；Snell 1984；AS 1986）规定的测试撞击严重程度进行比较。结果发现，所有撞击均发生在平坦物体上；很大一部分头盔受到了不止一次撞击；大多数撞击发生在头盔经标准认证测试时未测试的区域；而且许多撞击比性能标准规定的更为严重。记录的主要头部损伤形式为低严重程度的脑震荡——AIS-1、AIS-2、AIS-3。所有严重头部损伤均发生在头盔从骑行者头上脱落并因材料缺陷而坍塌或主要在边缘下方受到撞击时。年轻骑行者佩戴的很大一部分头盔被滥用，而且许多头盔的冲击吸收衬里存在缺陷。已就改进头盔结构和改变现行标准以反映实际使用中遇到的情况提出了建议。
