a School of Aviation , University of New South Wales , Sydney , Australia.
Traffic Inj Prev. 2015;16:268-75. doi: 10.1080/15389588.2014.931948. Epub 2014 Nov 10.
One of the main requirements of a protective bicycle helmet is to provide and maintain adequate coverage to the head. A poorly fitting or fastened helmet may be displaced during normal use or even ejected during a crash. The aims of the current study were to identify factors that influence the size of helmet worn, identify factors that influence helmet position and adjustment, and examine the effects of helmet size worn and adjustment on helmet stability.
Recreational and commuter cyclists in Sydney were surveyed to determine how helmet size and/or adjustment affected helmet stability in the real world. Anthropometric characteristics of the head were measured and, to assess helmet stability, a test analogous to the requirements of the Australian bicycle helmet standard was undertaken.
Two hundred sixty-seven cyclists were recruited across all age groups and 91% wore an AS/NZS 2063-compliant helmet. The main ethnic group was Europeans (71%) followed by Asians (18%). The circumferences of the cyclists' heads matched well the circumference of the relevant ISO headform for the chosen helmet size, but the head shapes differed with respect to ISO headforms. Age and gender were associated with wearing an incorrectly sized helmet and helmet adjustment. Older males (>55 years) were most likely to wear an incorrectly sized helmet. Adult males in the 35-54 year age group were most likely to wear a correctly adjusted helmet. Using quasistatic helmet stability tests, it was found that the correctness of adjustment, rather than size, head dimensions, or shape, significantly affected helmet stability in all test directions.
Bicycle helmets worn by recreational and commuter cyclists are often the wrong size and are often worn and adjusted incorrectly, especially in children and young people. Cyclists need to be encouraged to adjust their helmets correctly. Current headforms used in standards testing may not be representative of cyclists' head shapes. This may create challenges to helmet suppliers if on one hand they optimize the helmet to meet tests on ISO-related headforms while on the other seeking to offer greater range of sizes.
自行车头盔的主要要求之一是为头部提供和保持足够的覆盖。不合适或固定不牢的头盔在正常使用过程中可能会移位，甚至在碰撞中脱落。本研究的目的是确定影响头盔佩戴尺寸的因素，确定影响头盔位置和调整的因素，并检查头盔佩戴尺寸和调整对头盔稳定性的影响。
对悉尼的休闲和通勤自行车手进行了调查，以确定头盔尺寸和/或调整如何影响现实世界中头盔的稳定性。测量头部的人体测量特征，并进行类似于澳大利亚自行车头盔标准要求的测试，以评估头盔稳定性。
在所有年龄段共招募了 267 名自行车手，其中 91%的人佩戴符合 AS/NZS 2063 标准的头盔。主要种族群体是欧洲人（71%），其次是亚洲人（18%）。自行车手头部的周长与所选头盔尺寸的相关 ISO 头模周长非常匹配，但头部形状与 ISO 头模不同。年龄和性别与佩戴不合适尺寸的头盔和头盔调整有关。年龄较大的男性（>55 岁）最有可能佩戴不合适尺寸的头盔。35-54 岁年龄组的成年男性最有可能佩戴调整正确的头盔。使用准静态头盔稳定性测试发现，调整的正确性，而不是尺寸、头部尺寸或形状，显著影响了所有测试方向的头盔稳定性。
休闲和通勤自行车手佩戴的自行车头盔往往尺寸不合适，而且经常佩戴和调整不正确，尤其是在儿童和年轻人中。需要鼓励自行车手正确调整头盔。目前标准测试中使用的头模可能无法代表自行车手的头型。如果一方面头盔供应商优化头盔以满足 ISO 相关头模测试，另一方面又寻求提供更大的尺寸范围，这可能会给他们带来挑战。
