A field and laboratory study of the performance of pedal cycle helmets in real accidents

McIntosh, A.; Dowdell, B.

Affiliations

¹Road Safety Bureau Crashlab, RTA, NSW, Australia

Abstract

A study of real pedal cycle accidents was undertaken in Sydney Australia over a four month period in early 199 1. Accidents of all severities in which helmets were worn were investigated. The sample sources were: accident and emergency departments, the police, the coroners courts and direct through advertising in cycling magazines and clubs. During the investigation; accident data, injury data, anthropometric data and the helmets were collected. The helmets were then examined in the laboratory for: resultant damage, impact location etc. Further, a matching helmet was tested in order to reproduce the observed damage and thus calculate the impact dynamics.

As compulsory helmet wearing for pedal cyclists became active from Jan. ’ 91 there was a fair response. A sample of 42 cases was finally examined. In this group there was a good mixture of age groups, accident types and helmet models ( hard shell, micro shell & soft shell ). Some of the results are: The most frequently impacted region of the helmet was the frontal/temporal area ( 67 % ). There was a higher incidence of head injury AIS > =2 resulting from impact to the temporal region. There were four fatalities, three with fatal head injuries. No skull fractures were observed with non-fatally injured helmeted cases. The most frequent injury was AIS 1 injuries to the upper or lower limbs. For the group of helmets in which damage reproduction was satisfactory, the max. resultant accelerations for all helmets were between 72 and 345g, mean non-head injury 129g., mean head injury 18Og. The impact velocities were between 12 and 20 km/h, mean 16.4 km/h and a mean weight corrected impact velocity of 20 km/h.

Nearly all the soft shell helmets, ie. Expanded Polystyrene, exhibited a great deal of material cracking including separation. In some cases the helmets were split into two halves or into multiple pieces. It was not possible to reproduce this damage with the test procedure.

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Cited By (7)

Year	Entry
1993	Smith TA, Tees D, Thom DR, Hurt HH Jr. Evaluation and replication of impact damage to bicycle helmets. In: 37th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). November 4-6, 1993; San Antonio, TX.143-155.
2003	Mills NJ, Gilchrist A. Reassessing bicycle helmet impact protection. In: Proceedings of the 2003 International IRCOBI Conference on the Biomechanics of Impact. September 25, 2003; Lisbon, Portugal.15-26.
1993	McIntosh AS, Kallieris D, Mattern R, Miltner E. Head and neck injury resulting from low velocity direct impact. In: Proceedings of the 37th Stapp Car Crash Conference. November 7-8, 1993; San Antonio, TX. Warrendale, PA: Society of Automotive Engineers:43-57. SAE 933112.
1995	McIntosh AS, Kallieris D, Mattern R, Svensson NL, Dowdell B. An evaluation of pedal cycle helmet performance requirements. In: Proceedings of the 39th Stapp Car Crash Conference. November 8-10, 1995; San Diego, CA. Warrendale, PA: Society of Automotive Engineers:111-119. SAE 952713.
2003	Maki T, Kajzer J, Mizuno K, Sekine Y. Comparative analysis of vehicle–bicyclist and vehicle–pedestrian accidents in Japan. Accid Anal Prev. November 2003;35(6):927-940.
2000	McIntosh AS, McCrory P, Comerford J. The dynamics of concussive head impacts in rugby and Australian rules football. Med Sci Sports Exer. December 2000;32(12):1980-1984.
1997	Smith TA. The Effect of Helmet Liner Density Upon Acceleration and Local Contact Forces During Bicycle Helmet Impacts [PhD thesis]. Los Angeles, CA: University of Southern California; December 1997.