Head impact conditions in the case of cyclist falls

Abstract

In 2009 approximately half of the French population owned a bicycle. However, the cyclist’s accident rate is the highest of all road users. Hence, it is necessary to set up a protection system for cyclists, especially for the cephalic segment. Currently, relatively little literature has dealt with the head impact condition for this kind of accident, especially for cases of cyclist falls. Therefore, the objective of this work was to identify the initial conditions for head impact in cases of cycling fall accidents. The present paper proposes a parametric study by simulating a lot of accident scenarios. A total of 1024 simulations have been automatically carried out using Madymo®’s software and a specially designed program. Two situations of cycling falls have been investigated according to real accident configuration: cyclist falls due to skidding and after hitting a curb. The TNO (Dutch Organization for Applied Scientific Research, Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek) pedestrian 50th percentile human model was coupled to a city bicycle model. The analysed outputs are head impact area and head velocity before impact. The work has provided a solid information base for future work on cyclist accidents. The parametric analysis was also used to study the effects of poorly known environmental parameters, such as speed or torso inclination. The results provided estimates of the impact area and speed of the head, which helps to improve the design of safer helmets and of helmet certification standards tests.