Dynamic Responses of Female and Male Volunteers in Rear Impacts

Journal article, 2008

Objectives: Whiplash injuries from vehicle collisions are common and costly. These injuries most frequently occur as a result of a rear impact and, compared to males, females have up to twice the risk of whiplash-associated disorders (WAD) resulting from vehicle crashes. The present study focuses on the differences in the dynamic response corridors of males and females in low-severity rear impacts. Methods: In this study, analysis of data fromvolunteer tests of females frompreviously published data has been performed. Corridors for the average female response were generated based on 12 volunteers exposed to a change of velocity of 4 km/h and 9 volunteers exposed to a change of velocity of 8 km/h. These corridors were compared to corridors for the average male response that were previously generated based on 11 male volunteers exposed to the same test conditions. Results: Comparison between the male and female data showed that the maximum x-acceleration of the head for the females occurred on average 10 ms earlier and was 29% higher during the 4 km/h test and 12 ms earlier and 9% higher during the 8 km/h test. Head-to-head restraint contact for the females occurred 14 ms earlier at 4 km/h and 11 ms earlier at 8 km/h compared to the males. For the same initial head-to-head restraint distance, head restraint contact occurred 11 and 7 ms earlier for the females than the males at 4 and 8 km/h, respectively. Furthermore, the calculated Neck Injury Criteria (NIC) values were similar for males and females at 4 km/h, whereas they were lower for females compared to the males at 8 km/h (3.2 and 4.0 m2/s2, respectively). Conclusions: The results of this study highlight the need to further investigate the differences in dynamic responses between males and females at low-severity impacts. Such data are fundamental for the development of future computer models and dummies for crash safety assessment. These models can be used not only as a tool in the design and development process of protective systems but also in the process of further evaluation and development of injury criteria.