In this study indications of differences in motion pattern of females and males have been found. The objective was to quantify dynamic motion responses of female and male volunteers in rear impact tests. Such data can be used as an input in the development process of improved occupant models such as computational models and crash test dummies. High-speed video data from rear impact tests at 4 km/h and 8 km/h with 12 female and 11 male volunteers was analysed. The females in this study had smaller rearward horizontal and angular motions of the head and T1 compared to the males. Furthermore, the females had more pronounced rebound motion.