Head, Hip and Knee Velocities of Restrained Occupants in Frontal Impacts

This study presents an efficient method for forensic engineers to determine the maximum forward head, hip and knee velocities of automobile occupants who are restrained by seat belts during frontal impacts. The ratios of the peak head, hip and knee velocities as a function of the impact speed change were determined from a combination of previous research data. The time and location at which the peak velocities occur are also presented. In addition, the head velocity profile as a function of head displacement was quantified for the lap and torso restraint case. The compiled head, hip and knee velocities may be utilized in order to assess seat belt usage and benefit. The results of this study may be referenced to aid in modeling the motion of vehicle occupants in frontal impacts for a range of impact severities.