Low speed frontal crashes and low speed rear crashes: is there a differential risk for injury?

We compared male and female subjects in crash tests in which each subject experienced both frontal and rear impacts. Crash speed and other crash parameters were held constant. We believe this was the first experiment using an independent variable of crash vector and dependent variables of head linear acceleration and volunteer qualitative tolerance. Analysis of data revealed that the rear impact vector crash resulted in 2.8 times greater head linear acceleration than frontal crashes. Rear impact crashes resulted in biphasic, complex kinematics compared to the monophasic, less complex frontal crashes. Rear impact crashes were rated markedly less tolerable. Sex-specific differences are also discussed.