Despite improvements in seat design over the last decade for rear‐impact crash scenarios, the burden for insurance companies seemed to be so high that in several EU countries the legislation concerning claims for whiplash injury has recently been made more stringent. Many studies have been performed in an attempt to understand the injury mechanisms involved. This resulted in scientific publications of several different theories about the injury mechanisms and injury criteria. In this study a simulation method was developed for whiplash injury prediction that takes into account injury criteria covering several whiplash injury mechanisms by using an active human model. Two passenger car seats were modelled and validated on component level as well as against BioRID II sled tests under various loading conditions. In order to test the sensitivity of the developed simulation method rear‐impact simulations were performed with the active human model in conditions where parameters known to affect the whiplash injury risk were varied. Here, for each condition simulated the injury criterion showing the highest injury risk was assumed to give the overall injury risk on WAD2+. The developed simulation method showed similar effects on the risk of whiplash as known factors found in literature. Therefore, it was concluded that this simulation method can be used to further optimise whiplash assessment procedures and passenger seat designs for a more robust protection in the large range of real world rear‐impact accidents.