Whiplash injury due to low severity vehicles crash is a global problem. The injury has long-term clinical and biomechanical implications. Since the mid-1960s, injury statistics have continuously revealed that females face a higher risk of suffering the injury category compare to males. Besides, in a frontal crash, the injury measures from the adult rear dummies were mainly higher than the same size dummies located in driver and front occupant seat. However, most regulations and user crash tests have focused on vehicle drivers and front-seat passenger due to high occupancy and mortality rates in the front seat. In this paper, mechanisms of whiplash injury were reviewed to contribute a further inclusive understanding of human impact reaction, variability quantification, validation, and prevention. The objective of this study is to develop a new design of head restraint (HR) for car rear occupants. In order to raise consideration whiplash injury and prevention mechanisms, impacts are simulated with computer modelling (Ls-Dyna simulation) and validated using Matlab. Therefore, a review of these injury mechanisms indicates the development of new anti-whiplash technology in the automotive safety area is necessary.