This paper presents the development and validation of a 50th percentile male multi-body head-and-neck model, aimed primarily at analysing rear impact and the resulting whiplash injury effects. The objective is to design a computationally efficient model behaving like a human head and neck in the case of a rear impact. The volunteer sled tests performed by the Japanese Automobile Research Institute (JARI) have been used for the validation of the head-neck model for low-speed rear-impact analysis. The presented approach for the multi-body head-and-neck model is simple, effective, and capable of producing biofidelic responses. The results show that the model can represent with a high degree of accuracy the rear-impact response of a human.