Influence of the seat and head rest stiffness on the risk of cervical injuries in rear impact.

This study discusses the solutions to guarantee adequate protection against cervical injury in a rear impact with a stiffened seat, while still ensuring the higher restraint effectiveness required in a frontal impact. The study consists of: (1) an accident study into frequency and severity of injuries to occupants in rear impact accidents; (2) a definition of the accident conditions to be duplicated in which the greatest risk of cervical injury occurs; (3) tests carried out using the Hybrid III dummy; (4) Hybrid III dummy response limitations; and (5) recommendations for obtaining adequate protection in current and future vehicle models.