This article reviews dynamic testing of 73 seat/head restraint combinations available in 63 car models in the US market, carried out by the Insurance Institute for Highway Safety. The ratings make part of an international programme. Many car models have head restraints with poor- or marginal-rated geometry. Seat/head restraints should support the seat occupant's neck and head to accelerate them with the torso as the vehicle is driven forward following a rear impact. Good geometry is necessary for a restraint but not sufficient alone to protect the head and neck. Dynamic tests were not conducted in the past becuase of lack of a test dummy with a realistic spine and neck configuration: the development of the BioRID dummy with improved seat geometry has led to the introduction of dynamic crash sled testing worldwide. Seats fail the test if the seat back rotates backwards in the impact. The best results came from Saab and Volvo models.
Abstract