An in-depth study of neck injurlee in rear end collisions was made in order to investigate the severity of the injuries and the injury mechanisms in correlation with occupant and vehicle parameters.

The study inclued 33 occupants and their vehciles involved in 26 read end collisions. Extensive interviews and technical examinations were made as soon as possible after the accident. Medical examinations were made at this time and a year later.

No servere injuries according to the AIS classification were noted. However, various degrees of neck injury-related discomfort were noted in all but four cases. Prolonged discomfort, lasting more than 3 months, was noted for about 40 per cent of all occupants who had neck symptoms after the accident.

The duration of the neck symptoms was related to the estimated horizontal distance between the head and the head restraint at the time of the accident and, to some extent, to the deformation of the occupant's car in cases where any side beam was deformed.