When Do AIS 1 Neck Injuries Result in Long-Term Consequences? Vehicle and Human Factors

Abstract

AIS 1 neck injuries are the most frequent injury among car occupants in car collisions. The main public-health problem concerning neck injuries are those resulting in long-term consequences. Yet epidemiological studies mostly focus on data based on the initial injury outcome. This study compares the characteristics of rear impacts causing both short- and long-term consequences to the neck. Real life data from Swedish insurance material during 1990-1993 were used, where the resultant impact injuries to the neck were divided into two groups: occupants self-reporting initial symptoms shortly after the crash and a subgroup were the initial symptoms later developed into long-term consequences, estimated by medical specialists (chronic symptoms at least one year after the impact). The influence of change of velocity, crash pulse of the struck car, and the risk of long-term consequences to the neck in different car models, were evaluated. The relative risk of neck injury in terms of initial injury was strongly influenced by the mass ratio between the struck and the striking car while other parameters such as crash pulse seemed to be an influencing factor in crashes causing long-term consequences. Also, there was a 2.7 times higher risk of sustaining long-term consequences to the neck in a vehicle manufactured in the end of the 1980s or beginning of the 90s than in one manufactured in the beginning of 1980. If one of the main reasons for the increasing number of long-term disabling neck injuries is associated with the influence of crash-pulse and factors related to newer car models, the situation will gradually become worse as the older car fleet is replaced. There is an increasing need for effective preventive measures, based on long-term disability data.