Injury Symptom Risk Curves for Occupants Involved in Rear End Low Speed Motor Vehicle Collisions

A comprehensive analysis of published data from human volunteer testing and epidemiological data was performed to assess the likelihood of an occupant experiencing injury symptoms in a rear end motor vehicle collision of minimal severity. The analysis considered whether any lower grade Whiplash Associated Disorder (WAD) symptoms were reported without assessing whether an injury actually existed. WAD symptoms (Grade I and II) have been an area of great interest as a general consensus does not exist on the exact mechanism behind the injury and because they elude objective clinical diagnosis. The reviewed literature reported parameters from occupants involved in rear impact low speed motor vehicle collisions and included reported symptoms, symptom duration, delayed onset of symptoms, number of impacts sustained by each individual and the vehicle’s change in velocity (ΔV). The data reported were left and right censored (doubly censored) and the reported injury symptoms were statistically analyzed to produce injury symptom risk curves. Due to the wide variety of data sources, variations in test methods and data collected, some limitations were imposed on the resulting risk curves. This paper presents the resulting risk curves, their applicability, and their limitations.