The effects of Whiplash Associated Disorder (WAD) from low speed rear-end collisions (REC) have been reported in the medical, scientific and engineering literature for several decades. Given the method of analysis, results have varied regarding the nature, onset and severity of spinal injury. While previously conducted laboratory crash tests have advanced the understanding of occupant dynamics from RECs, concern over investigative methodology and experimental artificiality remains.
The purpose of this study is to determine if any relationship existed between specific occupant characteristics, vehicular acceleration and the onset and severity of WAD. Ninety-five subjects involved in real world RECs are selected from an active database. Data is collected over an 18-month period. Fifty-nine subjects are females and 70% of the subjects are drivers. The subject's gender, age, height, weight, body mass index (BMI), vehicular acceleration (g), occupant seating position, level of restraint and impact duration is utilized as predictors for the onset and severity of WAD. Engineering analysis is conducted on each REC to determine the level of vehicular acceleration. A complete review of each subject's medical records is performed to confirm a diagnostic classification of WAD. Simulation of the mean height and weight of the male and female using actual crash pulse data is conducted using MADYMO (MAthematical DYnamic MOdel) [1].
A discriminant function analysis is performed, with occupant seating position as the only predictor variable that had significant discriminating power (P < 0.05). Interestingly, there are no statistically significant differences noted for BMI, gender, age, and level of restraint or vehicular acceleration. These findings also suggest that there is a need for further methodological refinement to distinguish the effects of WAD in RECs.