CLINICAL-RESPONSE OF HUMAN-SUBJECTS TO REAR-END AUTOMOBILE COLLISIONS

Objective: Forty-two persons were exposed to controlled low-speed rear -end automobile collisions to assess the relation between both gender and impact severity and the presence, severity, and duration of whipla sh-associated disorders (WAD). Individual measures were also assessed for their potential to predict the onset of WAD. Design: Experimental study subjecting individuals to a speed change of 4km/h and 8km/h and utilizing pretest and posttest physical examinations (immediately afte r and 24 hours after impact) to quantify subjects' clinical response. Results: Approximately 29% and 38% of the subjects exposed to the 4km/ h and 8km/h speed changes, respectively, experienced WAD symptoms, wit h cervical symptoms and headaches predominating. Objective clinical de ficits consistent with WAD were measured in both men and women subject s at both 4km/h and 8km/h. At 4km/h, the duration of symptoms experien ced by women was significantly longer when compared with that in men ( p < .05), There were no significant differences in the presence and se verity of WAD between men and women at 4km/h and 8km/h or in the durat ion of WAD at 8km/h. There was also no significant difference in the p resence, severity, and duration of WAD between 4km/h and 8km/h. No pre impact measures were predictive of WAD. Conclusion: The empirical find ings in this study contribute to establishing a causal relationship be tween rear-end collisions and clinical signs and symptoms. (C) 1998 by the American Congress of Rehabilitation Medicine and the American Aca demy of Physical Medicine and Rehabilitation.