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 whiplash-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 after 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, with cervical symptoms and headaches predominating. Objective clinical deficits consistent with WAD were measured in both men and women subjects at both 4km/h and 8km/h. At 4km/h, the duration of symptoms experienced by women was significantly longer when compared with that in men (p < .05), There were no significant differences in the presence and severity of WAD between men and women at 4km/h and 8km/h or in the duration of WAD at 8km/h. There was also no significant difference in the presence, severity, and duration of WAD between 4km/h and 8km/h. No preimpact measures were predictive of WAD. Conclusion: The empirical findings in this study contribute to establishing a causal relationship between rear-end collisions and clinical signs and symptoms. (C) 1998 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.