Neck pain and head restraint position relative to the driver's head in rear-end collisions

This two-year investigation was designed to estimate the incidence of drive r neck pain in rear-struck vehicles involved in two-vehicle collisions and to determine the relationship between neck pain and specific vehicle, human , and environmental factors. Neck pain percentages were significantly highe r for female (45%) than for male (28%) drivers. For female and male drivers , neck pain likelihood increased as head restraint height decreased below t he head's center of gravity, although this effect was significant only for females. Head restraint backset, the horizontal distance measured from the back of the driver's head to the front of the head restraint, was not found to be related to neck pain for female drivers. Backset trends for male dri vers could not be evaluated because few male drivers had head restraints th at were high enough for backset to be relevant. Reported neck pain decrease d for older drivers (females only), drivers in less severe crashes, and dri vers in heavier cars (females only); all head restraint analyses were adjus ted for these characteristics. Women, and most likely men, in the United St ates would benefit greatly from international harmonization to European hea d restraint standards. Until then, both women and men should be encouraged to adjust their adjustable head restraints, if possible, behind their heads ' centers of gravity and to sit with the backs of their heads as close as p ossible to their head restraints. (C) 2000 Elsevier Science Ltd. All rights reserved.