Citation

VanKirk DJ. Proc. Am. Assoc. Automot. Med. Annu. Conf. 1969; 13: 165-184.

Copyright

(Copyright © 1969, Association for the Advancement of Automotive Medicine)

DOI

unavailable

PMID

unavailable

Abstract

During an accident or, more precisely, the "second collision," the driver and front seat passengers are violently subjected to impacts with the interior components of the vehicle. To describe accurately what exactly occurs during this collision has been the interest of research for many years. A typical example of what might occur to the unbelted right front passenger as a result of a 30 MPH frontal force accident may be described as follows: The right front passenger slides horizontally on the seat until his knees deform the structural metal which supports the glove box door. This impact usually causes contusions, abrasions, or even a fractured patella. The upper part of the torso then begins to rotate at the hips or jackknifes forward. If the instrument panel protrudes into the compartment far enough he will impact it with the lower thorax or chest. This will slow him down by absorbing some of his energy but it also starts the head-neck complex rotating about the thorax. His head continues its pendulum motion striking the header with a velocity equal to or in many cases greater than, the vehicle impact velocity. If the windshield is a pre-1966 model, the head penetrates both layers of glass and the plastic interlayer. In some cases this impact has been known to produce concussions. The occupant has now reached his maximum forward displacement and now must make a return trip back into the vehicle through the hole it made in the windshield. In doing so his head bobs up and down on the jagged lower edge of the hole, thus producing severe facial lacerations before settling back into the seat. All this action takes place in less than half a second.

The horrible experience an occupant undergoes when a vehicle is involved in an accident has been the constant reminder and the basis with which the automotive safety engineer has made contributions in the safety of modern motor vehicles. The largest single item which has reduced the severity of automobile impact injuries and, in many cases, has eliminated them completely is the lap belt restraint system.