Guinea pigs may be used to obtain insight into the nature of impact effects with much the same justification that small models of vehicles may be employed in stress analyses. White's group (4) has found that tolerance to impact of animals dropped in prone positions is almost linearly related to the mass of the animals and independent of the species. Other evidence shows the similarities of impact physiology (1) and pathology (1, 4) in different species of various sizes. An outstanding advantage in using small animals is that a greater number of exposure may be obtained economically and statistically significant data acquired.

In this paper some of the factors involved in transverse impact tolerance and pathophysiology have been investigated. In the experiments the magnitude and character of the forces;​ and, orientation and method of containment of animals have been carefully regulated. Analyses of transverse impact effects are particularly important because the forces are much better tolerated in these orientations (2) and offer the greatest opportunities for improvement in protection.