Abstract: Results relevant to the cushioning of impact by visco-elastic polyurethane (VEPU) and other foams were published by Saunders et al (Journal of Battlefield Technology, Vol. 15, No. 2, 2012, pp. 11-18). The present paper summarises some theory on how maximum acceleration might be affected by speed of impact, and uses it to comment on the results of Saunders et al. In the case of some foams at some speeds, it is likely that bottoming out occurred. There are several characteristics of foam deformation that potentially could be used to make bottoming out less likely: increased stiffness, nonlinear (concave downwards) response to deformation, and velocity-dependence of stiffness.