NHTSA has collected a series of rear seat occupant data from full-scale frontal vehicle tests. The data set encompasses Research and Development and New Car Assessment Program (NCAP) tests and a variety of dummies, including adults and children in child restraint systems. This paper examines the effect of the cushion characteristics (shape, stiffness, thickness) and crash pulse on a small adult and a child in a forward facing child restraint (CRS) using sled tests. A controlled dynamic test will help us better understand how these factors influence the CRS crash dynamics. The thickness of the cushions had the most effect on dummy injury assessment values (IAV). The crash pulse characterization Vehicle Pulse Index (VPI) was the best predictor for head and chest injuries in such occupants.