This paper describes two motion simulators and their application to research in whole-body vibration. One is a four-degree-of-freedom device capable of producing vertical, pitch, roll, and yaw motions. The other is a single-degree-of-freedom device that produces motion in the horizontal direction. Both have been used to acquire information on whole-body and visual response to vibration. Frequency response plots of some of the acquired data are presented. Procedures for assessing the severity of human vibration responses in terms of absorbed power are described and discussed. Brief descriptions are presented of studies that made use of the equipment and methodology dicusssed. The first is a concept evaluation of a proposed vehicle for use on the lunar surface. The second is a hardware evaluation of two seating devices for use in a wheeled vehicle in severe terrain environment.