A materials handling vehicle is provided comprising: a frame; a set of wheels supported on the frame to allow the materials handling vehicle to move across a floor surface; a rider compartment located within the frame for receiving an operator; and an operator support assembly. The operator support assembly comprises a suspended floorboard upon which the operator may stand when located within the rider compartment and an energy absorbing structure coupled to the frame and the suspended floorboard for absorbing and dissipating at least a portion of energy resulting from disturbances encountered by the vehicle as it moves across the floor surface prior to the energy portion reaching the operator standing on the suspended floorboard, the energy absorbing structure including a damping element comprising a valve for effecting a damping function.