Abstract: A vehicle seat includes a seat bottom, a seat back pivotally connected with respect to the seat bottom, a seat track and an oscillating damped energy management device secured between the seat back and the seat bottom. The device includes a damper mechanism having a gear assembly coupled to a damper crank on a secondary gear shaft. Rotation of the damper crank causes an oscillating movement of a damper rod coupled to a damper cylinder. The viscosity of the fluid within the damper cylinder can be selected to vary the energy dampening characteristics of the damper mechanism. The damper mechanism may also include a pair of damper cylinders that can oscillate approximately ninety degrees out of phase with respect to each other to more smoothly control the damped energy during low and high impacts.