Abstract: A suspension system has an isolator cylinder with a primary reservoir having a primary reservoir volume, a secondary reservoir having a secondary reservoir volume, a manifold and a primary duct fluidly connecting the primary and secondary reservoirs for controlling the flow rate of the fluid between the primary and secondary reservoirs, and optionally a valve for controlling a flow rate of a fluid through the duct, and a control system for operating the valve. A shock absorption system for a vehicle seat is provided comprising an isolator with at least one secondary pneumatic reservoir connected with a fluid duct to the primary reservoir of an isolator. The reservoir volumes, length and cross sectional area of the connecting duct and fluid flow control valves may be determined using methods including algorithms, experimental testing and models to determine the optimal values to achieve consistent shock mitigation across a range of seat loads.