A lumbar support device for a vehicle seat permits vertical and fore-aft adjustment of the support or forces exerted on the back of an operator seated on the vehicle seat. The lumbar support device includes a lumbar panel resiliently flexibly attached to the seat frame and/or seat shell to permit fore and aft movement of the lumbar panel relative to the seat back, the lumbar panel arranged to bear against the seat back, and a cam element having a cam surface bearing against the lumbar panel to apply force to the lumbar panel toward the seat back, the cam element supported on the seat frame and/or seat shell for movement relative to the lumbar panel and relative to the seat shell and/or seat frame, the cam element configured to vary the force applied to the seat back based on the movement of the cam element.