a vehicle seat lumbar support adjustment device includes an actuator operatively connected to a cable which extends across the seatback . a compressible plastic support structure is positioned between the cable and a cushion layer , and movable toward the cushion layer by actuation of the cable in order to adjust lumbar support for a seat occupant . preferably , the compressible plastic support structure includes an integrally molded spring component positioned between opposing walls of the support structure .