to one side of a vehicle seat back frame and its other end d connected to an actuator 110 mounted on the other side of the frame the support can be adjusted to increase or decrease respectively the level of lumbar support provided to an occupant of the seat operation with actuator 10 of fig1 to 10 can be similar however of course adjustment of an adjustable device by actuator 10 is by movement transmitted via the bowden cable system 16 the projections 104 may be formed integrally with part 144 of nut 132 however this would require that part d of the adjustable device is split to enable projections 104 to be received therein in the arrangement illustrated alternatively the projections 104 may comprise a respective or common pin bolt or the like separable from part 144 and securable in a lateral bore defined by part 144 after being inserted through part d such separable projection 104 may be securable in part 144 by screw threaded engagement in the lateral bore or by any other suitable means in a variant on the embodiment of fig1 the part 144 of nut 132 may have a lateral bore or oppositely opening lateral bores and not include projections such as shown at 104 with that variant each side s of end part d of an adjustable.