to rail bracket 30 which is slidably attached to lateral rails 24 c in the embodiment described herein the support panel comprises grid 22 and grid 22 is pivotably attached to base wire 24 of which lateral rails 24 c form a part in a preferred embodiment grid 22 pivots at its top end 22 a fig1 base wire 24 can assume various configurations provided that base wire 24 comprises a pair of lateral rails 24 c and a means for securing these to seat back 60 in one embodiment base wire 24 also comprises an upper base wire 24 a portion and a lower base wire 24 b portion connected to lateral rails 24 c fig1 grid 22 comprises a frame 42 across which are attached a series of approximately parallel horizontal crosswires 44 frame 42 consists of two roughly parallel side portions joined by top and bottom portions it is crosswires 44 that primarily support the seat occupant 39 s back although in the lumbar region lift wire 26 may also contribute to supporting the occupant 39 s back depending on the particular design of lift wire 26 that is employed in one embodiment lift wire 26 is attached to a point closer to the bottom of grid 22 thereby giving greater support to the lumbar region of the occupant 39 s back pivot bracket 28 can be designed to attach to grid 22 in several different ways fig6 a 6d pivot bracket 28 can snap onto lift wire 26 and the border of grid 22 fig6 d or can alternatively be designed with a hole through which lift wire 26 and.