Abstract: A lumbar support assembly for a seat having a seat frame and a backrest. The assembly (10) includes a rigid mounting member (18) within the seat frame (14) supported by a plurality of springs (28) or alternatively by integral clips (58). A pneumatic bladder (32) is supported on the mounting member (18) by a plurality of fasteners (61). A contoured plate (42) is disposed adjacent the mounting member (18) and the bladder (32) is supported between the contoured plate (42) and the mounting member (18), as the bowed contoured plate (42) urges the bladder (32) toward the inflated position. A plurality of guides (30) are disposed upon the mounting member (18) and are adapted to slideably receive a plurality of fingers (56) integrally disposed on the contoured plate (42). A pneumatic tube (34) extends from the bladder (32) to a normally closed pneumatic control valve (36) which is attached to any remote location.