Abstract: A seating support for independent, multi-planar adjustable thoracic and pelvic-sacral cushions for supporting the spine and permitting support adjustment by the seated occupant. The thoracic support cushion is inflatably adjustable in a horizontal plane and vertically adjustable relative to apertured slide rails of a support framework. The pelvic-sacral support cushion vertically slide adjusts along the framework and is horizontally adjustable via a screw follower mounted scissors assembly having a laterally and tiltably rotatable cushion mounting plate. In an accessory embodiment, an adjustable clamp retainer and strap secure the support to an available rigid-backed chair.