Abstract: A chair for providing support and corrective forces to a patient having scoliotic, lordotic or kyphotic conditions includes parallel side panels with parallel vertical slots on the inner faces and slats extending between the panels. The slats have end fittings which are selectably insertable in the slots with the bottom of each slat resting on the one below so that the slats define a generally curvilinear surface having predetermined curvatures. Devices for holding straps and pads to apply lateral forces in a predetermined manner are also provided. Specific slat structure and full adjustability is provided.