Abstract: A medical appliance, having a thick foam core received within a cover made of fleece, for simultaneously treating spinal, shoulder girdle, head, neck and related conditions. The appliance includes a seat cushion surrounded on three sides by a three-sided vest having a back wall and a pair of forwardly extending side walls. Each side wall includes an inwardly projecting protuberance formed on its inner surface that bears against the patient's waistline for therapeutic purposes when a belt that circumscribes the back and side walls is tightened, and a similar protuberance is formed in each side wall at the bottom thereof to help center the patient's hips atop the cushion and to hold them against lateral displacement. The rigidity of a side wall is enhanced by selectively placing a rigid stay member in a slot formed in each side wall.