Abstract: A portable folding orthopedic seat unit for use on a chair, automobile seat, or the like. A seat member is hinged to a back member. Vertical tracks extend from the bottom to the top of the back member and support a back-support assembly, comprising two separate, generally elliptically-shaped, centrally extending padded back-support members, spaced apart from each other, and a connecting member joining them together. The connecting member also serves to transfer forces from one back-support member to the other. Two strips that adhere to each other on contact are used to hold the assembly at a selected vertical position on the tracks.