A backrest for supporting the back of a seated person, intended and adapted to form part of an article of seating furniture, such as a wheelchair, has the feature that the backrest consists of two parts, that is: a lower backrest part for supporting the sacral-lumbar part of the back of a seated person, and an upper backrest part for supporting the lumbar-thoracic part of the back of a seated person; both backrest parts can be moved independently of each other relative to the carrier; and a carrier therefor which has three degrees of freedom in a vertical plane, perpendicularly of the main plane of the backrests, relative to the frame tube, i.e. two degrees of freedom of translation corresponding to height and depth, and one degree of freedom of rotation around a horizontal rotation axis.