Abstract: A seat positioning device includes a swingable support pad secured to a hinge, which is secured to a wheelchair seat back via a hardware assembly. The hinge includes a frame bracket with primary and secondary flanges having a rotatable barrel secured therebetween. A lock plate locking flange, sized to be receivable within a barrel locking groove formed in one end of the barrel, is spring-biased into a locking aperture in the secondary flange and toward the barrel locking groove. The barrel can rotate until the locking flange, locking aperture, and locking groove are aligned and the locking flange is allowed to lock the hinge in position by entering the locking groove through the locking aperture. The hardware assembly is configured to position the hinge so as to minimize the extent to which the pad extends beyond the side of a wheelchair when the pad is in a stowed position.