An electrically-powered, air-inflated arrangement of cushions and supports intended to be attached to a chair (e.g., wheelchair, dining chair) to provide comfort, improve posture, and help prevent pressure sores for the occupant, who is typically a patient affected by neuromuscular dysfunction. The device is composed of different cushions (e.g., lumbar, pelvic) which are independently inflated/deflated by an attendant and/or the occupant via electronic controls; the device may feature automatic inflation/deflation with occupant movement.