An ergonomical seat assembly for supporting a seated human body in correct posture to maintain proper and healthy spine, hip, and pelvic alignment. The seat assembly includes a back panel for supporting the back of a user in an upright sitting position and side support members for engaging the sides of the user's torso. Included is a lumbar support member for engaging the lower back of the user just above the hips. The back panel is secured to a base panel upon which is arranged hip support members for engaging the seated user's hips. Together the elements of the seat assembly maintain proper and healthy posture of a seated user and comfortable long or short term seating.