A stage panel support assembly including four corner stanchions or posts permanently cross braced in one transverse direction and connected in a longitudinal direction by double jointed arms centrally pivoted at an apex on a base frame upright. A cross brace joins respective arms at points spaced from the apex. The corner stanchions are movable from a storage position above the base frame to the operative position spaced from the base and in a vertical position relative to a supporting surface. Projections at the top of the stanchions cooperate with removable horizontal panels which further stabilize the structure in operative position.