A rigid frame wheelchair of a box frame design includes a base frame which has a rear axle for receiving rear wheels and a left-hand side strut and a right-hand side strut for receiving steering wheels in the front regions of the side struts, an L-shaped seat-foot support frame having an L-shaped left-hand strut and an L-shaped right-hand strut, wherein each L-shaped strut has a seat tube segment and a foot support tube segment, and wherein the seat-foot support frame further has a transverse strut that connects the L-shaped struts, two coupling units that connect together in an articulated manner the base frame in the left-hand and right-hand front region to the seat-foot support frame in the region of the left-hand and right-hand foot support tube segments about an axis vertically to a sagittal plane for an angular adjustment, and wherein the foot support tube segments are adjustably mounted for a seat height adjustment, a left-hand frame connector and a right-hand frame connector, wherein the frame connectors fixedly connect together the base frame and the seat tube segments, and wherein the seat tube segments are configured to be connected to the frame connectors in various positions.In such a wheelchair the adjustment of the seat height and the seat angle is able to be carried out with low material use and reduced operating effort.
