A universal leg brace system for controlling the degree of motion permitted by a wearer's knee characterized by respective flexible sheets of cushioned material adapted for snugly wrapping around the wearer's thigh and calf; elongate braces that are stiff and adapted to lie on opposite sides of the wearer's thigh connected with a hinge positioned on opposite sides of the wearer's knee; rear stays connected with the respective sheets for providing structural support in the longitudinal direction longitudinally of the posterior of the thigh and calf; tibial and femoral plates connected with the first and second flexible sheets for providing significant structual support in the longitudinal direction along the anterior portion of the tibia and femur; straps and Velcro for adjustably positioning and selectively attaching the respective braces, sheets, plates and the like by circumferentially encompassing the leg of the wearer to provide significant longitudinal support without the requirement for a heavy, relatively permanent cast or the like.