A lower-leg orthosis includes a splint for immobilizing the muscles of the lower leg. The splint comprises a lower-leg cuff and of a foot rest connected to the lower-leg cuff. A foot device is arranged under the foot rest, and the foot rest is supported on the ground via this foot device. The foot device has a ground contact surface and an elastic energy reservoir, which is arranged between the foot rest and the ground contact surface. Torques can be transferred from the foot rest surface to the ground contact surface via the foot device.