A device for therapeutically treating and/or training the lower extremities of a person, having driven controllable motion devices connected to a stationary frame and retaining means for attaching to each extremity, that can be displaced independently along walking trajectories. Motion devices provide an outrigger pivotable to various height levels, jointedly connected at a first carriage of a linear guide on one side, and rotationally connected to a retaining means on the other side. A second carriage of the linear guide is disposed ahead of the first carriage and jointedly connected to the outrigger by means of a connecting element. The first carriage has a first linear drive for changing the longitudinal position of each retaining means, the second carriage providing a second linear drive for changing the height level of each retaining means. The outrigger provides a rotary drive for changing the slope of each retaining means.