Abstract: A kinetic rehabilitation device employing controlled passive motion for use in the rehabilitation of the lumbar spine. The device includes a frame, a body support secured to the frame, a control panel, a first and second member secured to the support and pivotally attached to diametrically opposed sides of the frame, and a screw drive assembly for pivoting the first and second members about said frame. A first optical sensor assembly is mounted on one of the pivoting members to zero the body support about its longitudinal axis. A second optical assembly is mounted on the screw drive assembly to feed positional information to the control panel.