The present invention relates to a robotic system useful to unload an object/person from its weight. The robotic system is useful in locomotor rehabilitation programs and allows the manipulation of forces in a three-dimensional space with far lower actuator requirements and a much higher precision than prior-art systems. The apparatus combines passive and active elements to minimize actuation requirements while still keeping inertia to a minimum and control precision to a maximum. It requires minimal actuators and at the same time has a low inertia.