The invention relates to a device comprising a detection unit (1) for the position and orientation of a first limb of a user (3) and a display device (4) for displaying a second limb (5). In order to design a device of the type described above so as to expand the range of motion for the two limbs of the user and at the same time allow interaction between the two limbs and between one of the limbs and a virtual three-dimensional object, it is proposed that the display device is designed stereoscopically and has, with the detection unit, a common reference plane as a reference system, in that, for display via the stereoscopic display device, a first generator is provided for a virtual second limb which is mirrored about the reference plane with respect to the position and orientation of the first limb, and a second generator is provided for a three-dimensional interaction object for display at a predetermined position and orientation with respect to the reference plane, and in that the device has a collision detection unit for outputting a signal upon detection of a collision between the virtual second limb and the virtual three-dimensional interaction object.
