Abstract: A skateboard has one or two standing surface extensions. The extension or extensions are mounted on the skateboard and dismounted therefrom by means of a tongue-groove principle to equip a skateboard having a pintail with a kicktail at the front and at the rear or optionally only at the front/rear or at the front and the rear.

Abstract: A device is used for carrying out movements by shifting the center of gravity and/or actuating muscles of a human body. A user lies on the device and shifts the center of gravity by moving his or her hip region in order to incline a movable part of the device including the user's own body in different directions. Furthermore, the user wears video goggles or the like during the process and can move in a virtual environment using the overall system, which includes the video goggles and the movement device and can interact with these. The movements caused by the user can be generated solely using gravity by shifting the center of gravity. Additionally, the movements of the device are influenced by motors or dampers arranged in or on the device.

Abstract: A skateboard has one or two standing surface extensions. The extension or extensions are mounted oil the skateboard and dismounted therefrom by means of a tongue-groove principle to equip a skateboard having a pintail with a kicktail at the front and at the rear or optionally only at the front/rear or at the front and the rear.

Abstract: A system and a method detect alignment of a movement machine in a cost-effective manner. An alignment sensor system includes a movement instrument (1) for carrying out movements by displacing the center of gravity or actuating the muscles of a human body, with an alignment element, and a mass produced sensor, which is fixed relative to the alignment element.