Abstract: An apparatus for pendulum motion for balancing at least one person or user in a plane, generally parallel to the ground, is characterized in that an extension for a footrest is carried by the suspension member further from the seat, and the extension of the suspension member is arranged in such a manner that, in the position of equilibrium of the apparatus, despite its connection to a suspension member remote from the seat in question, the footrest for the feet of the user of the seat is placed vertically downward of the means for pivotal connection of the suspension member closest to the seat in question.