A damping device, which is provided between a handle and pole tube of a sport pole such as a ski pole, combines the action of a helical compression spring with that of a gas compression spring, whereby a rod-shaped body can be displaced inside a tube. A feed point is disposed along the horizontal axis on a first side of the vertical axis and a ground strip is disposed along the horizontal axis on a second side of the vertical axis opposite the feed point. When the base member is mounted on the engine, the ribs of one of the corrugated faces are fitted in the ridges of a corresponding corrugated face. The motor is fixed to the supporting portion.