A slider-crank mechanism whose coupler curve is the approximate ellipse is designed so that a man may perform the pedaling of the elliptical motion of the foot. Because the thigh. the shank and the foot constitute the three-link chain. the system of a man and the bicycle with the slider-crank pedal mechanism is the planar seven-link mechanism with two degree freedom. https://www.spidertattooz.com/The-GelBottle-Inc-Gel-Polish-Audrey-67oz-p17921/