. Hi Michael, you are correct with all your analyses, except for the machine resembling a cross country skiing motion. The motion is this. Standing leg extension of the quad. It will be accomplished by bending one leg, while standing up. That leg will have a foot roller in on the toe of the shoe and two shin pads sandwiching the shin. At this point, the individual will extend/ push the lever forward do that the leg is in a fully straight position at the climax of the movement. Think of the leg swinging from a bent position to a straight position.
chaniago, yes that is correct. Square not circular.
marcela1