Piston

Starting in standing position and a Block/Coupon on the ground at your feet, squat and pick up block and return to standing position with it. Then perform a squat and place the block to it's original position and return to original standing position w/out the block. Uncoordinated pax 9most everyone) will eventually get out of sync thereby looking like the pistons of that "See-Thru" engine block you see at the car parts store.