The reformer was invented by Pilates founder Joseph Pilates. It is a bed-like frame with a flat platform on it, which rolls back and forth on wheels within the frame. The platform is attached to one end of the reformer by a set of springs. The springs provide choices of differing levels of resistance as the platform is pushed or pulled along the frame. The platform has shoulder blocks on it that keep practitioners from sliding off the end of the reformer as they push or pull the platform. Body weight and resistance of the springs are what make the platform more or less difficult to move. Reformers parts are adjustable for differing body sizes and different levels of skill.
