The first is that there are "points of measurement" to feel the alignment of your body. Your shoulders rest against shoulder pads and you place your feet on the foot bar. Instantly, you can feel your alignment or your instructor will be able to see it and correct you. The reformer is up off the ground, which makes it much easier for someone who is elderly or injured to get on and off. Many exercises are performed seated, to help with pelvic stabilization. There are weights to these exercises but since alignment and flexibility are key, most people are not challenged by the added weights.