The Prafo 650 APU ® is a totally Adjustable Posterior Upright design that provides the practitioner a more precise, simplified, and calibrated method of setting the optimal dorsi/plantarflexion angle. This setting of the optimal angle is done by simply loosening the two adjustment screws, repositioning and then retightening the screws. The Prafo 650 APU eliminates any pressure to the medial/lateral aspects of the malleoli that typically can be attributed to double-jointed systems.