A second method that is useful in the open-chain position involves visualizing and feeling the subtalar joint as it moves through its range of motion.94 To begin, the examiner should place the ulnar surface of the thumb into the sulcus of the patient’s fourth and fifth toes, moving the patient’s foot from pronation to supination and back again. This movement is very similar in shape to that of a horse saddle, being very abrupt toward pronation and very flat and shallow toward supination (Fig. 16-28A). The bottom of this saddle is the neutral position of the subtalar joint. This can be confirmed visually by observing the lateral curves above and below the malleolus (Fig. 16-28B). If these curves are the same depth, this is the accurate neutral position. If the curve below the malleolus is deeper or shallower, then the foot is still in a pronated or supinated position and should be repositioned.