The monitor measures the accelerations and decelerations of the body and analyzes the results. On cardiotocography (CTG), umbilical cord compression can present with variable decelerations in fetal heart rate. Major decelerations can result in major vascular injuries near the kidney's hilum. "Decelerations" 3 and 4 are rumored to be released sometime in the future. If the rider moves his weight back and down, even larger decelerations are possible.