When using the knee CPM, make sure your foot is flat against the foot plate and your knee cap is aligned with the two hinges on the side. Your now going to secure the two straps. To use the controller, hit menu at the top of the controller. The far left button controls knee extension with plus or minus. The far right button controls knee flexion with plus or minus. Once your numbers are set, hit start, and the machine will move your knee for you.