… using a stair or a low sturdy bench, step up and step down, first with one leg, then the other. An aerobic step, which can be purchased at most sporting goods stores, is perfect for this exercise.
3. Ankles:
Sit on the floor for the ankle strengthening exercises. Grab a towel at each end and place your foot in the middle, keeping your leg straight. Hold the towel ends tightly and press your foot forward while pulling back on the towel. Turn your foot to each side and press hard against the towel. Use enough force so that your ankle joint has to really work.