How to do them: Start by placing two chairs facing each other, sit in one and place one foot on the other. Now straighten that leg and lift your foot 4-6 inches off of the chair and hold for a minimum of 5-10 seconds and then relax. Perform this exercise 5-10 times for each leg and try to extend the time you hold your foot off the chair.
Variations: If chairs are not available, you can perform this exercise flat on the floor with one leg straight and opposite leg bent with your foot flat on the floor. As you become stronger, you can add an ankle weight to increase the difficulty.