Kneel down facing a wall.
Place the foot you would like to exercise in front of you and place your palms on the wall.
Start with your toes touching the wall.
Move your hips towards the wall, allowing your knee to travel forward and touch the wall.
If you are able to do this without your heel lifting, slide your foot back a little, and repeat.
Once you reach the point that your heel starts to lift from the floor before your knee touches the wall, hold your foot in this position, and rock your hips forward and backward.
Continue for the stated period of time or repetitions.