Instructions
Position a swiss ball against a wall and place the hollow of your back against the ball. Bring your legs out in front of you on a slight angle so that your body is leaning against the ball and place your hands on your hips. Place your feet approximately shoulder width apart and your feet out at a slight angle. Keeping your eyes up and knees flared, squat down by bending at the knees and bringing your hips back and down so that you are pushing your glutes back in towards the ball. Descend until your thighs are parallel to the floor. Hold this position and now focus on bringing your knees closer together, then pushing them out. Repeat for desired repetitions.
Tips
Make sure you do not push your legs upwards when moving your knees in and out. Keep your thighs parallel to the floor.