Stand with you back against a wall with feet about two feet away from the wall hip- or shoulder-width apart.
2. Contract the abs and keep them tight as you bend the knees and slowly squat (move your butt) towards the ground.
Keep the knees behind the toes as you move into a position like you are sitting in an invisible chair. Hold/sit in this invisible chair for as many seconds as you can (anywhere between 10 – 60 seconds depending on your leg endurance).