Okay, I need some help with doing lunges... It seems that whenever I attempt to do them I feel really off balance and like I'm gonna fall to one side... I have real thin knees naturally so maybe that contributes, I don't know... I'm tired of doing leg extensions and I want to substitute them for lunges, but alas, I can't keep my balance... Any tips you guys may have? How far apart to place feet, where to look, etc would be great!