This is what the bottom of the squat should look like: knees way out, back arched, chest up. Push the knees out hard all the way down and all the way up. Drive the shoulders straight up toward the ceiling like you are trying to throw the bar off your back. This posture will allow you to fit your belly and those hip bones in between your legs, and utilize your strong glutes and hamstrings. You should feel your ass working! With your legs abducted (taken away from the midline of the body) your adductors are able to contract properly from the bottom of the squat and help drive you up by opening the hip. This correct posture takes undue pressure off the knees and balances the forces acting on them.