Don't forget about your ankles, they need to be engaged as well as your knees.
I find peeling my shoulders back helps, if your shoulders are slouched forward your back will follow. Same thing with your arms, if your reaching for the ground to protect against a fall then your back is going to follow your arms and hunch yourself over. Its easy to practice the proper position at home, just squat in front of mirror and make sure your not hunching over.
Last edited by brucew.; 03-12-2013 at 02:25 PM.