My friend and I were doing squats and I saw a female trainer looking at us. I immediately knew she was going to come over and talk to us about our form. We were going a2g with toes pointed slightly out...same form as the video Ceaze posted with the Olympic training coach. She asked, "Why do you go so low?" I wasn't trying to be rude, but looking back on it, my reply of, "Because that's proper form" wasn't the nicest way to say it. She said, "Well if you're doing powerlifting, then yes, but otherwise it's better for your knees to stop at 90 degrees or even somewhere before that." Granted, I'm not the best at the logistics behind going deep, but I tried to explain it as much as possible. I told her how there is more strain on the joint when you stop at 90 degrees and how you recruit more muscles with the greater range of motion. All she replied with is, "That may be true, but I'll feel bad if you come to me and say, 'I blew out my knee'." I made an analogy to bringing the bar all the way down to your chest when you bench press vs. stopping when your elbows are at 90. I got essentially the same response, "Yes, but there's a better chance of blowing out a shoulder going that low." I wanted to just say, "Well there's a better chance of injuring yourself if you move, so you should just stay stationary all day long." Then she proceeded to ask why I squat with my toes pointing outwards instead of straight forward. I told her I naturally have open hips, plus I can go deeper with my toes slightly outward. Next time, I'm going to pretend like I don't speak english.