They dont intend on starting the lift w/ a rounded back, but it eventually becomes physics. when what your holding weighs 2-3x more than you it becomes harder to hold a straight back. But when your getting to the 600 lb mark, trust me you didnt get there overnight. by the time your there your back is strong enough that it does not injure you, it becomes natural. And I'm sorry, but the vid didn't impress me a whole lot, half the guys were starting at their knees, and the one who actually managed to pull 600 weighed about 280-300 lbs. They'd feel pretty dumb if one of us walked up to the bar all calm and cool, and banged out 500/12. And we wouldn't need to scream and wear goofy looking shit either,hahahhaha.