why all the comparing dumbell to barbell rows? they're not the same as the hand is in neutral position with dumbells. YOu can't pronate or supinate heavy weights with dumbells, so the barbell is needed for different hand postitions. As far as how much do you bend? There is no one size fits all here, there never is, so vids like that, bofff, useless unless totally clueless.
Lot's of guys with huge ass backs doing it "wrong" according to that fuckhead Piana who made the video, can't stand how he talks, sounds super condescending, he can eat shit, as usual.