Not that it matters, but I don't think his lower back is rounded at all. His upper back is rounded to all hell, but the lower back is neutral or slightly arched still. The upper back rounding reduces the bar's path I s'pose?
yeah, KK has that technique. If you watch some of his vids, he kinda sits there and stares at the bar. I think he is slowly rounding his upper back while maintaining a lower back arch.
I wonder if that unique technique is why he wears his lifting belt under his hooters.