Originally Posted by KingJulien
I have to question this advice for anyone who isn't a powerlifter. The purpose of having a huge back arch is purely to put up higher numbers by shortening the ROM of the lift so that you don't have to bring the bar down as low, right? So if you're not just trying to put up numbers and just want to get stronger, you'll want the larger range of motion, I'd think.
My post was in response to jabster who is a competing powerlifter.
There no need to have a huge arch for anyone who is not a powerlifter.
A small arch will however put pressure on the traps/rear deltoid area so they are kept in place during the movement. No matter what your goal is, you want to have a stable phase to press from (unless the lift is some form of variation of the bench press that includes instability).