I've had some low back issues in the past, but this exercise takes that out of the equation via the chest support pad. It's a safer way to work through the entire range of motion.
Adding bands provides continuous tension which increases the intensity in the contracted position. Give it a shot!
Prior to the early 90's, hardly anyone used scientific references to support their notions – not in real life and certainly not in the magazines. You just said what you believed and most of the time no one questioned you.