Did these flat backed for a bit more Hamstring work. Much like the Piper Squat works my Vastus Medalis like nothing else, these Underhand Deadlifts hit my upper back like nothing else. I've been training 35 years, competed in Strongman, Powerlifting, Weightlifting, Olde Time Strongman and Gripsport when something hits unlike anything else you've done....YOU PAY ATTENTION!! This is partly why I'm all about trying new variations of lifts. I think you could possibly be ONE VARIATION away from solving a weakness issue. You'll never know if you never try right?? Good Luck & God Bless!!