Hi I've noticed the great influx of press to handstand questions and I have one that is a little specific. When I attempt a straddle press to handstand from a seated straddle, I have trouble. I round my upper back and it looks like I am trying to press up vertebrae by vertebrae. When I watch other girls do it, they keep their back moderately flat and press mostly through their shoulders rather than round their back. Any ideas why this is happening? I suspect that I have a weakness in a particular muscle group but I'm not sure which one.