HBP/PE8

So my question is two parts. When i'm doing my reps are my shoulders supposed to be back and locked or is it ok for them to round forward in the bottom position. And secondly at the bottom postiion, my torso stays upright but i can't keep my legs underneath of me, the come forward almost coming into an L hold postion. Is this ok, and if not how/what can I do to correct this? Thanks in advance. -Matt

can you post a video?

My shoulders round quite a bit forward and I'm also not sure if that's ok. In the video it's hard to tell because it's from the front but I believe his shoulders come forward as well. If you don't post a video I can post one.