Thanks guys. I thought myself that it was just muscling but then second guessed myself. Sometimes it's hard to take a step back and look at your own horse to try to decide if you need to up the groceries or just continue to slowly bring up the correct work.
It is a weird angle. His back feed are going through corrective trimming and we are only half way through the process, so yes they look a little odd. He has also recently learned how to use his shoulders and back so now he does tend to ignore his "back motor." A year ago he was all Butt and upside down neck.
I agree with Yogiwick too. It's hard to remember to not be stuck on the typical "Paint." His breeding is only 1/4 paint, he just has APHA papers. He is more TB than anything else.