Originally Posted by
Mia Inman
Re your grip issue. Your wrists are a little bit flexed, and that can cause issues with elbow/upper arm pain. Straightening them out might help, but that may be difficult given your shoulder mobility. Keep working on that low-bar stretch. Over time, crank the elbows down a bit too, if you can. That will help with Jeff's observation about keeping the chest up a bit and the back in extension.
Question, is the bar just below the spine of the scapula or do you have it set lower than that. If it's too low, you could be trying to pull the bar up with your hands to keep it in place and that can cause some pain. Just something to check, I'm struggling to tell bar location from the angle in the video.