It used to pull me forward even with clean grip (never used cross) because I was not very mobile.
I rarely stretched when I was bb'ing. It's taken about a year of constant mobility work :/
I couldn't even overhead squat a pvc a year ago haha
I'm not a proponent in crossing the arms, it causes many issues overall....different topic/thread.
I can't use an oly grip, so I use straps, wrap them around the bar and pull your elbows up....wedge that bar within that pocket just below your adam's apple/collar bone area and keep the elbows up almost to the point of pulling them, this should alleviate the strain a bit.
However BI's wife is 195lbs, pulls 5 plates, has 18 inch arms and will kick the shit out of all of us at once.....so him using her as a reference is utter bullshit! hahaha
Edit: I see Schultz and BI already mentioned the straps.
It could be mobility issues when you lower yourself which would make it difficult to keep/hold an arch. It could also mean you need to work your upper back more to have the strength to hold the arch and not begin to come forward.
Yeah upper back is pretty damn strong. Mostly a hip mobility thing for me. I think the thoracic flexion was a side effect of over compensating for lack of hip mobility.