I too have pain in my upper back area. I do notice that when I'm knitting that I catch myself with just my head bent forward. So that's why I'm so sore up there, but the other place I really hurt is my left finger/knuckles. The ones at the top of my hand. They just scream at me whenever I pick up my needles!!
I try to hold it a different way, but I can't seem to do that. Plus I don't notice myself gripping the needles hard at all??? So I'm not sure what that's all about.
But I just plow through the pain!!
On a side note, I just finished my first dog sweater - kind of - I have to sew the top part and I don't get how to do it???!!!! I'm trying to read it out of SnB, and I watched Amy's video, but I'm still struggling.