Have you been checked out for lymphoedema? This could be a symptom. I'd suggest you ask your breast care nurse to take a look.
Any idea why my shoulder arm joint (the one with Breast cancer) would be feeling a bit dead? The circulation in thesame hand also a bit poor.
I did have scolosis (curvature of the spine) in my youth, aged 12 and ths side was affected, but no problems since then.