Aspercreme! I frequently have to use Aspercreme on my hands in order to get my fingers from getting stuck into painful hooks...LOL! Capsasin works for my lower back somewhat...at least I am able to keep my mind on the knitting a hand for a little while before I have to stop.
As far as the pain in the shoulders and the heaviness of the arms...what I do generally is go to bed and knit in a reclined position where I can use pillows to support my shoulders and arms. I can't knit sitting in a chair on on the couch for much more than 15-30 mins...so I had to learn to knit in bed. Some days I can't knit more than 10-30 mins at a time before having to re position myself with something or other.
I'm not complaining however because there was 10 years or more I couldn't even hold needles or hooks and make stitches consistently...so I'm happy just to be able to see and to be able to knit for now.