It's awful isn't it. Mine is all due to arimidex. I was becoming more rigid every morning and when I finally got to sit down at night very stiff and uncomfortable to then stand and move again.
I started seeing a great physio who has given me stretching exercises to do twice a day for 10 minutes. After 3 days things had dramatically improved. I've been lazy over Xmas and I'm back to square one! But today I started again. It's been my answer.
He explained that the sheaths around the tendons had become ridged causing inflammation and this upsets the nerves. ( think I got that right), also my archilles was very inflamed. He did some pretty mean massage, used special tape for a few days and with the stretches almost normal. hope this helps. Oh and if you hate exercise like me.... These stretches are mainly done lying down :)
Janine xo