How much pain from Arimidex???

[PinkGirl]

Up until a few days ago, the pain from Arimidex was only in my feet and also a very, very, stiff feeling every time I got up from a chair or from bed.
The last few days I have had severe pain in my ankle and one of my knees. It feels like I sprained something, but I know I didn't. Can Arimidex cause real bad pain, and does the pain usually start out mild and then get worse???