I'm not sure what it is girl, but I tell you, my knees hurt me soooo bad if I am on my feet too long. And I mean they hurt BAD. The ONLY thing that helps me is to take THREE Advil and rub my knees with Aspercreme (the one with NO scent, lol) - and sometimes soaking in a hot bath will work too, or a heating bad. My knees are just terrible and so are my legs...they are always hurting me, so I feel your pain, LITERALLY
