Change your diet to decrease the amount of uric acid your body must eliminate, i.e. eat less meat. Uric acid builds in the joints and causes stiffness and pain; this is one reason most yoga people are vegetarian (not that I am, just passing along the "good" news). Hope this helps.
Oh!!!! So that's it! I've been striving to discover the reason that I have been dubbed "the freak that can't be pinned."
I've been a vegetarian for about eight years now . . . maybe nine. Now I can claim that the fact that nikkyo doesn't hurt is more than simply the result of a freakish deformity!