Birkenstock Arizona have been my favorite sandals for over 15 years.  I didn't wear sandals for years after I started using orthotics in my shoes, the orthotics cured recurring knee and hip pain, so I wouldn't chance wearing sandals without support.  I read about the great support provided by the Birkenstock sandals (this was during the Teva rage, I looked at those first).  I bought a pair of the Birkenstocks and have never regretted it after 7 or 8 pairs.  I did deviate to a pair of Clark's waterproof sandals, but they are worn out now and Clark's no longer makes the model.  So, back to the Birkenstocks, never any joint pain with these.