I broke my back two years ago and have had persistent low back pain ever since.  Clarks Unstructured line of shoes are the only non-sneaker shoes I can wear for a full day of work.  The rubber soles and supportive insoles relieve my back pain and are comfy on my feet as well. I own several different versions, but I particularly like this one.  I have them in olive and am getting the maroon too.  Of the fully closed Unstructured shoes, I think they're the cutest, although they do look a little "elfy" and fare much better with pants than skirts.

Update:  While I still love these shoes, there is one serious flaw to the entire line of Clarks Unstructured shoes--they wear out and look old fast. The color fades very quickly on the toes, leaving really noticeable lighter spots, and the insole wears out quickly, losing a lot of the spring that makes these shoes so comfortable.  Clarks does not sell replacement insoles.  Why would they, when they can force you to buy a whole new shoe?