Do not waste your money.  I am a critical care nurse that is on my feet 13 hours a day.  I suffer from occassional sciatic pain in my lower back/leg.  This shoe does nothing to relieve that pain.  The concept and design of the shoe sounds like it would help.  But for some odd reason my left shoe feels as if it is missing some internal cushioning within the sole, as it feel "flat" when I walk in comparison to the right shoe.  They do visibly look identical, and I cannot see any differences.  I stuck with them for a whole month to see if it just needed some getting used to...on top of the fact that I had just spent over a $100 for them.  After the 30 days it is without a doubt one of the worst shoes I have ever worn.  HIGHLY DO NOT RECOMMEND!  do not waste your money.