Read the directions!
While I love these they may not be the best for my flat, no arch having feet-
I have switched back to regular shoes -but want to love these so much.
My arch hurts like hell so you are to gradually break these in rather then just wear everywhere all the time. I do believe these shoes allow you to work muscles in your feet you hardly use.
I normally have spasms in regular sneakers I don't seem to get them in these but again my arch or cent of my foot hurts after my walks of 4+ miles.

When I first started to wear them I had to put a gel cushion on my ankle because the shoe was cutting at that little bone and created discomfort and pain.
 So I am partial because I want to give these shoes a 5 but if you are not use to minimalist shoe please read the directions.
Everyone is different.