When you first put these on and stand up, they are so springy that it takes a wee bit to adjust.  My knees say, this is the best.  As a Floridian, I wear sandals the majority of the year and these have been worn every day. I have slightly wide feet and these are a bit loose, but not enough to cause a problem.  So if you are one of those people with slender feet, better look into a different style.  I plan to get the Croc style sneakers for those times that require covered toes.