For narrow foot, DANGEROUS! Sandals won't stay in place! While walking, shoe can (1) twist almost 45 degrees so that your heel comes down on  edge of the shoe and you stumble or fall or (2) slide forward so that your heel has an extra inch to go to the ground (same as stepping into a hole). On steps or stairs, (3) they can slide forward (toward toes) making your foot  1-2" longer and catch an edge of next step and throw you. They can even (4) slide off  your foot when you slide back from a table or desk. Hope you enjoy crawling under stuff! And this is after wearing them only 3 weeks!!! Problem is material; imagine cutting elastic band off shorts, replacing it with belt loops that act like shower curtain hooks.and expecting a smooth plastic belt to hold them up. Expected better from Adidas.