They are not “fixed” and will slide toward the back, which loosens around the heel/ ankle area. Crocodile is getting hungrier and thinner, and Chicken is getting fatter. I find these are the most comfortable indoor outdoor slipper, I have neuropathy in feet from treatment, and these help cushion the feet as well as keeping warm in colder times You put your foot through the ankle loop and slide in. I dont accidentally click on them like other ones Ive had. not even a month ago . When I did they were concerned about the stripe I had across my foot. I use it with our Titan Fitness 2" Olympic Plates Bar. Ive worn them around to run errands or on short walks, also, and theyre very comfortable. I used Command strips, and so far so good.