Definitely a myth! When cat nails express and then retract, the nail is not going up into the paw itself. When a cat relaxes and retracts the nails, this prevents the nails from touching the ground while the cat is walking. While wearing nail caps, the cat’s paws and nails are able to make all the same, natural movements as without. The nails comfortably extend and retract as long as the nail caps are applied properly – this includes being the right size for the cat’s nail, having the nail trimmed prior to application and with just enough glue to adhere.