no I do the same. I developed this habit because I was a swimmer. I use to walk around cold wet floors all day so I got this habbit from a friend who would walk on her tip toes when the floor was cold. it was her reaction. the souls of our feet are so hypersensitive because of all the nerves so I'm guessing you do it to protectcyour feet from the temperature. it could also mean your traumatized because you most likely stepped on something that was on the floor that hurt like h3ll. that's why I do it now.
Could have to do to with the muscles in your foot, near your heel. They might not be fully developed and cant be stretched normally. its somewhat common I think, usually u notice when youre in your younger years. Its also a sign of autism
It is a tightening of your muscles, if it is bad enough it may require surgery. My cute little neighbor girl,just had it done and now she walks normally. Don't let it continue because it can cause hip, foot, ankle, and knee problems at a young age. It is a serious issue that Gould addressed, it could affect your future health.