Humans walk heel to toe because of evolution, not shoe design.

“Scientists know from footprints found preserved in volcanic ash in Latoli, Tanzania, that ancient hominins practiced heel-to-toe walking as early as 3.6 million years ago.”

https://phys.org/news/2016-12-heels-toes.html

While JK Rowling may not have bothered to do a google search, neither did Katharine. The most accepted term for the indigenous peoples of the Americas is not Native American, it’s American Indian.