Been wearing barefoot shoes over a decade. Only so much defense you can build up against kicking a boulder.
Discussion
Sounds like you haven't been training your feet to the max, for instance, you could be INTENTIONALLY kicking boulders
Not the first time I've been told to go kick rocks and it won't be the last either I'm sure.
I was going to ask if you were dragging your toes on the concrete again? XD