Only after reading Born to Run by Christopher McDougall did I first hear about this. I always thought that our feet needed heel support, ample cushion, arch support, etc. But after further research and trying it myself with a proper transition, I find it extremely hard to believe how long it took me to realize this. Our feet were already made for running, and running shoes have made our feet weak by attempting to do the work for our feet. Heel-striking is a result of a large heel-toe offset, and it shortens and weakens our Achilles and calves. This was the main cause of ongoing knee problems that I had, which have been completely resolved by my transitioning to zero-drop shoes. It is the best thing that has ever happened to me as a runner. Now, I ask, why is this so hidden from us, and why can't we all come to realize that we were born to run without supportive footwear?