Are your feet plantigrade, digitigrade or unguligrade?

This thing about landing on the front of the foot - it is not immediately obvious why running barefoot should encourage this until your heel lands on a stone. Ouch! Somehow the ball and toes ameliorates the landing. BTW, for those interested check out this link which is an excellent treatise on barefoot running. (If you are not interested why are you reading this?)

The primary reason is that the ankle joint, the length of the foot and the calf muscle provides a suspension system - a springiness or cushioning. When running on difficult surfaces I consciously raise my ankles to increase this effect.  If I land on the heel there is very little cushioning (hence cushioned running shoes encourage landing on the heel).

The sole of the foot and the toes have an abundance of nerve endings so that I find my feet are almost caressing the ground, but more important is pain. The above suspension system spreads the impact over a fraction of a second of time, long enough to react to pain and adjust one's landing (hopefully) and thus avoid injury. At the same time my eyes are picking the best route through a difficult terrain, Mowgli-style. Which the shod human is largely agnostic to.

plantigrade, digitigrade and unguligrade feet

Few mammals have a heel in quite the same sense as shod humans do. A dog's paw is divided into pads which answer, I suppose, to toes and the 'ankle' joint is somewhere way up the leg. Our dog can happily run full pelt on our gravel drive. I suppose the stones find their way into the gaps between the pads (or toes for humans). 

However it works, it works.  And it explains why we have toes.