Interesting article but that article says that heel striking may be better for speed...wha huh? If you sprint 100m, do you heel strike...ummm, no. When you run a 400, do you heel strike...umm, no. So you don't run faster with a heel strike, because if you did you would sprint that way. Also, while the calcaneus may be a less fragile structure than the forefoot, it has to be because when you land on it the impact forces are greater. Lets all pay attention to the 5k and 10k at the olympic trials and see how many of these guys heel strike. I am going to bet none. While you may see some doing it at the end of a marathon due to fatigue, it will not be their preferred way to run. Someone said the best way to run is the natural way for you. Well, take the blasted shoes off and run on grass. If you heel strike after 3 minutes, maybe you should heel strike, but I don't think many at all, if any, will. Now the shoes we wear should only serve to protect the bottom of our feet from things underneath. Why the hell are people wearing shoes that change how they run compared to when they don't wear shoes. That's the whole point.