Just reading a book on running technique, “ChiRunning”:

“… the ChiRunning technique is backed by the laws of physics.  One scientist even told me, ‘I wouldn’t do this if it didn’t work in terms of physics.  It makes perfect sense to me, as a scientist.’  When your body is out of sync with these laws, it becomes less efficient, requires more fuel, experiences greater fatigue, and is more susceptible to injury.”

Sad but true.  Breaking the laws of physics is a risky business.