Mr. B&A, you're a man of strong convictions, and I admire that, especially in this day and age of cynicism and societal ennui, but I think you can understand my position as a recreational runner who is looking to think about more and perhaps even willing to work on better form and a more systematic training regimen, for the first time, really; namely, that I should first try to understand the mainstream, elite theory and practice of all things running, and then perhaps look into more novel or cutting-edge models. But I can tell you right now that the idea of using gravity, a vertical force, to propel one forward, which involves a horizontal force, sounds pretty suspect just on pure physical/logical grounds, and therefore it's difficult to see how leaning would be of any biomechanical advantage, and indeed, one would think it must create inefficiencies in smooth delivery of power and extension through the piston that is the upper thigh and hip/butt complex, as 'core' muscles are given a greater functional load away from supporting this action and towards maintaining stability and balance.
