Moving from "Proper" and "Right" to Understanding How the System Works

So I was on the Runners World forums the other day and I posed a question just to see how it would go over. The question was essentially designed to see if anyone understood the principles of running movements. I don't want to post the whole question here, but I'll give three different questions that kind of summarize what I was trying to get across. Basically, "what does the leg NOT on the ground offer to the one that IS on the ground?" Or "How do they relate to one another?" Or "What goal is the leg touching the ground supposed to be achieving and how does the other leg (and the rest of the body) assist that purpose? No one who responded to my inquiry knew or had any idea.

The most common response I got was "You're overthinking it." But no one could actually answer the question with any understanding. One response included this: "Try to be efficient with your form and things should work themselves out."

I know there is credence to the idea that our bodies will become more efficient on their own, but really?

There seems to be a lack of foundation in the running community. Ask anyone about running form and they will tell you what you "should" do or what is "proper from." But ask them why it is proper and no one seems to know. If they did know, they would proceed to tell you the purpose of that movement, which is exactly what I'm trying to figure out.

In the next post I'll answer my own question. Stay tuned.