In my experience, form follows function. Often deviations of running form are from habit or training, accommodation to body style and finally function. As we see on the treadmills in our offices, when the person is locked up, their pelvis does not move properly, thereby making it impossible to stride properly. This results in pain, overuse type injuries and other problems in the body. Check this article out. Let me know what you think?
I came across this article on running form in runners world. Apparently, someone watched the form of a marathoner to see at 300 frames per second how their running form affects their run and their speed. Read this article at http://www.runnersworld.com/article/0,7120,s6-238-267-268-13951-0,00.html?cm_mmc=Twitter-_-RunnersWorld-_-Content-Training-_-DoesFormMatterMayIssue.