IMO, discussion of :Buddhist vs. Taoist" philosophical, ideological, political and/or religious aspects or meanings of "internal" and "external" takes us away from the bottom-line issue that the OP seemed to be asking, which is, what are the physical qualities of "internal" and "external" body methods that distinguish them from each other.
Well. . . IMO, no. It doesn't, and I was the OP.
Cady, I suggest that you re-read my initial post with a more open mind.
This is a complicated topic, and I would really appreciate if everyone took the additional time and effort to lay out their positions brick by brick. There is a strong tendency to offer conclusions as explanations and analysis. This does a disservice to us all.
I was aware of the probable origins of these terms long before I started this thread. Dismissing the fact that the terms were meant to describe geopolitical and religious-philosophical differences and not the quality of movement of these arts is precisely the type of carelessness that I am alluding to.