Just to be clear, since some old articles of mine from the early 90's are being used, part of the question was and is how to say something so that people can understand the concept in order to get their foot in the door. The problem with "shear" forces (they're referred to as "contradiction forces" or "antagonisitc forces" in the old literature) is that the way Erick presents it conflates the meaning with simple muscular tension. There's more to it than that; how you train for "contradiction", etc., has a lot to do with breathing techniques and "jin" forces and conditioning the body. If it was simple, everyone would be doing it. "Shear forces" is enough misleading that I would personally discard it.
FWIW
Mike Sigman