-The primary design principles of the body are safety and efficiency, in that order.
-Muscle movements can be divided at a high level by purpose: balance vs. manipulation.
-The guidance system behind a set of movements can be said to be operating in "feedback" or "feed-forward" mode.
That last was the most interesting to me. It's illustrated well by occasions where you mis-judge the number of steps going down stairs -- the jar when you discover the mistake is evidence that you were in a "feed-forward" state, in which a large chunk of muscle movements are planned ahead based on routine and familiarity with the environment. I think also of how horses can't see their feet while they're in motion -- they're continuously mapping the ground ahead for where their feet will land. Most familiar motions are executed in feed-forward mode.
A great contrast from my own experience is the Tia Chi walking I do at Twilight Covening when the ritual involves blindfold walking through the woods. Feedback walking is all about feeling the ground with your foot before you shift weight onto it, as opposed to finding out what's there when you land on it.
This has huge relevance for any kind of touch therapy. If you're touching someone in feed-forward mode any sensations you're receiving through your hands are coming too late to make a difference in your contact. If you're touching someone in feedback mode your contact is fully informed by changes as they occur. It has to be slower, never committed to full follow-through of a given motion because you may get information part-way along that says you should stop the motion sooner than you thought. (Or equally, continue further than you though -- you're always finding out as you go along.)