It would feel different, the array of musculature that's used is generally different, and it's employed in different ways (along with some additional activators and controls) - but nobody who's really studying IP has claimed that no muscles are used at all.
Still, the difference is big enough that it has confused physical therapists who were expecting something else to happen - and that's partly the point, that confusion is itself a big advantage.
The scientific stuff is interesting - to a point, but too much of it doesn't really seem to help in actually doing this stuff. The old standbys of visualization and imagery that have been used for thousands of years are usually the most effective in that regard. Phil Jackson and the Eastern European Olympic coachs seem to have reached similar conclusions, in many ways (in terms of the value of visualization, not as related to IP).
Thank you for that Chris
Just to clarify, as I pointed out to Janet, I referred to not using "conventional muscles". I did not say moving using no muscles at all.