I don't think actually compelling is always necessary. Certain aspects demand certain types of actions, even without a compel. If you are "on fire", you are burning, your immediate reaction should be to do something about it. If you are on the floor, you need to get up before you can do any running around.
That's not the same as being compelled to do something. It's just a logical conclusion of the story. You just can't do everything from any position you are in.
However, if that maneuver forces you down a specific way, and that's to your detriment, that's a compel. But I wouldn't count "prone" as an aspect that's going into that direction. Compelling "prone" in a conflict would, to me, mean you can no longer try to stand up. But why would "prone" make you do that? Now a "busted knee" could work for that. As an aspect, it just means you knee hurts like hell and your opponent can tag it to say he can use that to his advantage, because you are reacting slower or because you are favoring the leg. If you compel it, you can't use your leg at all. The other guy runs away? You can try and crawl after him, but you're not getting far.
As for the actions: creating a an aspect with a maneuver is an action, removing it should be, too. Unless you have a stunt or power to allow you otherwise.