If you think about it, this approach can only work for stopping actions in a way your body is capable of stopping. If I begin throwing a punch and reach a point where I cannot use my muscles to stop the punch before it hits your face, you're going to get hit. If you accelerate a fist for 300ms, and then try to stop it in the last 10ms, as though you hit a wall, you'll find you're just not strong enough.
It turns out that for much of what we do, it is actually possible to stop motion in exactly the way you describe. We generally try to operate in that portion of our capacity because it's safer -- we can undo mistakes. Many martial arts train this skill, and one reason they do so is because it's an excellent way to learn what actions you can do without committing to them, and what actions are committing you to a course of action you cannot stop. It's also quite clear that mimes engage in this sort of action. Their ability to create virtual walls is literally legendary, and a perfect example of the kind of control you are talking about. The existence of mimes shows that it is possible for muscles to be controlled in this way.
The result would be that you could use electrical nerve inhibition to stop your fingers as they touch a virtual wall. At that point, your muscles are simply commanded to "station keep" as though they were resting against a surface while you override the sensory nerves to give you the illusion of touching a wall. However, if you punched at the virtual wall hard enough, you may be able to punch through it because you got too much momentum going before the augmented-reality circuits realized that they needed to stop you.
Alternatively, they could inhibit your motion before you get to the wall. If your punch "goes soft" right after you begin to accelerate your fist, the augmented reality engine could keep your hand moving within the speeds and angles where it can stop it when it reaches the wall. The result, however, would feel very awkward. You would always feel like there's something trying to hold you back. Likewise, if someone starts virtually punching towards you, your arugmented reality engine might manipulate you into a position where, upon "contact," your neck, core, and leg muscles are in the position to emulate the effect of being struck.
The interesting question happens when you move into the world of your own internal desires. What if the augmented reality engine could convince you that you don't want to punch the wall, because it knows that your muscles aren't in the right position to let it inhibit your motion. If it could do that, you wouldn't feel like you're being held back at all, because it wouldn't be stopping anything you want to do.
Science fiction rather than hard science? Perhaps. However, there are real-life examples. Personally, I practice a martial art which uses these exact principles to send someone flying backwards without applying but the tiniest of forces. How it is done is all body positioning and mental preparation and all those things, but in the end the physical backwards movement is typically caused by the victim trying to regain balance and shooting themselves backwards with their own legs. So not only is this sort of thing possible, it's actually done in real life. I can do it.
Of course, we do this as a drill, in a school setting. It's a tool to fine tune the skills you would want in a fight. It's not assumed that we will be able to always bowl over every opponent without. The ability to defeat any opponent without force is the ideal goal, not the reality. When you think you can do it in real life, that's called huberis and ego. For an example of what happens when you cross that line, consider this video. A Kiai master had refined his art sufficiently that he believed he could stop anyone with his "empty force," using effects which are remarkably similar to what you want your augmented reality system to accomplish. He could demonstrate this on his students, of course. He put up a few thousand dollars to anyone who thought they could best him. A MMA fighter took him up on the bet. I'll let you watch the video to find out what happens.
I will say that it's remarkably hard to prove that this sort of chi magic is impossible in general, but it is very easy to demonstrate one person's failure by punching them in the face repeatedly.