If this was an episode of MythBusters, I would say CONFIRMED.
Yes, it is possible to do all sorts of standing arm, shoulder, and wrist locks that can be finished without hitting the mats.
You will be surprised how simple they are, and how quickly you can get people to tap in a panic!
However, you will find that it is difficult to perform some of these submissions in a controlled manner – as they require explosive power to finish. So I wouldn’t advise going balls out in the gym, unless you want to be public enemy number one. 🙂
Still, they are very useful and I have a little series that I have made that connects 4 techniques together in sequence. The first technique is the Standing Arm Lock. It is very simple to setup, and can be done at least once in any match with no problem. Check it out