I'm sharing this with everyone because my response was "WHY DOESN'T EVERYONE KNOW ABOUT THIS?!?!?!" which strikes me as a good reason. It's ridiculous that you've gotta bust yourself up and do hard time in a chronic pain clinic to learn some things. May it help all of you.
Disclaimer, I am not a physical therapist, let alone a neuroscientist. So I'm sure I don't understand 100% exactly how this works. But I do think I got the gist of it, and it's one of those lovely things that is completely safe unless you've got a compound fracture or other massive traumatic tissue damage, in which case, you will know it. It is definitely within the 'can't hurt, might help' category.
As I'm sure we all know, the brain gets massive amounts of information from our nervous systems, and has a protocol for what it ignores. Think about it; you can't pay attention to every signal coming in all the time. You just don't have the attention span for it. And you sure as hell don't need to be aware of EVERYTHING. Right now I bet you're not noticing the feel of your clothes pushing on your body, at least not until you think about it. Once you think about it, oh yeah, it's right there. Then you pay attention to something else, and it fades into the background again. That's the basis for this painkilling technique; distract the brain and give it something to pay attention to.
In the overall big picture, the brain pays attention to movement signals before it pays attention to sensory input (including pain), because it's REALLY important that we know where our arms and legs are and what they're doing. So there you go. Getting a pain signal from your hand? Wiggle it around a little. Your brain goes "ooh! movement!" and tracks on that rather than focusing on the pain. The pain is still there if you think about it, so don't. But this is a fantastic, almost instantaneous way to get dull aches and pains to shut the hell up for a while.
When being taught this, I remarked that it sounds like when you bump into something and then rub the ouch to make it go away. In terms of the brain it's not EXACTLY the same thing, but it's very similar.
The movement doesn't have to be large; it can be a small 1/4 inch or 1/2 cm wiggle. Just enough to get your brain's attention. Don't do it for more than thirty seconds. If it's going to work, it'll work in that first half minute. THIS DOES NOT FIX INJURY, including repetitive stress injuries, so don't knit for six hours straight, wiggle your fingers, and go back to it. But for shaking off the stupid aches and pains we all get in winter, it seems to work.
I've been fooling with this technique since Monday and I'm quite boggled at how well it works, and not just on my stupid hand. With luck it'll work as well for everyone else. And even if it doesn't, hey, no cost, no risk, no allergies, woohoo!