Over the years I’ve had a lot of hand and arm problems from using a keyboard too much. For the last couple of years, though, I’ve been pain-free and twitch-free. (There was an extended time when my little fingers and thumbs spasmed annoyingly day and night.)
There are lots of different kinds of keyboarding injuries, and lots of different solutions to them. I’ve changed my chair, my keyboard, my keyboard layout, my desk height, and so on. But one thing that’s made the most difference for me, and I suspect would help a lot of people, is strength training. The reason I believe it would be so helpful for a variety of different kinds of injuries is that low-force repetitive motions — i.e. wiggling your fingers lightly in an awkward position — is inherently weakening. That’s right, you use your fingers to type a lot, and you actually get really, really weak. Like, ridiculously weak.
I grew up on a farm, milking cows by hand. I had some kind of deeply held assumption that I’d developed an iron grip for life. When I started using a computer a lot, I never would have believed anyone who told me I’d become a weakling in the space of six months or a year, yet looking back on it, that’s about how long it took for the problems to start.
Almost universally, when someone complains about RSI, or when I see someone flexing their hand or massaging their forearm painfully, a quick look at the person’s forearms reveals that the muscles are horribly atrophied. Sometimes these programmers look like strange insects; their arms are just bones and skin.
“Grip trainers” — those little springloaded things you grab and squeeze — are not the solution in my opinion, and may lead to more injuries. I am not a doctor, so take this with a grain of salt. But I believe that the muscles and connective tissues of the entire arm complex need to be developed, not only for strength, but for stability, and this applies to the nerve systems as well. (A lot of strength is neural, not muscular.) Coordination, flexibility, stamina, speed, and precision also need to be developed.
Rather than getting tunnel vision and looking at the grip muscles — those muscles that curl your fingers toward your palm — I believe that a lot of other muscles need to be involved, too. One example: hold something heavy, palm-down, and then raise the knuckles in a reverse wrist curl. Those muscles are vital, and they get as weak as any others, but they’re hard to imagine training with a spring in your palm. That’s why “grip trainers” aren’t the whole solution.
I suggest wrapping your hands around something heavy, and doing hard things with it. Kettlebell training is an easy thing to recommend if you have proper coaching. Pullups, pushups, yoga, gymnastics, all kinds of weight training potentially including Olympic lifting, and jumping rope are all good workouts of various parts of the wrist/hand/arm complex. For a while now, I’ve carried a jump rope with me when I travel. Double-unders are a fantastic workout you can do anywhere, and they work pretty much your whole arm and everything attached (chest, back, shoulders, neck) as well as your legs, and if you haven’t done them, the cardio intensity is not to be underestimated.
In addition, there is a gadget that I love: the Powerball. This little gizmo generates force through precession, and your job is to work back against it, adding energy to the ball and making it spin faster. You can hold it in a variety of grips and move it in several different patterns, including holding it as still as possible. It will exert an amazing amount of force back against you, if you have the skill, speed, and coordination to work against it. You can spend a few minutes a day with this and not only make your hands/wrists/arms burn like hell, but develop and harden all of the tissues involved. It takes a little while to get the hang of it, but it’s probably the best overall prevention of RSI I’ve ever used, given its combination of weight/price/size/go-anywhere-ness.