what would you choose for that purpose: a trackball or vertical mouse?
It really depends so much on your particular wrist. To be honest, what I would do is buy both and try both and keep the one you like and re-sell the one you dont like (resell on ebay/craigslist/amazon or elsewhere). I'm a big believer in trying out hardware in person like that, you can really re-sell almost anything and usually get almost all your money back.
(and as a bonus, so long as you have both, write a review of them for geekhack
)
To give you an example, I had RSI once (I had to wear my wrist in a cast for a while!), and began a search for a more ergonomic mouse. For me, one mouse didnt solve my problems, but a combination of mice did. I wound up buying a trackball (and even with trackballs, only one particular model and brand wound up working for me, the other brands did not), and used it in combination with a usb trackpad I found on amazon (which I placed underneath the spacebar of my keyboard). Using both together solved the RSI issue. (And once it went away, by the way, I no longer have either of those, I went back to a regular mouse and have not had problems since - so go figure). But in both those cases, I used the trackball and trackpad for about one year, and then resold both for about the same price that I had bought them for.
The wowpen may not have a big resale value if its not that well known but on the other hand I find that ergonomic devices keep their resale value very well and are always in demand by RSI sufferers.
Anyway that would be my advice, get both, use both, resell the ones you dont need. Your wrist will thank you
It doesnt make sense to skimp
too much on hardware that you use every single day all day.
(That said, if you absolutely have to choose between them, I think both will be ergonomic, but the vertical mouse will have a slightly higher adjustment period. I used a vertical mouse once (our secretary at work has one, whenever I fix her computer I use it) and when you're new to it, I found it to be really *wacky* to use, I would need to use it for about 5 days before I felt comfortable with it. That said, I could see how it would keep your wrist totally vertical and straight). But the trackball also keeps your wrist at a more natural angle and is much easier to adjust to). The trick with RSI (my doctor told me) is that the wrist needs to be as straight as possible, all the time).
