On ergonomics

I noticed yesterday and this morning, seemingly for the first time, that I tend to hunch my shoulders when I type. I'm sure this has something to do with ergonomics, but I'm not smart enough to figure out what, precisely, to do about it. The way I type (70 wpm hunt-and-peck) doesn't always lend itself to resting my elbows on the armrests of my chair, either at work or at home. I have an under-desk keyboard tray at work, and had one at home before we moved to E3HQ, but for right now, my keyboard is on top of the desk there. Both are tilted toward me, which I understand is ergonomically poor, but I haven't trained myself to type on a downward slope yet.

I'm sure this has something to do with the fuckery going on in my shoulders, and possibly in my wrists, although the typing-for-15-hours-a-day isn't helping either. Damn you, wiki software (and job, incidentally)!