Since the first time I tried typing, as a kid, I have always had this problem. If it's just to type a few words, or a 200 word paragraph every few hours, then my typing speed is usually 60wpm. But see, if I was to start typing, and continue for a while, my hands quickly get tired. The first 5 minutes, I'd be typing at 60wpm, then my muscles would start to pain, and then I'd slow down to 50wpm. After 10 minutes, I can't move my fingers. I'd have to rest my hands for 30 minutes before starting up again. I've watched other people, and they don't have this problem. they can type at their 80 to 100wpm for HOURS AND HOURS with no breaks. I don't understand. I sit upright, back straight, arm's length away from keyboard, palms never touching the surface.