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Title: Do not buy thumb trackballs if you want to avoid rmd!
Review: If the reason you buy a trackball is for ergonomic reasons (you have sore wrists, repetitive motion disorder, or whatever) DO NOT buy a trackball that is driven by your thumb. BAD IDEA! I did and my thumb started getting sore after about three months of using it. Get the trackball that is driven by your fingers, so you don't have to move your fingers at all.
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