Comment by trailbits

I did experiment with using a trackball taped to the floor. It's hard to get precise positioning moving your foot. I think using the tongue along the roof of your mouth would be more precise and less fatiguing. What was more useful was a set of 9 foot switches that could be programmed to send arbitrary keystrokes. I could off load from my hands the most common keypresses I do all day, for example: pageup, pagedown, tab, enter, backspace, mouse click, passwords... along with speech recognition software you can get at least non-coding tasks done without using your hands too much.