But one's thumb doesn't rotate like that. If one needs to make one's thumb rotate to use a trackpad with a thumb and another finger, that trackpad must be the s

But one's thumb doesn't rotate like that. If one needs to make one's thumb rotate to use a trackpad with a thumb and another finger, that trackpad must be the size of a sheet of paper. I'm probably misunderstanding. I think I'd need a video to understand what you mean.