This article is from the Ergonomics and Typing Injury FAQ, by Dan Wallach firstname.lastname@example.org with numerous contributions by others.
I don't know if WorkRite makes furniture or not. However they do make
another interesting item that many of us should have. In my experience,
most of the modular furniture makes no provision for having a mouse in
addition to the keyboard. WorkRite makes replacement keyboard trays that
are much wider than the usual 24 inches or so, allowing the mouse to sit
on the same tray as the keyboard. Novel idea! ;-)