The Bat-Keyboard was a non-Qwerty chorded keyboard that aimed to make it easier and faster to type.
Possibly beneficial for certain types of muscular or tendinous ailments? I don't know.
Chorded keyboards and keysets have been around since the 1830s on the telegraph, and they have been tested many times in computing. Notably by Engelbart on the NLS and later on the Xerox Alto and others, but they have never seen popular adoption.