I am a vocalist and a guitarist, but I suffer from wrist problems, so if I want to ever heal from them, I have got to play music for a while without using my hands too much (as long as there is no hand strength or strong grip required, it's fine). Examples I've found for instruments which follow the criteria are: Harmonica, recorder, slide-whistle, kazoo and theremin. I am unsure if an electronic unweighted keyboard would also match the criteria.
So my question is: Which instruments could I play that would match the previously said criteria?