In a few previous questions, I mentioned that I sometimes daven in a nursing home minyan.
This past Shabbat, the gabbai asked someone who is confined to a wheelchair to daven Musaph. There were other non-disabled people in the shul. I assume that since this person was a guest, the gabbai wanted to give him the honor.
The prayer is called Amidah because one should stand for it, if he can. Is a shul allowed to use someone who can't stand for amidah as a shat"z if there are others who can stand?
The Jerusalem-based kollel Eretz Hemda has a responsa on this very topic (here). Their conclusion is that
If [a person is] permanently (or for a long time) in need of a wheelchair, people should get used to including them in all activities that make them feel included in a normal life, as their personalities demand and halacha allows. They should be allowed to be chazanim under these circumstances, certainly, as is almost always the case, when we are talking about one who is not a full-time chazan (or was previously appointed as chazan).
This appears particularly appropriate in a retirement house context where we know, from your other questions, that a number of patients have health issues. See the original for the full details and their tshuva in Hebrew in B'Mareh Habazak VII:3.
