I've got a question, whos saying these people are disabled???
If they have a "Doctors note" that says they have a problem, then we have to be careful not to descriminate against any disability. So if you come to a shoot and have a note saying that you can't stand or kneel we have to support their needs, but I agree there should be no advantage gained. So bring on the doctors note stating you can't stand or kneel or just get on with it.
Coz in all the years i've been shooting i've only seen 2 doctors notes, the rest have all been word of mouth.