Re: Teaching injured or elderly students? Is Aikido for everyone?
Assuming that the students in question came to you voluntarily, just simply ask them. Our student application asks EVERYONE signing up if they have any medical conditions that we should be aware of for their safety. We explain that we don't care about their medical history and aren't prying, but want to be able to respond to any emergency in an appropriate way. I haven't seen anyone get offended or balk at all - someone will today of course. We make it clear that we are just trying to protect them from unnecessary harm.
Secondly, we expect every student to participate to his own level. If you have to sit out for a few minutes to rest, fine. If you have something limiting you from doing a particular thing such as shikko, fine, just do something related that you are capable of. Do the most you can without causing harm to yourself and those limits will continue to expand. Some few folks will self-limit themselves and they don't tend to stick around very long anyway, but others will continue to train and find ways of accommodating any limitations they may have.