Humm, I inserted a video here but it will not load so any hoo- what it illustrated was good chairs for chair yoga, and not so good chairs for chair yoga. When we go to a site to teach we often do not have a lot of choice in what type of chairs are in the building. The best chairs, in my opinion, are sturdy banquet chairs that hold up to 400 or 500 pounds, do not have wheels and if needed, they should be stackable. Most people do not want chairs with arms, like those conference chairs with skinny arms, the arms get in the way. But in the case of wheel chairs, lock the wheels, and work around the arms. If you show up to teach chair yoga and all the chairs have wheels check and see if the wheels lock (like wheelchair wheels).