My friend was in Japan recently and saw this on TV.
chiba-u.ac.jp/research/coe_...
They call it a "walkable chair", they should work on the name, but the braces hold your legs rigid so you can stand without putting any thought into balance into it, then it is flexible enough to let you walk, and if you lean back, you can sit down in mid air.
I just YouTubed it, and there are plenty of vids, maybe you all know. One link is some rival, by the name it looks German.
Nice, baggy pair of trousers. You can clump about in these.