I dunno. They're really comfortable. I haven't sat on them for more than about 2 hours in one go, but my experience with them has been good so far. One thing t

I dunno. They're really comfortable. I haven't sat on them for more than about 2 hours in one go, but my experience with them has been good so far. One thing though, the one I've used isn't a rocking chair; it has wheels instead. The rocking may make a difference.