Doc - I stumbled across these demos answering a question about dimel dls, but I got to wandering around the site and saw the Stability Ball Reverse Hypers:
http://www.midwestbarbell.com/videos/revhyperball.wmv
It looks like it might be a decent substitute for the reverse hyper machine for those of use who don't have access to one, but I'm wondering if you think it will have the same benefits as the machine (as far as getting fluid back between the vertebrae) since the ROM at the bottom appears to be different.
Since you're a back expert, what do you think?