San2006, Dr. Sutter talks mostly about prolonged inversion. Maybe he would think a couple of minutes of full inversion would be just fine. I don't know.
I know inversion has been done forever. If I didn't have such a messed up back, I wouldn't be so cautious. But then, having a bad back may be all the more reason to do it, if it could help.
Again, I just need to research to decide what's best to do. I do appreciate your help. I had definitely decided to not fully invert anymore, but that may have been a bad decision.
I get tired of having to do so much research on everything, but you got to do what you got to do. :)