After reading these posts, I'm feeling like a million-bucks right now!! I've never thought of chiro, having anybody walk on my back. I don't even have an "easy chair" (e.g. Lazy-Boy type).
To be sure, riding a ZTR is much more demanding than it appears. Every lawn is full of holes, ditches, bumps, and every other thing that makes the ride rough. I continue to be surprised at how much jostling my body takes when riding. I've don this for many years, and now have past 72. Maybe I just don't know any better.
I grew up on a farm and spent lots and lots of hours on a small tractor as a kid -- first time over after plowing heavy clay soil. Those rides were tough, but I think the ride on the ZTR isn't much different.