Astronauts get more intervertebral disc herniations when they come down to Earth, probably because the darn things swell up in zero-G. We’re used to thinking about disc herniation as something that happens because of gravity … not because it’s absent! I’m sure most of us probably assume that taking the pressure off is nice for spines (and maybe it is while you’re still floating around).
But apparently discs get a bit poofy and unstable if you don’t keep the pressure on ‘em.
And … every time herniations come up, it’s important to emphasize that they are an over-rated problem. Of course they occur, and make some people miserable, but their severity and clinical importance has also been blown way out of proportion for decades.