An actual academic who takes a rigorous, logical approach to identifying and remedying back problems while also addressing very down to earth issues like how best to sneeze, tie your shoelaces or or lift light objects from the floor in the best way possible for your back.

He's got some books, I've got the one called "Back Mechanic" which I highly recommend and you can find him mentioned in various blogs and YouTube channels.

He also does work with high end athletes, powerlifters etc. which may be of interest to some, but I found too much of that kind of thing while researching and it was his more down to earth advice that I found very useful. In particular his "McGill big 3" excercises for strengthening core back muscles.

His website is a little cheesy but don't let that put you off, lots of great info in his books.

https://www.backfitpro.com/backpain/

Also, walking (though McGill has some more specific hints on walking posture).