My back flaired up when I was 30 and in response to the pain, I moved less and walked less. And it got worse.
Then there was a hike I really wanted to do (a few mile day hike), I did and I felt better. Ah-ha!
Over a few months, the more I walked, the better I felt. Now (age 50), if I get a hint of back pain (too much computer time, snow shoveling or lifting something badly), I stop that activity and I get in more walking miles. And that's avoided any recurrences for me. YMMV.
My theory is that we are not descended from sedentary people - they got eaten by saber-tooth cats. We're descended from people who moved around in search of food and sometimes had to pack and travel long distances.
Imaging backs is tricky. Oh, lots of ways to do it, but if you look at an old back, you see what looks like problems. But older people with and without any back pain have similarly alarming looking scans. (this from my MD wife).
I know anything offering relief is tempting, even surgery. And some back surgery helps, but not nearly with the efficacy of surgery of gallbladders, appendices or cancer. I'd exhaust all lifestyle and exercise options first. Keep a log of activity, non-activity and back pain. Look for patterns and do more of what helps.