I'm someone that actually has had severe back pain. I herniated my L5 disc while sliding in a bobsled. At one point I had greatly diminished plantar flexion from this. A few years later I tore some of my fascia and erector spinae muscles in my left lower back that put me on the floor, literally, 3 days unable to move. So I know about lower back pain. At times I still get pretty uncomfortable if I'm not smart with my training and lifestyle.
There is a story of a professor that asks students to put rock into a jar. Without going deep into the story, the point is to fill the jar with the big rocks first. Take care of the big steps, then worry about the smaller minutia.
So what are the big rocks of back pain?
1. Breathing. Learn to use the diaphragm
2. Hip Mobility. The correct amount of hip mobility is essential if you want to avoid repeated lumbar flexion.
3. Hip Hinge Pattern. You must have a hip hinge pattern that happens without thinking about it. Hinge at the hip, not the lower back. This is the basis for all lower body weight lifting. Sitting in a chair. Etc.
4. Get Rid of Bad Exercises. Quit the small things that create irritants in the body. If you move poorly in the hips, rapid Burpee's are an irritant. If you have a flexion intolerant spine, crunches are not advised.
5. Bracing. Learn to brace when you lift something. Big belly. Not draw the belly in.
These 5 big rocks can literally change your life when you practice them and own them and let them become how you move and live.