I suggest looking at the book Back Mechanic by Stuart McGill. After nearly 50 years of on and off low back/hip spasms and pain I was better in 2-3 days of starting to follow his approach. He helps you identify triggers for back pain and how to avoid those triggers. And much more. Totally worked for me. Not saying my problem was the same as yours but his approach is widely applicable. He has been interviewed many times on youtube and so on but his book really lays it out. BTW a major source of my various muscular-skeletal type problems came from extreme stretching as a teenager.