My mom suffers from back pain a lot. She usually sucks it up if it's not bad, but it got really bad last Monday. She doesn't exactly cope with it tbh. I guess you could say for her is that she's just very active some days and inactive on most other days. Her back usually isn't much of a problem for her every time. It's really hard to explain it because I'm not in her shoes, so I can't vouch for her, you know?
However, I do get back pain myself every now and then. See... I have poor posture. This makes me back hurt a lot unless it's resting against something like a computer chair or pillow. It's probably not nearly as bad as what you deal with... but I do have it on occasion. I've tried to maintain good posture, but because of my weight... it puts a lot of pressure on me, and I end up slouching back down again into poor posture.
This is unrelated... but I have weak shoulders too. It's mostly in my right shoulder because often times, I have a lot of problems with it. If I'm doing too much repetitive movements or motions at a time (typing doesn't count), then it can cause me severe pain and often times discomfort. No one knows what's wrong with my shoulder, but if you put your hand on it while I move it... you can hear it crackling a little.