I have had on and off lower back issues for years, which culminated in a required visit to a chiropractor where, much to my surprise, he actually put pressure on one point of my hip for 30 minutes with his elbow and it was like I was a new man. Had nothing to do with my actual back, hip was pulling on the muscles.
Now, chiros are always a temporary fix... they alleviate the problem but the issue is present and will come back. I started fixing my own back because I remembered where he pushed and was able to get rid of the muscle pain whenever it seized up on me, but that's super annoying and the issue was coming up more and more often and I was in a lot of discomfort.
Wanting to improve my situation, starting a month ago, I started doing a set weights routine with a different body focus each day (working Mon/Tue, cardio Wed, working Thurs/Fri... Sat/Sun are also rest/stretch/cardio days depending on what kind of shape you're in) and there are some back-related exercises in that routine... and ever since I started doing this routine, my back is brand new, I have never felt better. It's all to do with strengthening your back muscles as far as I can figure (barring you having a herniated disc or something wrong with your bone structure that is).
I am a 9-5 office worker, slouchy sitter, pretty active and I am not overweight (6 feet, 180lbs) just for reference. If you're interested, this is the program I am doing.. note that there is a dedicated "back" day but also some back-related exercises on other days too the lower body days like the hyperextensions and cable woodchoppers especially... the first time I did this, it felt like someone had spent all night punching me in the kidneys, no mobility issues, just "bruised" feeling... but once my muscles acclimated, I was feeling 100x better almost immediately. This routine may seem like a lot, but you can bust each one out in half an hour if you're motivated. If you don't know what an exercise is, I recommend YouTube... Scott Herman Fitness is a good guy for proper posture and moving if you can deal with his constant shirtlessness
Also, FWIW, I crack my back all the time... I don't believe it has a negative effect on you. My back actually stops cracking if it does seize up, I always knew I was in for a solid week of pain if my back stopped cracking.
Monday – Back
Weighted pull ups: 4 sets of 4-6 reps
1-arm dumbbell row: 2 sets of 4-6 reps
Seated cable row (preferably with wide-grip): 3 sets of 6-8 reps
Lat pull down – 3 sets of 8-10 reps
Cable crunches – 3-4 sets of 10-12 reps
Tuesday – Chest
Incline press: 4 sets of 4-6 reps
Dumbbell bench press: 3 sets of 8 reps
Cable crossover – 2 sets of 10-12 reps
Face pulls- 3-4 sets of 8-10 reps
Wednesday – Rest
Rest. Stretch. Do some soft tissue work. Optional cardio.
Thursday – Lower body
Deadlift – 3 sets of 4-6 reps
Lunges – 2 sets of 6-8 reps per leg
Leg press – 3 sets of 10-12 reps
Calf raise (seated or standing) – 5 sets of 10-15 reps
Hyperextension – 3 sets of 10-12 reps
Cable woodchoppers – 3 sets of 10-15 reps per side
Friday – Upper body
Seated dumbbell press – 3 sets of 6-8 reps
Weighted pull-ups – 3 x 6-8 reps
Cable crossover – 3 sets of 10-12 reps
Side delt raises – 3 sets of 10-12 reps
Rear delt raises – 2 sets of 10-12 reps
Barbell curl – 3-4 sets of 8-10 reps
Overhead tricep rope extensions – 3-4 sets of 8-10 reps