I have the feeling I’ve always had a weak back.
Some 4 months ago I started working out regularly. Now I can almost touch the floor with my hands without bending my knees.
While doing this exercise I heard a small crack on my back, nothing serious.
Since then I can lift weights easier than before but my back still hurts a bit. My back doesn’t hurt as much after coming home from work, which was normal before.
What else could I do to have a stronger back?
It depends on the cause of your back pain so I agree with the people who said maybe see a doctor. Some people have weak back muscles so strengthening exercises help. My back pain was caused by tight hamstrings and overuse of my back, so I fixed it with a lot of hamstring stretches and getting out of my office chair as much as possible. My brother in law has a bulging disc so neither of those things would help him.
Probably the biggest help for me was WFH so I could get out of my office chair - I can lie down, walk around, or sit in different chairs when I’m taking a break, and I take a lot of breaks. I stretch my hamstrings after most workouts so I’m warmed up. I bend over to touch my toes with my feet together for 90 seconds, starting gently, breathing as I relax, and slowly increasing the stretch a little as my muscles loosen up. Then I take a 30 second break, then I move my feet to somewhere width apart and do another 90 second slow hamstring stretch. Another 30-second break, then I put my feet about halfway to a split and do a other 90 seconds touching the ground. Then a break then as wide as I can go and bend over to touch the ground. I think the slow process really helps me relax.