Ironically, the only lower back problem I have is when standing up or walking for extended periods of time - like full day events and the like. Always had that, for as long as I can remember. o.O
Some people get lower back pain from sitting the way people usually do in a chain - that is, with a curved back, supported by the chain in the mid region. General recommendation is to sit straight, as if (or actually) not using the chair back at all, even when actually using the back rest. The chair needs to fit rather well for that to work properly, which is the motivation behind the ludicrous amount of adjustments on quality office chairs.
Haven’t really any lower back problems from sitting down myself, but for various other reasons, I replaced my office chair with a piano bench. (Lack of space, and an office chair is not great for piano or cello playing, so… priorities. ) So, I literally have to sit straight, for obvious reason. Either way, still not having any problems, so at least, it doesn’t seem worse than an office chair.