If sitting creates back discomfort you have a highly sensitized back, or tissue damage, or both. Avoiding this pain trigger will reduce the pain sensitivity.
Sitting causes the low back to flex which is normally not an issue. But modern life has increased sitting time at work, on the road, and at home. Soon sitting at the computer becomes uncomfortable. We call this the flexion intolerant back. Specific low back tissues become stressed and sensitized, in particular the spine discs and ligaments. Sitting upright to restore the natural curves to the spine relieves this stress. But it “costs” in terms of muscle work resulting in those muscles to tire and allow the spine to slouch. This increases disc and ligament stress. Reducing stresses in the back associated with sitting not only makes sitting more comfortable, but it helps build more capacity for pain-free movement throughout the day. The objective is make sitting a dynamic activity with frequent posture change and support the natural curve of the low back.