What sitting posture is good for dealing with back pain?

A good sitting posture for dealing with back pain is an “active” posture, meaning the position of the spine should be kept natural and relaxed but with a slight forward curve near the low back to keep your lower back supported. The best way to do this is by following these simple steps:

1) Sit up straight, so that your buttocks are at the very end of your seat and not resting on it. Keep your feet flat on the floor or use a foot rest as needed.
2) Relaxed shoulders - we often forget about keeping our shoulders in line when we sit down; make sure they're not rounded forwards or elevated towards our ears!
3) Align hips and knees - try to maintain 90 degree angles at these joints. If that isn't comfortable then you can use a cushion or small pillow behind you for extra lumbar support.
4) To stay comfortable without slouching, take regular breaks from static postures throughout the day (even if it's just standing up to stretch), switch sides if necessary (use both arms while typing/using devices etc.) , and avoid any positions which cause discomfort in your body over time.

By following these tips you will improve your overall comfort level while sitting, reduce stress on spinal structures caused by poor postural habits, decrease muscle soreness in areas such as neck & upper back, and help promote healthy spinal curves which protect against future injuries associated with prolonged sitting sessions!