If you sit a lot sometimes your lower back and your neck can hurt. You can correct that by adjusting the position of your pelvis.
First, notice how if you are sitting right on top of the ‘sitz bones’; the two bones of your butt. If you tend to sit forward of these bones, it arches your lower back creating pressure there. But if you tilt your pelvis back a bit you will find yourself sitting up nice and straight and your stomach engages to support your back. This will correct the overarch in your low back.
Some people sit forward when they get excited or focused into the computer or a book, etc, or when they are trying to sit up really tall. You actually want to pull your stomach in gently and sit back right on the sitzbones.
If that doesn’t take the pressure off the lower back then you can gently tuck the pelvis under (curling the tailbone slightly under) to support the lower back a bit more. This takes pressure off the neck and shoulders.
Happy sitting! 🙂