Your abdominal muscles support your back. Keeping them toned helps keep your spine aligned - improves posture and therefore prevents weakening of the spine, further injury, spinal stenosis, and acquired scoliosis. Keeping the spine aligned also keeps the nerves aligned.
I'll repeat this one because it helps a lot with alignment - find a way to hang upside down at a 45 to 80 degree angle, feet at the high end, head at the low end. Do that for at least 5-10 minutes once or twice a day. While doing this, it should feel a little bit like traction...gently stretching/pulling your spine into alignment. I used an inversion table but if you can't get one or don't have something like it, a padded slant-board is ok, and you can hang by the backs of your knees instead of your feet. You can buy slant-board or build one.