It's an odd paradox - it seems the more we find out about back pain, the less we know about it. Here's a run-down of nine key issues, including how your chair and work environment factor into your likelihood to suffer from this mysterious ailment.

1. Back pain is as mystifying today as it ever was. Despite excellent tests and procedures, back specialists admit that up to 80% of all cases have no clear physiological cause. In fact, it's not uncommon for pain-free people to show bulging or herniated discs in x-rays.

2. Also, despite everything we know about back pain, 90% of us are going to have a disabling episode at some point in our lives. How I envy the other 10%!

3. Strength, fitness, and back x-rays are not good predictors of which people will develop back pain. According to one major study, the only predictors were whether the person has had back pain before (no kidding!) and whether the person smokes cigarettes. I'm glad I'm not the one who had to pay for that research…

4. At least we know for certain that people who sit for long periods are at risk for developing back disorders. The two greatest problems sitting in unhealthy positions and sitting in the same position for too long.

5. So it's really important to move around and have more than one comfortable sitting position. In addition to helping the muscles relax and recover, this alternately squeezes and unsqueezes the intervertebral discs, which results in better filtration of fluids into and out of the cores of the discs. Discs stay plumper and, in the long run, healthier.
Hence the need for an ergonomic chair. (And I know just the place to get one!)

6. The most important chair adjustments are:

• Seat height from the floor -- the feet should be able to rest flat on the floor. (However, this doesn't mean the feet should always be flat on the floor. Legs should be free to stay in different positions).
• Depth from the front of the seat to the backrest -- you should be able to use the backrest without any pressure behind the knees.
• Lumbar support height -- every person is shaped differently.

7. The 'proper' chair adjustments and chair posture are influenced tremendously by the rest of your work area. In particular, your eyes can affect posture if your work material is too far away, too low or too high. And your hand position can also affect the whole rest of your body, particularly the posture of your upper back and neck.

8. Speaking of the upper back and neck, discomfort in these regions is often related to upward viewing angles (is your monitor above your eye height?) or leaning, twisting, or reaching.

9. For all of you with chronic, difficult back pain, all the above rules are optional. Each back pain case is different. Rules for prevention or treatment of medium-level cases may be completely inappropriate for severe cases. So before accepting any advice (even mine) listen to your body and trust the advice of your own discomfort reactions.