In this video Dr. Stephen Graham, the owner of Graham Chiropractic, explores the virtues of the inversion table.  Dr. Graham talks how the spine during a typical day with sitting, walking, running will push out a portion of the water content of the disc. He reports that research shows that at the end of a day most people are just a little shorter than they are in the beginning of the day.  This is because of the water lost from disc compression.  At night as we sleep the disc rehydrates, which is how we get our height back.  However, Dr. Graham says that scientific studies report that a small fraction of the water content lost never comes back. This is one of the reasons why most people lose height with age.

Dr. Graham talks how the inversion table, by flipping you upside down, will help capture that fraction of water content that was lost.  The idea that by being inverted will have exhibit a negative pressure on the disc and will draw in the fractional bit of water that otherwise would be permanently lost.

Dr. Graham, however, warns that if your back is unhealthy from things like advanced arthritis, disc rot, scarred tissue, and or herniations, it may flare up the condition. In other words, Dr. Graham says, the risk may outweigh any benefit. He goes on to say that inverting at 30 degrees, rather than 60 or the full 90 degrees may be a happy medium.