The late science fiction writer Robert A. Heinlein once wrote a book entitled The Moon is a Harsh Mistress. That may well be, but for back pain sufferers, the phrase 'Gravity is a Harsh Mistress' — here on Earth — seems a tad more relevant.

Gravity is a force that continuously stresses us from the moment we are born, pulling on our muscles, our bones and joints, and our ligaments.

And because we stand upright, something — according to many scientists — our bodies may not be completely evolved or designed to do, the part of our bodies that is most adversely affected by gravity is often our spines.

The discs between our vertabrae are a bit like shock absorbers, but as gravity combines with muscle imbalances, or stressful positions, or past or recent injuries, it creates considerable spinal compression as the rough and tumble of the day wears on.

Inversion has been around for thousands of years, and the inversion table is generally safer than some other inversion methods.

The inversion table is also very cost effective when compared to some other forms of back pain therapy since you pay the cost for the table only once for, generally, many years of use.

Many back pain sufferers say the inversion table is one of the best back pain therapy resources available. Some say they could not get through most days without it.

But there are some caveats you should be aware of.

You need to be in reasonably good health before trying inversion, and you should be careful to get a table appropriate to your height and weight. Also, if you don't have much upper body strength, especially in your arms, you should probably consider a motorized table. You should have someone standing by the first few times you use it to be sure you are not going to experience too many difficulties. And don't try to go all the way upside down for a while. Start with a small degree of inversion and when you are sure you are comfortable with it, gradually increase it over several days, or even several weeks. Finally, keep an eye on the condition of the table and maintain it well. Don't assume the table will take care of itself. Most are sturdy enough to make you think nothing could go wrong, especially when they're new, but you shouldn't allow yourself to get into the lazy habit of taking it for granted. You should always make sure the table is in good condition and in good working order, every time, before trusting it with your health.

Back-Pain-Therapy.com recommends inversion as a back pain therapy resource. 

Teeter Hang Ups Power II GL Inversion Table Silver – $ 1399.00 Power II GL Inversion Table by Teeter Hang Ups. Deluxe model with motorized inversion ability. Ul classified heavy duty inversion table with standard ankle clamps, owner's manual and Better Back, Better Body Book. Gravity Lock ankle clamps.

Teeter Hang Ups Power II Inversion Table White – $ 1199.00 Power II Inversion Table by Teeter Hang Ups. Deluxe model with motorized inversion ability. Ul classified heavy duty inversion table with standard ankle clamps, owner's manual and Better Back, Better Body Book.

Teeter Hang Ups Power II Inversion Table Silver – $ 1199.00 Power II Inversion Table by Teeter Hang Ups. Deluxe model with motorized inversion ability. Ul classified heavy duty inversion table with standard ankle clamps, owner's manual and Better Back, Better Body Book.

Teeter Hang Ups Power II GL Inversion Table White – $ 1399.00 Power II GL Inversion Table by Teeter Hang Ups. Deluxe model with motorized inversion ability. Ul classified heavy duty inversion table with standard ankle clamps, owner's manual and Better Back, Better Body Book. Gravity Lock ankle clamps.

Pro Max Inversion Table – $ 799.00 The Health Mark Pro Inversion Table helps to stimulate blood flow to release stress, compression fatigue and lower back pain. Designed for face-up or face-down inversion, the table can be used by massage therapists, or any home user.

Teeter EP-950 Inversion Table – $ 399.00 Brand new model featuring "Flex" technology bed, the EP-950 inversion table from Teeter Hang Ups combines the ease of use of their deisign with industry leading quality. Comes with Free shipping and MFG warranty, free DVD and book.

EP-550 Inversion table – $ 299.00 The brand new Teeter Hang Ups EP-550 Inversion Table features "flex technology" which allows the back rest to bend. With simple arm movements (rotation is accomplished by shifting the weight of the arms), the table easily rotates to any comfortable angle. The smooth rotation allows for oscillation and intermittent traction. Adjustable roller hinges allow you to pre-select three levels to control the aggressiveness of rotation, and the tether strap allows you to pre-select the maximum angle of inversion. Comfortable ankle clamps hold you securely while inverting.