Though there have been some studies on the benefits of inversion, there's still a lot of research to be done. If you read reviews on Amazon, YouTube, and other sites, you will find thousands of stories from people using inversion tables and chairs to deal with sciatica, lower and middle back pain, as well as other health issues. Please note the following before you purchase an inversion table or chair:

• Talk to a physician first before you start inverting. It can be risky for those with any of the following issues or conditions: back or heart issues, during pregnancy, hiatal and ventral hernias, spine issues such as degenerative discs, arthritis, inner ear issues, glaucoma, hypertension, taking anticoagulants, a history of stroke, carotid artery disease, or any issues that can be exacerbated by higher blood pressure (such as glaucoma and even pink eye).
• Don't use boots that you attach to a bar. It takes a lot of ab strength to get out of position (people get stuck), and it's not necessary or recommended to be inverted 180 degrees immediately.
• Beware of cheap tables. Cheap tables are usually less comfortable on the ankles, harder to control, and harder to get out of.
• For those with ankle, knee, or hip issues, look at inversion chairs vs. tables. Inversion tables will elongate the ankle, knee, and hip joints, and if you have arthritis or joint pain in any of these areas, we recommend an inversion chair that will provide traction just to the spine and not the other joints. These are also easier to get out of and control, so they're recommended for older and less athletic users.

1. Start with a test inversion. If you've been cleared by your doctor to invert, it's still smart to invert for a short period of time at a smaller angle to make sure that it won't be causing you pain in your back, knees, head, or heart. Personally, inverting at too great an angle used to cause shooting pains in my lower back.
2. The first time you invert, it's a good idea to have someone in the room with you to make sure you're able to return to the upright position. We've heard several stories about people getting stuck upside down! This is especially possible with gravity boots (they have hooks on the back of them, and you attach them to a bar), but also with lower quality inversion tables.
3. Experts often recommend that when you invert, you don't necessarily need to go to 180 degrees. According to the work of Dr. Alf Nachemson, 60 degrees is as far as you have to invert to get a 100% reduction of pressure compared to when you're standing.
4. While inverting, if your table has bars on it, you can use those to brace yourself and stretch, twisting yourself from one side to the other. You can also press your lower back into the back of the table repeatedly. Some people will alternately bend their knees to help open their hips. I personally will use my hands to pull my head to one side and then the other, stretching my neck.
5. You can gradually increase the time you stay inverted, but doing it more often is more effective than longer periods of inversion. In the beginning, maybe you'll invert for 30 seconds, and you can gradually increase up to 5 minutes or more. But according to a study by LJ Nosse, inverting causes your muscles to relax by 35% within the first 10 seconds.
6. One chiropractor we spoke to recommends inverting for a period, going back to upright, then doing another round of inversion. He says this will help train your brain and body to retain the benefits longer.

If you're experiencing muscle guarding, which is when a muscle will tighten up as a type of defense mechanism to protect an area that has been injured, then inversion isn't going to be effective in that area - it will prevent traction or decompression because the muscle is holding everything together. One option is to use a heating pad before you invert to help the muscle release.

Most people use inversion tables and chairs for lower back pain. You may have heard that you are shorter by the end of the day - this is due to gravity. Sitting for long periods in poor posture, running, and moving around can misalign your spine and reduce the space between vertebrae. Inversion is supposed to increase the space between vertebrae, allowing increased circulation of blood and spinal fluid, and to reduce pressure on nerves as well as reducing inflammation. It also relaxes tense muscles.

There's an interesting study by Dr. Alf Nachemson, a pioneer in spine care from Sweden and co-editor of SPINE, where volunteers had a pressure sensor implanted in the third lumbar disc. He found that sitting in poor posture can increase the compression of your spine by 250%! When lying down, the pressure was reduced by 75%. The only way to reduce pressure on your vertebrae to 0% is inverting to a 60-degree angle.

Another study was funded by Volvo Aero Corporation of Sweden. In 1987 there were 14 million paid sick days for lower back pain in Sweden, which was costing the Swedish company $570,000 per year. The researchers did a 12-month study with employees who had lower back pain using the Mastercare inversion table (one of our top picks). They found that regular gravity inversion helped relieve lower back pain. They then announced to their employees that if they don't use an inversion table at work every day, they'd have to pay for most of their health benefits. The first year after this was implemented, hours of missed work dropped by 55%!

The Sheffield study, from 1964, involved 175 patients with severe back pain that prevented them from working. After eight inversion treatments, 155 of the patients were able to return to work.

The US Army Physical Fitness School has determined, after six years of research, that soldiers who invert regularly suffer fewer joint-related injuries and back muscle pain and heal more quickly from joint compression damage.

Although there is some positive research on inversion for back pain, there hasn't been extensive research on whether inverting is beneficial or not. If you read Amazon reviews, you will see a lot of inversion tables with hundreds and even thousands of positive reviews. Many of the reviews will claim that inversion has worked wonders for themselves or a family member or friend. The main benefits are usually for people with sciatica, lower back pain, and poor circulation.

Sciatica

Researchers from Newcastle University in the UK have concluded that inversion therapy is an effective conservative treatment for sciatica to avoid surgery. The patients in the study from 2003 to 2006 were all candidates for surgery due to sciatica back pain resulting from a herniated disc. The patients were divided into two groups, one group did regular physiotherapy and the second group did physiotherapy and used inversion tables (they used a Teeter, which is one of the leading inversion table manufacturers and one of our top choices). Those who did physiotherapy plus inversion were 70.5% less likely to require surgery. Of the group that received physiotherapy only, 78% still needed to have back surgery. Only 23% of those who received inversion therapy still needed surgery. Professor David Mendelow, Head of Neuroscience at Newcastle University, told the London Telegraph that he estimates that inversion therapy could save about $160 million per year in unnecessary surgeries in the UK.

Better Brain Function

Inverting is also supposed to help with circulation to the brain, increasing the flow of oxygen and nutrition, which is supposed to increase concentration and memory. According to Dr. Robert Martin, author of "The Gravity Guiding System: Turning the Aging Process Upside Down," the brain operates 14% more accurately when you're inverted.

Dr. Karen Koffler, Director of Integrative Medicine at Northwestern University, says that inversion therapy increases brain health by increasing blood flow. She states, "If there is increased blood flow to the area, there will be increased bioavailability of oxygen and glucose, the two most important metabolic substrates for the brain."

The author of the Da Vinci Code, Dan Brown, inverts every day to fight writer's block and increase his mental clarity.

Though there may be less interest in funding research for inversion because it may offer a lot of people an alternative to pharmaceutical drugs, I would love to see some research on inverting and ADHD.

Insomnia

The decreased muscle tension from inverting is supposed to help those who have trouble sleeping. Famous biohacker and the author of "The 4-Hour Workweek," Tim Ferriss, has recommended six things for faster and better sleep, and one of those things is inversion.

Depression

Rosie O'Donnell announced on "The View" that she suffered from clinical depression and inverted for 15-30 minutes per day to heal her depression.

Reduced stress

A study on inversion, by Physiotherapist LJ Nosse published in 1978 in the Archives Of Physical Medicine and Rehabilitation, concluded that inverting reduces muscle tension by 35% within the first 10 seconds.

Maintaining height

As people age, they tend to lose height because the cartilage between their joints is reduced, osteoporosis sets in, lean muscle mass decreases, and they can have poor posture. Inverting may help with a few of these causes.

Lymphatic drainage

Your lymphatic system is basically the drainage system of your body composed of lymph nodes, vessels, ducts, as well as the spleen, thymus, adenoids, and tonsils. The proper functioning of the lymphatic system is critical to our body's ability to detoxify, drain fluids, regenerate tissues, and maintain a healthy immune system. When your lymphatic system isn't draining properly, you'll get a buildup of waste and toxins, which leads to a weaker immune system and a wide range of health issues. Symptoms of poor lymphatic drainage include:

• stiffness, especially when you wake up
• swollen glands
• chronic sore throat, colds, and ear issues
• lack of mental clarity
• water retention
• itchy and dry skin
• cold hands and feet

Since there is no pump to drain your lymphatic system, lymphatic drainage is done by exercise, lymphatic massage, deep breathing, laughing, drinking lots of water, inverting and twisting poses in yoga, and inversion. The idea is to pump lymph back to the heart, where it will join the blood supply in the vascular system. Dr. David Coulter, a professor at Minnesota and Columbia University, wrote a book explaining in detail how yoga drains the lymphatic system called “Anatomy of Hatha Yoga: A Manual for Students, Teachers, and Practitioners.”

Other Benefits

Inverting has also been reported to help with poor digestion, mood swings, slowing the aging process, improving circulation, reduced varicose veins, improved waste removal through better lymphatic drainage, reduced PMS, and increasing immunity.

If you want to see a 70-year-old walk on his hands the length of a football field, check out the video of Dr. Robert Lockhart! He's a fruitarian and a big advocate of inverting and does the entire interview upside down!

I have been experimenting with inverting for years. I started with a really cheap inversion table that a friend of mine let me borrow. It was hard to get back up to the upright position, and I didn't have any back pain at that point, so I didn't stay with it.

A few years later, I bought gravity boots because they were cheaper, and it looked like it would be a great ab workout. Though I had been doing martial arts for many years and was very athletic, it was really difficult getting the boots on the bar overhead while the boots were on (feel free to stop reading and visualize that for a second). Even more difficult is unhooking the boots off the bar after you're done with your inverting or ab workout (now imagine trying to pull yourself up and unhook the boots with tired abs). I think the boots are a disaster and I'm not surprised every time I hear about someone getting stuck upside down and having to wait until someone walks into a room to help them out.

I graduated to a more basic inversion table that worked fine, and for a few years I've been experimenting with inverting and not-inverting to see the difference with my back pain. I can now absolutely tell the difference - inverting reduces my back pain and seems to keep me in better posture. I understand that it isn't usually associated with reducing neck pain, but one of my standard procedures while inverted is to stretch my neck. The stretching feels easier while upside down, and I can also tell the difference in my neck and upper back.

Several years ago, my chiropractor did x-rays and said that my S1 and L5 vertebrae were starting to fuse. He recommended that I do things to decompress my spine so I could possibly slow down the fusion. He recommended that I do a posture that he called "angry piano," where I lay on the floor on my stomach, reach my arms out as far as I could and hook my fingers to the floor as if I was playing the piano. I told him that I own an inversion table, and he said that would be even better.

I do have bad knees as well, and occasionally when I invert, I get a little bit of pain in one of my knees. I'm still trying to figure out how to improve my knees, and I haven't made the same progress I have with my back. If this pain increases, I will buy an inversion chair.