Hanging upside down for an extended period of time in order to relieve spinal ailments is called inversion therapy, and has been practiced globally for hundreds of years. The practice fluctuates in popularity, but with magician David Blaine's 60-hour inversion stunt, it seems to be back on the rise.
The first record of inversion therapy dates back to approximately 400 B.C., when Hippocrates used ropes and a harness to pull his patients upside down as a way of relieving back pain. Centuries later, in the 1960s, Dr. Robert Martin introduced the "Gravity Guidance System" to the American public. The system focused on gravity's affect on the body and posture. In the 1970s, Dr. Martin released a book outlining the system, with an accompanying inversion table. In the 1980s, inversion therapy was dealt a blow when it was reported that the therapy may put users in danger of stroke.
Studies have indicated that hanging upside down can have some positive effects. It is most often used to relieve back pain by increasing the space between the vertebrae. Additionally, muscular tension in the back and shoulders can be lessened using this technique, as well as an improvement in posture and circulation. According to Dr. Jerry Swanson, however, inversion therapy has no known long-term benefits for back pain.
Hanging upside down inherently has many serious health risks. When inverted, the heart must work much harder to get blood to the legs and feet. Blood then begins to accumulate in the head with no where to go, and begins to pool in the brain, risking clotting and death. Pooling also can occur in the lungs, which can lead to respiratory failure.
Inversion therapy can be practiced either on an inversion table or with gravity boots. Inversion tables can be set to any degree the user wishes to be inverted, from fully inverted, to a shallow incline. Beginners are advised to start with a slight incline and work their way up to a steeper incline. Gravity boots are worn on the feet and attached to a rack normally placed on the ceiling. Worn like normal shoes, they allow the user to suspend, or hang, upside down.
Anyone who has heart disease, high blood pressure, eye diseases, spinal injury, hernia, ear infection, or anyone who is pregnant should not attempt inversion therapy without consulting a doctor. Beginners also are advised to have someone accompany them during the exercise.