With one quarter of U.S. adult men and one third of adult women experiencing lower back pain in 2009, according to the Centers for Disease Control, it's no wonder people turn to alternative methods of treatment to relieve symptoms. One recent therapy is the use of inversion tables, with one manufacturer reporting a 374 percent growth in sales between the late 1990s and 2007, as reported in the Chicago Tribune. The use of inversion tables has potentially serious side effects, however, and may not be appropriate for everyone.
Basis
Inversion therapy involves having your head lower than your feet, and the most popular approach is the use of an inversion table. The device is typically made of a metal frame with a shallow seat that you strap yourself into and then tilt slowly backward until you're in an upside-down posture. Some models require you to do this manually, but the more expensive models have motorized controls. According to the Mayo Clinic, proponents claim that inversion can take gravitational pressure off the nerve roots and disks in your spine and increase the space between vertebrae, providing pain relief.
Temporary Effects
Being inverted for only a few minutes can cause your heartbeat to slow and your blood pressure to increase. One study in the American Journal of Optometry and Physiological Optics from 1984 found that inversion led to a mean increase in blood pressure from 110/77 mm Hg before therapy to 130/90 mm Hg afterward. This same study measured a mean increase during inversion in interocular eye pressure from 16.4 mm Hg in the right eye and 15.9 mm Hg in the left eye to 34 and 31 mm Hg, respectively.
Long-Term Effects
As of January 2011, there have been no studies investigating the long-term effects on the body from using inversion therapy. John Morenski, M.D., with the Division of Neurosurgery at the University of Missouri-Columbia, notes that during inversion, the brain suffers from increased pressure, and the degree of head elevation can also significantly affect blood flow. He adds that it seems "reasonable to suspect that the brain will suffer from decreased venous return, at least with chronic use."
Long-term use will also increase interocular eye pressures, which can lead to glaucoma.
Conclusions
Due to the increases in interocular eye pressure during inversion, Dr. Thomas R. Friberg and Dr. Robert N. Weinreb concluded in a study published in March 1985's Journal of the American Medical Association that, if you have glaucoma, diabetic retinopathy, macular degeneration, sickle cell retinopathy or other eye disease, you should refrain from using inversion. The Mayo Clinic Online also cautions that you should avoid inversion therapy if you have cardiovascular disease. Manufacturers of inversion tables often include a long list of potential contraindications, so it's generally a good idea to check with your health care provider before beginning an inversion table regimen.
References
- Mayo Clinic Online: Does Inversion Therapy Relieve Back Pain? Is it Safe?
- Chicago Tribune: Inversions Gain Traction; Julie Deardorff; 2007
- PubMed: American Journal of Optometry and Physiological Optics
- Journal of the American Medical Association": Ocular Manifestations of Gravity Inversion
- Teeter Hang-ups: Contraindications
