Whole-Body Vibration (WBV): Effectiveness, Safety, & Side Effects
Are you a woman looking to prevent bone loss and osteoporosis? Or are you a fitness buff who wants to build bone density faster than can be done with exercise alone?
If you are either, here’s the most recent piece of advice from experts: junk the vibrating devices and stick to good old-fashioned exercise.
New findings show that the whole-body vibration (WBV) platforms used by fitness buffs and older women to build bone density or prevent bone loss from osteoporosis may be just expensive junk—and may even pose health and safety hazards for elderly people with fragile bones.
After menopause, women frequently experience progressive bone loss or develop osteoporosis, both of which cause their bones to become brittle and porous and place them at increased risk for bone fractures. Men also suffer from progressive bone loss, but at lower rates.
In the United States, osteoporosis affects two percent of men and 10 percent of women over the age of 50. Forty-nine percent of older women and 30 percent of older men in the US have osteopenia or low bone density.
Weight-bearing exercise—or any exercise, including walking, dancing or exercising with small weights, where the feet and legs support the body’s weight—increases bone mass the same way that exercise increases muscle mass.
When stress is placed on the bones, the bones respond by becoming thicker and stronger, and around 10 years ago, WBV platforms were first developed to build bone density by mimicking this action of exercise. The platforms produce tiny up and down vibrations, making muscles contract and putting tiny stresses on the body.
Over the next few years, a number of animal and human studies showed the compact platforms could increase bone mass. Since then, WBV platform therapy has been increasingly touted as an alternative or supplement to drugs or hormone treatment used to prevent bone loss in older women.
A slew of vibrating machines have also popped up in fitness clubs, and the Globe and Mail reports that NASA has even considered using this technique to maintain the bone-health of U.S. astronauts during long-duration space flights. Many companies now market WBV devices at around US$200 to US$3,000.
But consumers should note that the U.S. Food and Drug Administration has not approved these devices for medical purposes.
What’s more, it’s still unclear if the vibration devices actually work to increase bone mass—and a new study showed they don’t.
No difference in bone loss
The Canadian clinical trial, published in the November 15, 2011 issue of the Annals of Internal Medicine, found that the platforms didn’t work: Older women who stood on a WBV for 20 minutes a day suffered just as much bone loss over the course of the year-long trial as women who didn’t use the platform.
“To our disappointment, we did not find an effect from vibration therapy in these post-menopausal women,” says Dr. Angela Cheung, the study’s senior researcher.
“Although researchers are seeking alternatives to time-consuming exercise to improve bone density, the results of this study suggest this specific therapy is not effective in improving bone density,” says Dr. Cheung, who is also director of the osteoporosis program at the University Health Network in Toronto.
The UHN is Canada’s largest hospital-based research program with major research in complex care, cardiology, transplantation, neurosciences, oncology, surgical innovation, infectious diseases, genomic medicine and rehabilitation medicine.
There are different types of vibration platforms. Some produce low magnitude vibrations while others produce high magnitude ones. Some WBV are designed to exercise on, while others are meant to be used by simply standing on them.
The platforms in the Canadian study were low-magnitude devices, about twice the size of a bathroom scale, and designed for women to stand on.
For the year-long trial, 202 healthy postmenopausal women from around Toronto, Canada were recruited. Most of them around 60 years old and all suffered from low bone density, but not low enough to have osteoporosis. None of them was taking prescription bone medications.
The participants were randomized into three groups. Two groups of women were given platforms to use at home for 20 minutes a day. One group received platforms that vibrated at 90 Hz and the women in the other group were given platforms that vibrated at 30 Hz. The remaining group of women received no platforms. All women in the study were give calcium and vitamin D supplements.
At the start and end of the year, researchers measured the bone structure and bone density of all the women at the hip and lumbar spine, and forearm and lower leg.
The researchers found that there was no difference in the bone densities and bone structures of women from all the three groups and women in all three groups showed small losses in bone mass in the hips, spine and shin.
Health and safety problems
A review of 75 studies on the vibrating devices by the U.S. Agency for Healthcare Research and Quality (AHRQ) showed that there was not enough scientific proof to show that WBV therapy could prevent and treat osteoporosis.
Worse, the long-term use of these vibrating platforms posed health and safety hazards, the AHRQ concluded in its review.
“Little scientific evidence evaluates the benefits and harms of whole-body vibration therapy for the prevention and treatment of osteoporosis,” concluded the review, which was published as a technical report in November 2011.
“Vibration exposure, therapeutic and occupational, presents safety concerns,” the report warned.
“Vibration has been recognized as an occupational hazard associated with low back pain, musculoskeletal problems, cardiovascular disorders, neurovestibular disorders and Raynaud’s syndrome.”
It also pointed out that the ISO 2631-1 defined high intensity vibrations—those that produce more than 1g force—as hazardous regardless of frequency. The ISO, the world-recognized developer of industry standards, set these vibration limits for comfort, performance proficiency, and safety based on the known occupational hazards.
Whole-body vibration therapy may cause plantar fasciitis, itchy legs, blurred vision, tinny hearing (tinnitus), white-finger disease (a secondary form of Raynaud’s syndrome), orthostatic hypertension, and aggravation of soft-tissue and joint injuries.
Use of WBV devices may dislocate the intraocular lens of a person who has had cataract surgery. This is distinct possibility, the AHRQ said, since the elderly people who use vibrating devices are also those who are at greater risk for cataract.
Other safety concerns raised over the use of WBV platforms include:
- It’s possible people using the platforms could lose contact with the vibration platform and become air-bound when acceleration exceeds 1 g.
- The resulting impact as the feet return to the platform may be harmful for individuals with fragile bones.
- Older people could even lose balance altogether and fall when using the platform.
- Vibration may also be harmful to the soft tissue organs of the head and chest.
- By simply shifting position, a person may make it difficult to make an accurate measurement of vibration in different parts of the body, since the transmissibility of vibration to the head and trunk can be altered by flexing the knees and posture .
- WBV-induced vibration at frequencies higher than 20 Hz may be amplified to unsafe levels by resonant frequencies of different body parts, as body parts produce a resonant vibration to match that of the WBV.
Danger was also posed by “the potential inability of consumers to clearly distinguish low-intensity platforms intended for osteoporosis therapy from platforms intended for high intensity exercise,” the AHRQ said.
The technical report also said there “unknown long-term harms from the use of whole-body vibration therapy.
The AHRQ said that without further research, manufacturers couldn’t claim that whole-body vibration therapy was effective for the prevention and treatment of osteoporosis.
It also noted that, because the FDA has not approved WBV platforms for medical purposes, there are now no standards that regulate their manufacture, and designs vary widely.
The technical report reviewed 75 studies, culled from a comprehensive search of all studies on the vibrating devices that could be found using a grey literature search of Federal Government websites, the FDA websites, ClinicalTrials.gov website, presentations of unpublished studies at scientific meetings; an Internal search using different engines (e.g., Google Scholar, Scirus, LexisNexis); a survey of enrolling and ongoing clinical trials; as well as scouring through the CSA Physical Education Index, the Web of Science and Medscape databases to find studies that were presented in scientific meetings.
The agency also searched through published literature in several databases: MEDLINE, via OVID and via PubMed, the Cochrane Library, AMED, CINAHL, the CSA Physical Education Index, the Web of Science, PEDro, and Academic Search™ Premier.
Exercise, calcium, vitamin D
For women looking to prevent bone loss, Dr. Howard LeWine, Chief Medical Editor of Harvard Health Publications has this to say: exercise, calcium and vitamin D work good enough.
“To get the best vibrations for your bones, shake them on the dance floor or a walking path in your neighborhood, not on a vibrating platform that moves while you stand still,” he says.
Dr. Levine also advises:
- “Engage in whatever exercise works for you, he advises, saying that weight-bearing and resistance exercises are best.
- Get enough calcium and vitamin D—about 1,200 mg of calcium each day. Because few foods contain vitamin D, I recommend to my patients that they take 1,000 IU of vitamin D3 daily.
- Don’t smoke. Smokers lose bone faster than nonsmokers, and have higher fracture rates.
Dr. Leung of the Canadian study agrees. For women without osteoporosis, she says, adequate calcium and vitamin D through diet and supplements, as well as weight-bearing exercises are better strategies for maintaining strong bones.