Is Vibration Safe?

There is mounting scientific evidence, through both animal and clinical studies, that low-level, mechanical signals, delivered using vibration, can stimulate bone formation, prevent fat formation, and promote maintenance of a healthy adult stem cell population.

By way of clinical potential LIV is currently being tested for efficacy as treatment for a range of diseases and disorders including osteoporosis, obesity, and diabesity (diabetes with obesity as the principle cause).

However, just because some vibration may be beneficial, not all vibration is the same and more vibration is not necessarily better.

Before beginning any form of vibration therapy, it is important to consider WHAT type of vibration the device is delivering.

The low intensity vibration signal delivered by the Marodyne device is considered safe for up to 4 hours of exposure per day according to the International Safety Organization threshold for human tolerance of vibration, ISO 2631.

It is important to emphasize that although this low-level intervention is considered safe and beneficial, other frequencies and amplitudes may cause damage to bone and connective tissues, and many amplitudes of vibration are considered pathogenic to the musculoskeletal (e.g., vertebral disc, cartilage, ligament, tendon), neurovestibular, and cardiovascular systems. One should always be concerned that "too much of a good thing" may be true in mechanical stimulation, as well. Just because one aspirin is good for you, doesn't mean that you should take 50 aspirin per day.

There are a multitude of products on market that advertise the benefits of Whole Body Vibration (WBV) – most of which are delivering a very high magnitude signal.

Please note that our research has no relationship whatsoever with the technology or claims made by whole body vibration plates used for exercise and physical training such as Galileo and Power-Plate etc. The magnitudes used in those devices, well in excess of 8.0g, are well beyond the limits recommended for human tolerance by ISO and OSHA, are 35 times greater in amplitude than those mechanical signals that we study, are inherently dangerous, and to our knowledge, show little if any evidence that their devices are safe for bone, cartilage, muscle, tendon, ligaments or any of the major organs.

Low Intensity Vibrations are Safe, High Intensity Vibrations are Hazardous

The great majority of research has focused on attenuating the transmissibility of whole body vibration to the skeleton, with the widely held presumption that high frequency vibrations are pathogenic to the musculoskeletal system16-18. In cases where vibration is inevitable7, exposure limits have been recommended by agencies focused on occupational hazards, such as the National Institute of Occupational Safety and Health, (NIOSH), Centers for Disease Control (CDC), and the International Organization for Standardization (ISO)17.

Levels of vibration are typically considered as a function of magnitude (g-force), frequency (Hz) and duration of exposure (time). One "g" is equal to earth's gravitational field, or an acceleration of 9.8 meters per second per second. Frequency corresponds to the number of cycles delivered per second.

High intensity devices are those that deliver a g-force of greater than 1-g, regardless of the frequency.

Most devices are engineered such that the higher frequency signals correspond to high magnitude signals as well.

With g-forces that exceed this level, acute discomfort arises not only from focal pain in muscle and joints, but from induced alterations in visual perception and tracking. As early as 1938, researchers have reported discontinuities in visual activity between 25 and 40 Hz for whole body vibration (WBV) and at some acceleration levels, vibrations above 20 Hz temporarily diminished patellar reflexes.

Conditioned athletes, should they knowingly understand these dangers and still wish to put their body at risk is one thing, but to use such interventions on the elderly, osteoporotic, or functionally impaired individuals is dubious, at best.

In contrast to concerns for the use of vibration that exceeds 1g, it should also be pointed out that no adverse effects were observed in any of the preliminary trial with humans which kept vibration below 0.3g13-15. Certainly, considering the demonstrated risk to so many physiologic systems, if functional disorders compromise an individual's ability to protect themselves, it is clear that vibration that approaches 1g should be studiously avoided.

Contraindications and Potential Dangers of the Use of Vibration

Before considering vibration as an avenue of intervention for osteoporosis, obesity, or any other therapeutic application, it is important to consider the benefits of vibration versus the potential risks and complications of use.

High intensity vibration can be exceedingly dangerous, and is an etiologic factor in several pathologic conditions including

  • low back pain1
  • neurovestibular disorders2
  • Raynaud's syndrome3

Industries such as transportation and construction4, as well as the military5, are working towards minimizing occupational exposure to these potentially hazardous mechanical stimuli.

Frequently Asked Questions:

What do you believe would be the potential short-term and long-term risks, if any, of using vibration to "treat" musculoskeletal conditions?

You have to remember that the principal reason scientists study vibration is because of the potential HARM it can do. Vibration is considered one of the principal pathogens in the high incidence of low-back pain in truck drivers and helicopter pilots, and is notorious for causing circulatory dysfunction in the extremities in occupations that use hand-held machinery. In other words, vibration is potentially very dangerous indeed, and should be approached with caution.

It is because of this concern that OSHA and the International Safety Org (ISO) have come out w/ specific advisories on duration thresholds for human tolerance, which is dependent on both frequency and duration. In the figure, below, from ISO-2631, it shows frequency (bottom), and acceleration (vertical), w/ the dark "hockey-sticks" indicating how much time you can safely be exposed to these signals.

  • >10g vibration Galileo PowerPlate Nemes
  • 0.3g vibration Marodyne LIV

ISO 2631-1:1997: Daily Exposer Limit

How do I determine if a particular device is a High Intensity or Low intensity device?

To determine the difference between the beneficial low intensity vibrations that have an extensive history of safety, and are generated by the Marodyne device versus the dangerous high intensity devices, there are several factors to examine.

Levels of vibration are typically considered as a function of magnitude (g-force), frequency (Hz) and duration of exposure (time). One "g" is equal to earth's gravitational field, or an acceleration of 9.8 meters per second per second. Frequency corresponds to the number of cycles delivered per second.

High intensity devices are those that deliver a g-force of greater than 1-g.

A large body of research has demonstrated that high frequency (5 to 100 Hz), high magnitude vibration contributes (and in some cases CAUSES) low back pain following extended exposure7 and circulatory disorders such as Raynaud's syndrome3.

Ignoring such dangers, g-forces that greatly exceed 1.0 are the very basis of devices such as PowerPlate and Galileo and should be approached with extreme caution.

I'm assuming that 0.3g at 30Hz is still much lower than the lower-vibration setting on the Power Plate, Galileo or other "fitness" whole body vibration (wbv) devices? Is this true?

Yes, the Marodyne device delivers a signal many orders of magnitude less than most WBV devices currently on market. Refer the figure below to mark where 30Hz (cycles per second) is, and where 0.3g shows up, indicating four hours of safe exposure each day. There is also placed a mark where "PowerPlate" and others are, in which the devices generate well over 10g...based on this graph, you should not subject yourself to any more than one second of such g-force on any given day! So, if your musculoskeletal system survives PowerPlate, there is some likelihood that there will be some long term damage. In answer to your question, 0.3g, the work we do, is 50x less, at least, than the Powerplate and other whole body vibration plate type devices.

Safety: Exposer Limits for Humans

Published Articles

  1. Transmission of Vertical Whole Body Vibration to the Human Body
  2. Platform Accelerations of Three Different Whole-body Vibration Devices and the Transmission of Vertical Vibrations to the Lower Limbs
  3. Mechanical Signals as Anabolic Agents in Bone
  4. Mechanical Signals As a Non-Invasive Means to Influence Mesenchymal Stem Cell Fate, Promoting Bone and Suppressing the Fat Phenotype

References

  1. Anderson JA, Otun EO, Sweetman BJ 1987 Occupational hazards and low back pain. Rev Environ Health 7:121-160.
  2. Seidel H, Harazin B, Pavlas K, Sroka C, Richter J, Bluthner R, Erdmann U, Grzesik J, Hinz B, Rothe R 1988 Isolated and combined effects of prolonged exposures to noise and whole-body vibration on hearing, vision and strain. Int Arch Occup Environ Health 61:95-106.
  3. Dandanell R, Engstrom K 1986 Vibration from riveting tools in the frequency range 6 Hz-10 MHz and Raynaud's phenomenon. Scand J Work Environ Health 12:338-342.
  4. Bongers PM, Boshuizen HC, Hulshof CT, Koemeester AP 1988 Back disorders in crane operators exposed to whole-body vibration. Int Arch Occup Environ Health 60:129-137.
  5. de Oliveira CG, Simpson DM, Nadal J 2001 Lumbar back muscle activity of helicopter pilots and whole-body vibration. J Biomech 34:1309-1315.
  6. Griffin JJ 2001 Handbook of human vibration.
  7. Bongers PM, Boshuizen HC, Hulshof CT, Koemeester AP 1988 Long-term sickness absence due to back disorders in crane operators exposed to whole-body vibration. Int Arch Occup Environ Health 61:59-64.
  8. International Standards Organization 1985 Evaluation of Human Exposure to Whole-Body Vibration. ISO 2631/1:
  9. Coermann R 1938 Untersuchung ueber die Einwirkung von Schwingungen auf den menschlichen Organismus. 73-117.
  10. Goldman DE 1948 The effect of mechanical vibration on the patella reflex of the cat. Am J Physiol 155:79.
  11. Roll JP, Martin B, Gauthier GM, Mussa IF 1980 Effects of whole-body vibration on spinal reflexes in man. Aviat Space Environ Med 51:1227-1233.
  12. Dupuis H, Hartung E 1980 Einfluss von Vibrationen auf die optische Wahrnehmung. Research Report Wehrmedizin BMVg-FBWM 80-10 1- 141.
  13. Ward K, Alsop C, Brown S, Caulton J, Adams J, Mughal M 2001 A randomized, placebo controlled, pilot trial of low magnitude, high frequency loading treatment of children with disabling conditions who also have low bone mineral density. J Bone Miner Res 16S:1148.
  14. Pitukcheewanont P, Safani D, Gilsanz V, Rubin CT 2002 Short Term Low Level Mechanical Stimulation Increases Cancellous and Cortical Bone Density and Muscles of Females with Osteoporosis: A Pilot Study. Endocrine Society Transactions in press:
  15. Recker R, Rubin C, Cullen D, Belongia D, Ryaby J, McLeod K 1997 Non- invasive biomechanical intervention for the prevention of post- menopausal osteopenia. J Bone Miner Res 12:S242.
  16. Bernard B, Nelson N, Estill CF, Fine L 1998 The NIOSH review of hand-arm vibration syndrome: vigilance is crucial. National Institute of Occupational Safety and Health. J Occup Environ Med 40:780-785.
  17. Griffin MJ 1998 Predicting the hazards of whole-body vibration--considerations of a standard. Ind Health 36:83-91.
  18. Wilder DG, Pope MH 1996 Epidemiological and aetiological aspects of low back pain in vibration environments - an update. Clin Biomech (Bristol , Avon ) 11:61-73.