Wave Vibration Therapy Might Make Sense in Theory but Does It Work?

Introduction

Wave vibration therapy (also known as whole body vibration) refers to a type of physical therapy which is believed to exercise muscles via stimulating neuromuscular reflexes. Confusing? Put another way, a machine or platform shakes the body which in turn activates a cascade of events - muscles contract and nerves fire. This in turn affects bones and maybe even hormones. That's the theory anyway.

The key here is that the person does not actively initiate the movement of their muscles. This is done by the whole body vibration device. In a nutshell, a work-out without actually doing the work. I can't say 'a work-out without moving a muscle' as the muscle does actually move. Just not under the conscious control of the person.

It is promoted as a weight loss and work-out hack so that people can exercise less and achieve more. It is also supposed to help diabetes, osteoporosis, balance and muscle power.

Why am I so interested?

It is quite common for doctors to leave medicine to pursue other careers. I have many ex-doctor friends who are unreasonably successful (and rich) while following their dreams. Two of my friends are currently crowdfunding for some crazy version of a whole body vibration machine. Of course, I will support them as friends.

But will my support just be because we are old friends or do I actually believe in the science of whole body vibration? Time for another 'unboxing blog'.

What Is Wave Vibration Therapy?

Wave vibration therapy refers to a type of physical therapy which is believed to exercise muscles via stimulating neuromuscular reflexes. A seminal paper in 2000 defined vibration exercise as 'a new muscular training method which is used in athletes and in the prevention of osteoporosis' (1).

Essentially, someone stands (or sits) on a vibrating plate which moves up, down and all around at different angles. The movements are small (4 - 8 mm) but rapid. The body senses the movement, perceives it as instability and immediately tries to correct the imbalance.

This triggers the superfast muscle fibres (which are one of the three types of muscles fibres in the body along with fast and slow). Superfast muscle fibres are inefficient at using energy. This is potentially a good thing if you are trying to loose weight as triggering the superfast muscle fibres will burn a lot of calories. The vibrating plate moves again. The body moves to re-establish equilibrium. The supports muscles fire. Essentially, it's a 'rinse and repeat' process for several minutes. Again that is the theory.

The seminal paper mentioned above gives us some insights into the mechanisms of wave vibration therapy.

In this paper, investigators explored the physiological mechanism of fatigue in 37 healthy young subjects who exercised to the point of exhaustion. The subjects also underwent two vibration exercise sessions. Whole body vibration exercise elicited a cardio-reactive response, which was believed to be due to neural, and muscular mechanisms of fatigue. This suggests that wave vibration therapy somehow acts at both a neuromuscular level and at a cardiac level. This science supports the overall philosophy behind how whole body vibration is supposed to work.

The FDA has approved a number of whole body vibration machines for use in medical practice. NASA are testing different types of whole body vibration machines too. (Those dropout friends of mine are probably advising NASA).

There are 25 whole body vibrations products for sale on Amazon costing up to $250 and there are 180 in different types of books on the topic.

That leaves us with a conceptual framework for how this machine might work, a philosophy supported by science and high level interest in the idea. This still begs the question - does it actually help any health related conditions?

Is There Any Research?

There are 1941 publications relating to wave vibration therapy which includes 442 clinical trials. The first formal publication on the subject dates back to 1958 and came from the aviation industry (2).

Relatively speaking, wave vibration therapy has a poor research track record. As an example, physiotherapy has almost 160,000 publications and 26,000 clinical trials to back it up.

I reviewed the published research for this blog and even watched some very cheesy infomercials (pitiful doctors in scrub suits trying out wave vibration therapy) to get a full picture of these new gadgets.

Work Related Whole Body Vibration

Whole body vibration is probably best known in times past as a risk related to some occupations which were associated with specific work related injuries e.g. lower back pain (3). To be fair, these people were probably exposed to higher levels of vibration and for longer periods of time as compared to therapeutic whole body vibration.

Does Wave Vibration Therapy Improve Balance?

A single researcher dominates this field of research. The research was done in a methodical way (with each study building logically on the results of the previous study) allowing us to actually reach some conclusions. There are three main studies of interest to us from this single investigator plus one additional study from a WHO collaborative group.

Study 1

Torvinen, a Finnish investigator carried out randomized crossover study in 16 young healthy volunteers (4). The volunteers underwent four minutes of whole body vibration using a tilting platform or a sham intervention, in a randomized order on different days. A  battery of six tests were carried out just before, immediately after and 60 minutes after whole body vibration or the sham intervention. These tests included stability platform, grip strength, isometric lower limb extension, tandem walk, vertical jump, and shuttle run.

As compared to baseline, there was a statistically significant improvement in muscle performance, and body balance at the two minute follow up but not at the 60 minute follow up in the wave vibration arm of the study. At no time point were improvements seen in the control group.  The overall conclusion of the study was that a single bout of whole body vibration transiently improves muscle performance of lower extremities and body balance in young healthy adults.

Study 2

In the next study, Torvinen, evaluated the effect of a 4-month whole body vibration-intervention on muscle performance and body balance in young, healthy, nonathletic adults (5). The whole body vibration arm of the study involved 4 minute sessions on a vertically standing platform 3-5 times per week for four months. This time a total of five performance tests (vertical jump, isometric extension strength of the lower extremities, grip strength, shuttle run, and postural sway on a stability platform) were performed initially and at 2 and 4 months timepoints.

As compared to controls, jumping power improved in the young study subjects which suggests neuromuscular adaptation to the vibration stimulus (which is a good thing). However no effect on dynamic or static balance was noted in the subjects. Torvinen recommended that whole body vibration be compared to conventional resistance training. That was in 2002.

Study 3

One year later, Torvinen and colleagues published the results of an 8 month whole body vibration intervention study on bone, muscular performance, and body balance in young and healthy adults (6). The study design was similar - 56 subjects who had vertical whole body vibration for 4 min/day, 3-5 times per week. (I think it may have been a continuation of study 2). The same five performance tests were used alongside DXA bone scanning and testing for markers of bone turnover.

As such this study overlaps with some of the topics that we will cover later, but needs to be addressed here as it directly relates to balance.

The vibration intervention did not improve balance. No effect was noted on any of the performance tests (apart from vertical jump height). No effect was noted related to the mass, structure, or estimated strength of bone at any skeletal site.  The 8-month vibration intervention had a good safety profile.

I could not find any more studies from Torvinen and I am unsure if he/she ever got around to the wave vibration theory versus resistance training study.

A 2005 study from WHO collaboration center investigated the affects of whole body vibration in an elderly population (7). The study population included 42 elderly volunteer nursing home residents. Subject participants were allocated to either physical therapy, or physical therapy plus whole body vibration for a total of six weeks. There were statistically significant improvements in the vibration group for gait score, body balance, and 'timed up and go' test (TUG)  as compared to the control group. (Ask the parents of toddlers or teenagers about how difficult 'TUG' can be but that's another story).

This study is highly relevant, as it has the potential to reduce the risk of falls and injury in elderly patients. Approximately 40% of people over the age of 75 fall each year, which has a significant cost and impact on quality of life in this population.

Bottom Line

A good quality systematic research program failed to show any benefits of vibration therapy on balance in young subjects. A WHO study group found benefits of vibration therapy in older patients. How do we reconcile these two different results when both study groups are reputable and designed their studies carefully? I am not sure. One possibility is that vibration therapy benefits older people more than young people- but this is just a guess?

Does It Improve Muscle Power?

Discussing muscle power next builds logically on the previous section on balance.

The first Torvinen study showed some transient benefits of wave therapy on muscle power. The second and third study did not.

Let's move from Finland to Italy where another investigator enrolled 6 females who played volleyball at national level (8). Having established baseline parameters, each study participant had one leg randomized to whole body vibration and the other leg randomized to a control arm (please forgive the terrible unintentional pun). Statistically significant enhancement of the experimental treatment was noted for the average velocity, average force and average power (P < 0.05-0.005).

Back up north to Scandinavia we go for more answers.

Scandinavian investigators did a systematic review of vibration therapy for muscle strength and jump performance (9). A total of 12 relevant studies were identified. Only five studies had an adequate design with a control group performing the same exercises as the wave vibration therapy group. Analyzing the data from these studies showed that no difference in performance improvement was found between groups.

Bottom Line

The science is inconclusive but overall seems to suggest no benefit of whole body vibration for muscle power.

Does It Prevent Osteoporosis?

Bone studies build logically on research on balance and muscle power. Animal studies have shown that whole body vibration therapy in growing mice can prevent bone resorption (10). Canadian investigators carried out a systematic review and meta-analysis of the effect of whole body vibration on bone mineral density (11).

The analysis looked at 8 trials and found small (but significant) improvements in bone mineral density in postmenopausal women and children and adolescents, but not in young adults.

Malaysian investigators also conducted a systematic review of whole body vibration in the prevention and treatment of osteoporosis (12). The results were published in a Malaysian Journal in 2016 and whittled down 276 initial studies to just 9 (based on quality and relevance). They found that whole body vibration machine is a good adjunctive therapy for the prevention and management of osteoporosis in postmenopausal women but cannot be recommended for men at this time.

Bottom Line

Wave vibration therapy may help postmenopausal women with osteoporosis but has not been shown to be effective in young adults or older men.

In 2000, a study from an Italian investigator studied the effect of whole body vibration treatment on blood hormone concentrations (13). The study participants were 14 young male adults. The study participants were exposed to one minute sessions of whole body vibration. A total of 10 of these one minute sessions were carried out.

The subjects performed a series of exercises before and after the whole body vibration therapy. Blood samples were taken, and showed a significant increase in testosterone and growth hormone, and decreases in cortisol. An increase in neuromuscular also effectiveness was noted.

This means that whole body vibration resulted in two separate outcomes -  change in endocrine profile and increase in neuromuscular effectiveness. The authors hypothesized that a single underlying mechanism of action (as yet not defined) may explain the two phenomena.

Bottom Line

One study (albeit from a researcher with a real interest in whole body vibration) shows that whole body vibration does modulate hormone levels. It is unclear at to what the downstream effects of these changes might be. This study was done in young men and as such the results may bot be relevant to older men or women of any age.

Does it help with Diabetes?

There are over 30 published studies on whole body vibration and diabetes.

Luckily for us, there is a Chinese meta-analysis of the data of these studies (14).

The overview included the data from 4 trials and involved 154 study participants. The study just focused on the effects of whole body vibration on physical function in diabetes and found insufficient evidence to conclusively recommend whole body vibration for physical health in diabetes. Unfortunately the study did not comment on other key issues of interest such as glycemic control.

Another systematic review and meta-analysis (from Brazil) evaluated the effects of wave vibration therapy on blood glucose levels and cardiovascular risk factors in patients with type 2 diabetes (15).

Here is the funny part. The reviewers identified 585 potential articles but only 2 of those studies were considered to be suitable for inclusion in the meta-analysis. Imagine 2/585.

The analysis found that wave vibration therapy improved glycemic control when combined with exercise. However it could not be ascertained from the studies included whether the effects were due to exercise alone, wave vibration therapy alone or the combination. A non-significant decrease in BMI was noted was observed with wave vibration therapy. The data on lipids was positive in one study and negative in the other study. Let's be serious- two studies does not a meta-analysis make.

Let's go back to those 30 studies again ourselves.

The most relevant of the 30 studies was a Spanish study which looked at 50 non-insulin dependent diabetic patients who were randomized either  an intervention group that, in addition to standard care, received a 12-week whole body vibration intervention, or a control group receiving only standard care (16).

There was a statistically significant reduction in fasting glucose, HbA1C,  cholesterol, triglycerides and atherogenic index in the intervention group as compared to the control group.

Anther study looked at whole body vibration on balance, muscle strength, and glycosylated hemoglobin in 55 elderly patients with diabetic peripheral neuropathy (17).

The study participants were randomly assigned to one of three groups:

whole body vibration with balance exercise group,

balance exercise group or a

control group.

The whole body vibration involved  3 × 3 min, 3 times per week, for 6 weeks. Statistically significant improvements were noted in the static balance, dynamic balance, muscle strength, and HbA1c in the whole body vibration group as compared to the balance exercise only and to the control group (P < 0.05).

Bottom Line

Some individual studies have shown a benefit for  wave vibration therapy for glycemic control in diabetes. However,  one meta-analysis (with just two studies) had positive results but could not disentangle the effects of wave vibration therapy from exercise. The jury is still out on this one.

Is Wave Vibration Therapy Safe?

For quite some time, it has been recognised that workers with whole body vibration exposure are at risk of a range of medical conditions including spinal injury, neuromuscular disease and end organ damage (18).

In some countries, certain injuries caused by WBV is recognised as an occupational disease and may be compensable. However, wave vibration therapy is tailored to give a less intense exposure and over a shorter duration of time.

Overall, studies on wave vibration show that it is safe and well-tolerated (although there are very few studies, with small patient number and are usually short-term studies).

As the overall rates of gastrointestinal disease appear to be higher in people exposed to while body vibration, Japanese investigators evaluated this relationship formally and found that whole body vibration slows gastric motility in healthy men (19). This lends credence to a possible risk of gastrointestinal disease related to whole body vibration. It also makes sense. The body usually shuts off digestion in the face of a perceived threat. Repeated loss of balance (which is who the body interprets whole body vibration) is perceived by the body as a threat.

There is probably no better place to monitor safety than an ICU.  Heart rate, oxygen saturation and blood pressure were measured.

Twelve intensive care unit patients and 12 healthy subjects using whole-body vibration for the first time were examined while lying in bed. No clinically significant side effects were noted in either group.

The theory behind wave vibration therapy seems to make sense. The problem is that there is remarkably little published research on the effects of wave vibration therapy. There is even less published research on positive health benefits of wave vibration therapy. The little research that we have hints at the possibility of differential effects in different patient demographics.

Will I support my ex-doctor inventor friends? Yes I will support them, but with the caveat that they do high quality research on wave vibration therapy prior to developing any prototypes.

Unless NASA have some top-secret classified data showing that wave vibration therapy rocks (literally and metaphorically), wave vibration therapy will have to be classified as theoretically plausible but clinically unproven.

References

3. Annual incidence of non-specific low back pain as an occupational disease attributed to whole-body vibration according to the National Dutch Register 2005-2012.
Kuijer PP, van der Molen HF, Schop A, Moeijes F, Frings-Dresen MH, Hulshof CT.
Ergonomics. 2015;58(7):1232-8. doi: 10.1080/00140139.2014.915991. Epub 2014 May 13