Whole Body Vibration Therapy for Bone Health

[TomBAvoider]

I just got the message that the machine shipped. Meanwhile, I came across a chart showing various exercises one might perform on a WBV platform - for some reason the pdf would only open in Firefox for me, and not in Safari or Chrome (probably it's easiest to just download the pdf):
 

http://www.thenoblerexk1.com/documents/k1positions.pdf

 

Maybe some of us can find inspiration in some of these exercise positions.

Edited June 2, 2016 by TomBAvoider

[Todd S]

TomBAvoider,

 

Thanks for the exercises chart.

 

I've only had the vibration plate for a few days, but I can provide some comments already.

 

I replaced my Soloflex platform with the vibration plate where I do my morning handstand. Yesterday I tried the 'strong' mode [5 mm amplitude] and top speed [20]. It works fine, except that it makes a very noisy rattling sound before I put my weight on it by kicking up into a handstand. [i worried about whether the noise would be enough to travel to the neighboring townhouse.]

 

This morning I used 'strong mode' and a speed setting of 10. It was great! It was much quieter than at 20 -- and the amplitude of the movement felt really good, especially when trying to push the upper part of my chest out -- while pulling the lower ribs in and holding a solid posterior pelvic tilt -- and while elevating and protracting and externally rotating the shoulders -- to form a very elevated bridge.

 

[The surface of the vibration plate seems a bit smoother than I'd prefer, so I used workout gloves to ensure a secure and comfortable grip.]

 

Todd

Edited June 5, 2016 by Todd S

[TomBAvoider]

Thanks for the feedback, Todd. I guess the thing about WBV being a novel intervention is that there are no real longitudinal studies which could guide us as to what the best protocols are for what the various goals may be. From looking at the studies, some desirable effects happen at one amplitude/g/time and for another quite a different one. But without a track record, all we can do is exchange experiences as users. I therefore intend to experiment and report on my various one-rat results insofar as I can glean them, and I'm hoping to pick up tips and observations from the experience of others - such as yourself. 

[Todd S]

I forgot to mention one cautionary note:  When I first got the vibration plate, I stood on it with just very thin nylon socks on -- and tried 'soft' and 'strong' modes at all the speeds (from 1 to 20).

 

Afterwards, I notice pain at the little toe of my left foot. I realized that I had a broken (internal) blood vessel near one of the joints. My feet get quite a pounding anyway in my aerobics class, so I'm probably more susceptible to this happening than most folks.

 

For a few days, anyway, I'll stick to just hands on the vibration plate.

 

[Edit: my toe recovered quickly.]

 

Thanks,

Todd

Edited June 5, 2016 by Todd S

[TomBAvoider]

Thanks, Todd - that's just the kind of info we should be sharing with each other; I now know to start slow and cautious - maybe even stand in something not quite as thin as socks, but that still fully transmits the vibrations without too much dampening.

[TomBAvoider]

I just received the machine. The vibrations - particularly with the "strong" setting - are quite powerful to my untrained senses. Reading through some of the feedback on this machine on Amazon, it appears some engineers express doubts as to whether the amplitude really is 5mm. There's also a woman who wrote a book on WBV who claims this model does not output enough energy to be therapeutic, but it's also possible she has some kind of conflict of interest. Rather than rely on hearsay, I wonder if there is some way short of taking it to a lab, to measure the claims made on the spec sheet - is it really 2mm, 5mm, and the g forces. I am not super trusting of manufacturers claims, especially dodgy ones made in places like China. Given that we are relying on literature that specifies ranges of vibration, it would be unfortunate to pour a lot of time and effort into it if we are not getting the specs we think we are.

 

Be that as it may, I've been trawling PubMed and came across this rather interesting study (full text):

 

Effects of whole body vibration training on body composition, skeletal muscle strength, and cardiovascular health

 

J Exerc Rehabil. 2015 Dec; 11(6): 289–295.

Published online 2015 Dec 31. doi:  10.12965/jer.150254

 

 

Song-Young Park,1,* Won-Mok Son,2 and Oh-Sung Kwon3

 

 

Abstract

 

Whole body vibration training (WBVT) has been used as a supplement to conventional exercise training such as resistance exercise training to improve skeletal muscle strength, specifically, in rehabilitation field. Recently, this exercise modality has been utilized by cardiovascular studies to examine whether WBVT can be a useful exercise modality to improve cardiovascular health. These studies reported that WBVT has not only beneficial effects on muscular strength but also cardiovascular health in elderly and disease population. However, its mechanism underlying the beneficial effects of WBVT in cardiovascular health has not been well documented. Therefore, this review highlighted the impacts of WBVT on cardiovascular health, and its mechanisms in conjunction with the improved muscular strength and body composition in various populations.

[Sthira]

I'm not sure how much specific amplitude or g-forces would matter here -- just some shakin may be beneficial -- ever notice the well-toned arms and shoulders of otherwise porky Harley Davidson bikers?

 

I'm still awaiting my exciting big purchase! I can't wait to try this thing!

[Dean Pomerleau]

TomB,

 

Thanks for the very interesting review paper. It definitely seems there is mounting evidence of the potential benefits of WBV therapy.

 

Regarding the G-force generated by the machine we've purchased. I too think it seems quite powerful. But quantitatively, you are right that it isn't entirely clear just what the amplitude is, and how much G-force it generates. In fact, contrary to the 2mm & 5mm specs in the literature that came with the machine as shipped to us, this review site shows the VMAX Q2 (which our machine is the white-labelled equivalent of) has an amplitude of 0.5-1mm on the low setting, and 1-2mm on the high setting, with the highest generated G-force of 7.1g. Below is the full chart with our machine on the far left.

 

According to this chart, on it's maximum setting (highest speed and strong amplitude) our machine generates a G-force that puts it right in the middle of the range of therapeutic vibration that I identified in the first post of this thread.

 

--Dean

 

[TomBAvoider]

Thanks Dean for that link. I am somewhat puzzled by it. I agree that the machine we've purchased looks exactly like the Vmax Q2, but the specs are way off in another important way: in the review chart, the movement for Vmax Q2 is classified as "triplanar". Yet the machine sold on Amazon has the movement characterized as "Linear Vibration Type". That's not nearly the same thing. Furthermore, I don't know when that review was written, but the Amazon merchant claims: "New 2016 Model" - is it possible that we are talking about different models that simply look the same? FWIW, I have reached out to the Amazon merchant with a link to the review and a request for feedback regarding the apparent discrepancy. I will report on the response.

[Sthira]

Ok so my vibe platform showed up, and I'm straddling side split on it right now as I jab away at my phone keyboard. It's a wonderful little machine -- every bit as powerful as dance studio version. I plan to use it a hundred different ways -- mostly for gaining more flexibility in some abused bits of me that have tightened through overuse -- shins, ankles, feet, toes. My poor feet -- please help my abused feet, dear vibe platform.

 

I'm thrilled! Great purchase -- thanks for the suggestion, Dean! Hope I don't break it!

[Dean Pomerleau]

Sthira,

 

I'm glad you like the vibration platform. But don't thank me, thank Kenton who recommended it to me. Thanks again Kenton! Regarding breaking the platform, it seems quite rugged and well-built to me. Kenton says he's been using his daily for over a year at least, but probably not quite in the same contorted ways you plan too!

 

--Dean

[Sthira]

Thank you, Kenton!

 

I notice each time I visit my grandparents they seem a little more kephotic. Can I use kephotic as a direct object or adverb for kephosis?

 

Hunching. Age hunches the human back -- in nearly everyone.

 

Becoming hunched I think is a huge problem not just for the aged but for everyone in a computer-using, driving a car, sitting in a chair or even walking, jogging, sprinting... It's our culture. Look around: nearly everyone's hunched. When you see it, it becomes painful in yourself, too.

 

One of the many gifts of a yoga practice may offer is restorative. So many restorative poses may help with spinal mobility problems. This one is not only great for kephosis, but this sweet pose is also for lengthening and opening tight hamstrings, increasing ranges of tight iliotibial bands (joggers, runners, sprinters -- all of them have tight hamstrings, bands, hips, lower backs... Running -- argh...), this pose is great for bound up hip flexors (cyclists, rowers, weight lifters...), grounding the sacroiliac joints (everyone) -- so much -- is this simple, fun pose called in Sanskrit, Viparita Karani. Legs up the wall. You may already do this, I don't know you.

 

It's so very healthy for the body I've heard yogis and dancers call it the "fountain of youth pose..." Whee it's great for your body, lookee:

 

http://www.yogajournal.com/pose/legs-up-the-wall-pose/

 

One way I'm using this vibe machine is in place of a bolster or folded blankets. Push the platform up to a wall, turn it on, I set it to max 20-minutes at max 20 vibration (maybe you're scared), fold a blanket over the hard edge, and lay the thing.

 

If you're interested in doing such a bizarre thing -- I know y'all are haha --, please do follow the safety link above, but sub the vibe platform in place of bolsters.

 

Lay over it carefully, and the bend in your spine shouldn't come from dumping into your lumbar. Listen: your lumbar probably has plenty of flexion -- it already knows how to bend (unless you're really sedentary or injured...) You want your lumbar essentially flat on the vibe platform. The bend in your spine should be just beneath the shoulder blades -- bra strap level -- everyone can relate to where that is?

 

Lift and open your chest. The vibe platform will help release that area, you need release there, I don't know you but everyone needs release there and may not know it -- make your back more flexible. You want this. Breathe on the platform into that hard edge, breathe into those tight spaces that are, I assure you, tightening with age and overuse, and your breathing will deepen and improve. Lengthen your exhales. Expand your chest cavity. You want space there.

 

This position is heaven. Please no pain, but you do want a little discomfort, not too much discomfort, find an edge where it almost hurts, then ease off, it's your body, find just enough discomfort so that you're able to relax, yet slowly regain that glorious effortless spinal flexibility you had as a kid. You'll love this!

 

Losing spinal flexibility I'm convinced is one of many hallmarks of overall aging skeletons. Lower back problems -- nearly everyone I know has them -- often originate in collapsed chest cavities, tight hamstrings and bound up I.T. Bands. This pose, practiced consistently for several minutes a day -- with or without the shaking platform -- may just relieve your nagging lower back pains.

 

Open your upper spine, lengthen your hamstrings, breathe, rest, and you may just find that in time, with patience, with love for the only body you'll ever get in this lifetime (unless exoskeletons are headed our way soon) your nagging lower back pains may ease. May they ease. May you suffer less pain. Relieve lower back pains without NSAID addictions, and you may just find locomotion is fun again. Walking, running, cart wheels, crazy handstands up against trees, high on life and music and sweet love, some reggae, maybe life again may become a new sweeter, maybe handstands in the park in the rain when everyone else is moaning about their poor arthritic bones will become a beautiful joy.

 

Just don't pee in shades of red (unless you're a beet addict, then okie dokie)

Edited June 8, 2016 by Sthira

[Dean Pomerleau]

Sthira,

 

[FYI - it's easy to add an image like the one on the web page you pointed to in your post. Simply right-click on the image and select "copy image address" (or something similar). Then come back to your post, position the cursor where you want the image, and click on the "Image" button on the toolbar - it has an icon that looks like a little Polaroid photo. Then paste the image URL into the box that pops up and hit return. That's it.] 

 

Here is the image of the pose you recommend:

 

 

It looks like it would be good for stretching the back. I think I'll give it a try.

 

But are you serious about doing it on the vibration platform at maximum power! You must be insane. Seriously, don't you worry about that much vibration directly on your back?

 

I was worried when I saw the headline for your red pee post that you might have ruptured a blood vessel with your vibration platform. I was glad that wasn't the explanation, but I'm still worried for your well-being. I know you're flexible and have experience with vibration machines, but don't go overboard with this thing.

 

--Dean

[Sthira]

Haha yeah I have no right click on an iPhone, but yes, a picture a thousand words.

 

Thanks for your concern over my own back. I'm working in my own space. Start slower and more gently -- depends upon time of day. What feels extreme releases over time, and stay safe up there.

[Todd S]

Thank you Sthira for arguments in favor of improving flexibility of the thoracic spine. The related goal for me -- which I may never achieve, but still seems worthwhile working towards -- is the gymnastic bridge, in which the lower body (including the lumbar spine) should be a straight as possible. The shoulders should be above -- or even forward beyond-- the hands. This requires the ability to fully 'open' the shoulders -- as well as flexibility in the thoracic spine. The following sketch is from a wikipedia page on "Bridge (exercise)":

An intermediate version of this is done with feet on an elevated surface -- and requires less flexibility, but can be more difficult to push up into because more bodyweight is over the hands. Another intermediate way to approach it is to start with a back-to-a-wall handstand (not very close to the wall) -- and push only the upper chest out. [The latter is what I'm currently doing on the vibration plate every morning at home. In the gym, I also work on pressing up into a bridge starting with feet on the floor, but I'm thus far not flexible enough to fully straighten my arms.]

 

Todd

Edited June 9, 2016 by Todd S

[TomBAvoider]

We should not let our understandable enthusiasm for the potential of WBV machines get in the way of reason. We have the machines - great, now how do you use them? Do we have evidence-based protocols? Like with any intervention, f.ex. exercise, different protocols are needed for different end points and goals. The trouble with WBV is that there are precious few - if any - truly longitudinal studies that can show which protocols of use are optimal for whatever goals we may have. That's a serious shortcoming. In the absence of well-sourced evidence, we are reduced to having to develop such protocols ourselves, based on speculation and guesswork. And so, I have started the process of developing such a protocol, which naturally has already ballooned well into the territory of yak-shaving.  

 

The first step in developing a protocol is to make sure we're obeying the prime directive "first do no harm". 

 

And yet, in my research I have come across very serious problems that indicate extreme caution should be used with any commercially available WBV machines - the phrase "extreme caution" is not my exaggeration, but comes from a paper I'll cite later. Let us start with something that I personally find quite worrisome: eye and ear damage as a result of WBV on commercially available machines (PMC4671777 : "A great safety concern with WBV is the acceleration transmitted through the axial and appendicular skeleton, and the related potential damage to vision and hearing"). Retinal detachment and small blood vessel damage as a result of vibration is a serious concern, as is irreversible hearing damage from vibration ablating inner ear hair cells (which do not regenerate).

 

The importance of developing safe protocols of use for WBV machines is highlighted by the fact that a lot of the potential vision and hearing damage can be attenuated or avoided with proper posture, and that posture is non-intuitive enough that many users may adopt exactly the worst posture (see the photo of Dean in the first post of this thread).

 

The commercially available WBV machines incorporate settings which are unquestionably extremely dangerous if used for even very short periods of time, according to occupational safety standards developed by the ISO (ISO-2631), such as levels that are seven times higher than what is considered a safe threshold for even one minute of exposure each day (15.1g p-p @ 30Hz) - as summed up in this paper: PMC3688642 , see below:

 

"Conclusions

Vibration can have adverse effects on a number of physiologic systems. This work indicates that readily accessible WBV devices markedly exceed ISO guidelines for safety, and extreme caution must be practiced when considering their use." [my bold: TBA]

 

But how do you know if you are exceeding the safety parameters? It is not as simple as reading your machine's instructions. There are documented problems with commercially available WBV machines where the stated specs do not correspond to the actually measured specs by independent labs - I had a paper which performed a study which indicated up to 25% variance, but I lost it in the blizzard of open tabs (there is one more limited in scope - PMID: 26205764 - only looking at a few machines, though it has a strongly cautionary conclusion: "Based on these results we strongly recommend that user in practice and research should analyse their WBV training devices regarding applied frequency and mode of vibration."). This is why I insisted that we find out if the specs in our machines are anywhere near accurate - this is absolutely vital... meanwhile, the seller I reached out to in regard to the specs controversy has not responded in several days, which is very concerning to say the least (and this is an Amazon seller!). It is no use trying to stay within safe parameters when you can't rely on the stated specs of your machine. Buyer beware - even more so when it comes to your health, not merely wrong specs on the TV you purchased.

 

The critical importance of developing safe protocols of use for WBV machines is highlighted by the fact that you can substantially attenuate possible vibration-induced vision and hearing damage by adopting proper posture. This very subject was examined in this study, that can guide us toward safer use of WBV machines wrt. vision and hearing - PMID: 24081617 - which found:

 

Abstract

 

Exercise vibration platforms are becoming commonplace in homes and fitness centers. However, excessive mechanical energy transferred to the head and eye can cause injury. The purpose of this study was to evaluate how changes in platform frequency and knee flexion angle affect acceleration transmission to the head. Participants (N=12) stood on a whole-body vibration platform with knee flexion angles of 0°, 20°, and 40° to evaluate how changes in knee flexion affected head acceleration. 7 specific platform frequencies were tested between 20-50 Hz at 2 peak-to-peak displacement settings (1 and 2 mm nominal). Accelerations were measured with triaxial accelerometers at the platform and head to generate transmissibility ratios. Platform-to-head transmissibility was not significantly different between the 2 platform peak-to-peak amplitudes (P>0.05). Transmissibility measures varied depending on platform frequency and knee angle (P < 0.05). Flexing the knees resulted in reduced head transmissibility at all frequencies (P<0.05). Platform-to-head transmissibility values exceeded 1.0 at both 20 and 25 Hz platform vibration frequencies with the knees in full extension. To reduce the risk of injury to structures of the head during vibration exercise, using platforms frequencies below 30 Hz with small knee flexion angles (< 40°) should be avoided. 

 

This is just a small taste of the kinds of concerns that should be addressed by any responsible user of the vibration machine discussed in this thread. First do no harm. Then, find the areas of clear benefit apart from safety issues. For example, PMC4519201 finds no benefit for any health-inducing effects on the blood profile of users of WBV:

 

Acute and Chronic Whole-Body Vibration Exercise does not Induce Health-Promoting Effects on The Blood Profile

Anastasios A. Theodorou,1,2 Vassilis Gerodimos,1 Konstantina Karatrantou,1 Vassilis Paschalis,1,2 Konstantina Chanou,1 Athanasios Z. Jamurtas,1 and Michalis G. Nikolaidis3

 

Abstract

 

Whole-body vibration (WBV) exercise is an alternative, popular and easy exercise that can be followed by general public. Therefore, the aim of the present study was to investigate the influence of acute and chronic WBV exercise on health-related parameters. Twenty-eight women were allocated into a control group (n=11, mean ±SEM: age, 43.5 ±1.5 yr; body mass, 66.1 ±3.1 kg; height, 160.6 ±1.5 cm) and a vibration group (n=17, mean ±SEM: age, 44.0 ±1.0 yr; body mass, 67.1 ±2.2 kg; height, 162.5 ±1.5 cm). After baseline assessments, participants of the experimental group performed WBV training 3 times/week for 8 weeks. Before and after the chronic WBV exercise, the participants of the vibration group performed one session of acute WBV exercise. Blood chemistry measurements (hematology, creatine kinase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, C-reactive protein, glucose, insulin, triacylglycerols, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A1, apolipoprotein B and lipoprotein, thiobarbituric-acid reactive substances, protein carbonyls, total antioxidant capacity, uric acid, albumin and bilirubin) were assessed pre-exercise and post-exercise at the first and eighth week of WBV exercise in both control and vibration groups. The results failed to support any effect of both acute and chronic WBV exercise on biochemical health-related parameters. However, it seems that WBV exercise is a safe way of training without a negative impact on muscle and liver functionality.

 

More after further yak-shaving. To be continued.

Edited June 9, 2016 by TomBAvoider

[Todd S]

TomBAvoider,

 

Thank you for the warnings and references. They are interesting to read and think about. From those it appears that the cautionary notes are just that -- without evidence of actual harm.

 

I suppose that a handstand on a vibration plate could expose the head to more vibration than a standing position would, because of the shorter distance between the plate contact point and the head. On the other hand, in a handstand the head hangs from the cervical spine rather than being on top of it -- and so in a handstand the head could be more isolated from the vibration. My personal observation so far is that the amount of vibration I feel in my head varies with how I position my head while in the handstand. And the vibration doesn't seem excessive.

 

Todd

[TomBAvoider]

I'm not sure I'd say there is no evidence. Take PMC3688642 which specifically measured the vibration forces that affect the head subjected to WBV machines. The measurements they obtained far exceeded the standards set in ISO-2631. Those standards in turn were developed as a result of long term multiple studies that showed definite harm from vibration in that range - there is a metric ton of such studies out there (I can cite scads of them, or just go to PubMed and search). ISO would not have settled on those standards in the absence of documented harm - as they always are subject to pushback from industry, so they need to have solid evidence to survive objections. Since those standards are exceeded by commercial WBV machines in use as prescribed, it stands to reason that real harm is not just a theoretical possibility. I don't see any gaps in this chain of reasoning, but I always welcome contrary arguments. 

[Sthira]

Tom thank you for these important warnings. I guess to save my eyes & ears I should stop already with the ten minute headstands on the vibe platform? I'm kidding. They're just five minute headstands....

 

Not really, but I have been using the platform for supported shoulder stands (salamba sarvangasana) Roughly looks like this:

 

https://usercontent1.hubstatic.com/9112472_f260.jpg

 

For me in supported shoulder stand the platform sits upon blocks, and I use it in place of a chair. It feels wonderful on my pelvic floor, sacrum, lower back, inner thighs, hips, IT band... But I do also feel shaking vibration in my head -- teeth, eyes, ears, and instinctively backed the settings down, down, down.

 

I use the machine for my feet, ankles, calves kinda like a massage. Feels amazing on lower extremities -- especially my tight shins. I contort all over this thing -- as intended.

 

I also straddle it -- front splits, side splits, low lunges, "lizard pose" pigeon pose (insanely comfy) I use it to open my quads and hip flexors after bicycling. Feels so amazing! Also I use it for supine virasana

 

http://media.yogajournal.com/wp-content/uploads/MASTER_189_09-credit.jpg

 

This pose supine virasana is amazingly theraputic for knees, calves, shins, feet, quads, resetting the sacrum and literally curing lower back problems. Supine virasana is no secret for us flexy crazies seeking deeper and deeper backbends with proper alignment. (No dumping lumbar)

 

So I'm using the vibe plat in many many ways just like I'd planned.

 

You mentioned something wrong with the picture of Dean standing on it, you posted? Not sure I get your point. Could you explain what's the issue with standing (and he uses SHOES!)? I'm on the platform barefoot (nearly all the time in life I'm barefoot -- I hate shoes -- except when required to wear stinking shoes.... So far I haven't gotten tape worms, knock on wood)

Edited June 11, 2016 by Sthira

[TomBAvoider]

Per  PMID: 24081617 the vibration that might damage vision and hearing is transmitted to the head when you stand with your knees not bent. That's how Dean stands. If you bend your knees 40 degrees you avoid transmitting the full force of harmful vibration to the head. Note however, that we are talking about vibration within a certain range of frequency and g force. You might therefore say "well, it will be safe if you are outside of the harmful parameters", which is valid of course, except you at that point must be sure that your specific machine is calibrated properly, because without independent measurements you cannot be sure and must rely on the manufacturer's/sellers claims, which as studies show are not always reliable (PMID: 26205764). So if you don't know - for sure - your machine's specs, it is just safer to always have your knees bent, regardless of the claimed frequency/g force (unless verified). Unfortunately, the Amazon seller I contacted regarding the specs has not responded. Fortunately, I believe Dean has the capability to solve the problem wrt. our particular model (though that will still not help the problem of possible individual machine variation) - Dean has been deeply involved in the engineering of self-drive cars, and research into self-drive cars involved extensive use of accelerometers, which I therefore surmise Dean must have easy access to; he can then attach them to the platform and measure the vibrations (accounting for any dampening effects of attachment etc.). I'm hoping Dean will look into this.

Edited June 11, 2016 by TomBAvoider

[Todd S]

I see where http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3688642/   indicates for Results:

 

"For a given frequency, transmissibility was independent of intensity when below 1g. Transmissibility declined non-linearly with increasing frequency. Depending on the WBV device, vibration ranged from levels considered safe by ISO-2631 for up to eight hours each day (0.3gp-p @ 30Hz), to levels that were seven times higher than what is considered a safe threshold for even one minute of exposure each day (15.1g p-p @ 30Hz). Transmissibility to the cranium was markedly attenuated by the degree of flexion in the knees."

 

 

But when I look at http://tohatsu.org/skolarbeten/MMS/ISO%202631-1.pdf  I find in Annex B, section B.2:

 

“Increased duration (within the working day or daily over years) and increased vibration intensity mean increased vibration dose and are assumed to increase risk, while periods of rest can reduce risk.

 

There are not sufficient data to show a quantitative relationship between vibration exposure and risk of health effects. Hence, it is not possible to assess whole-body vibration in terms of the probability of risk at various exposure magnitudes and durations.”

 

 

I presume that the PMC3688642 statement about "levels that were seven times higher than what is considered a safe threshold for even one minute of exposure each day" comes from the following from the ISO 2631  B.3  Assessment of Vibration:

 

“A health guidance caution zone is indicated by dashed lines in figure B.1.

 

For exposures below the zone, health effects have not been clearly documented and/or objectively observed; in the zone, caution with respect to potential health risks is indicated and above the zone health risks are likely. This recommendation is mainly based on exposures in the range of 4 h to 8 h as indicated by the shading in figure B.1. Shorter durations should be treated with extreme caution.”

 

-----

 

I too would be interested in whether accelerometers are available at reasonable cost for self-measurement.

 

Todd

Edited June 11, 2016 by Todd S

[Dean Pomerleau]

Hi guys,

 

TomB wrote:

Per  PMID: 24081617 the vibration that might damage vision and hearing is transmitted to the head when you stand with your knees not bent. That's how Dean stands. 

 

Note my vibration plate wasn't actually on when I took that photo you're referencing with me standing on it. I decided to stand on it mostly for scale. But you're right, while I vary knee flexion quite a bit these days when I'm using it, I do sometimes stand rather upright as shown in the picture. As I'm sure you and everyone with the plate knows by now, the angle of the knees, back, neck, and posture in general, play a big role in how much vibration gets transmitted to different parts of the body. I haven't been nearly as adventuresome as either Sthira or Todd - limiting my experiments with the vibration plate to two-footed standing postures only.

 

But back to PMID 24081617. Having read the full text, the intro gives scant evidence for damage / injury as a result of Whole Body Vibration (WBV) Therapy. The evidence it points to seems to boil down to two case reports in the literature of vitreous hemorrhage (bleeding into the clear fluid of the eye) - PMIDs 19107038 from 2008 and 25389881 from 2011. These case reports suggest the injuries could have potentially been caused by WBV therapy, without giving any details about the patient's usage of the vibration therapy (how often, what type, etc.). This despite the fact that vibration therapy is a pretty commonly prescription for the morbidly obese, who can't or won't engage in other more aerobic exercise and who are particularly prone to retinopathy and vitreous hemorrhages. For example, this meta-analysis of WBV therapy for the treatment of type 2 diabetes [1] in obese individuals (prone to eye disorders) doesn't even mention anything about risks or any complications reported by the studies it analyzed.

 

Given how many IRB approvals have to have been given for the many studies of WBV therapy in the literature, in many cases involving the elderly and obese, you'd think they'd have flagged it by now and prevented such studies from happening if there really were serious risks involved. Further, given how many vibration machines are out there (10s or 100s of thousands, at least) in exercise studios, gyms and private homes, two case reports of potential eye bleeding seems like a pretty low incident rate. I'm much more concerned about falling off the darn thing and injuring myself when I close my eyes while on it to improve my balance!

 

In short, if there was an epidemic of eye bleeding or other dire consequences of using the many different models of these machines, it seems we would have heard of it by now, and there would be more substantive evidence. In fact, a PMID search for "vibration therapy injury" is flooded with the benefits of using WBV to treat injuries, to the degree it makes it very difficult to find any studies (if they exist) reporting WBV therapy causing injury. The one article [2] that I could find that supposedly dealt with both risks and benefits of WBV, talks almost exclusively about benefits, and pays very little attention to risks. It's "evidence" for risks, like virtually all the articles I've read that mention potential risks of WBV, seem to be based on extrapolation from repetitive stress injuries and lower back pain experienced by jackhammer operators, forklift drivers and/or commercial truck drivers, whose lifestyles and vibration exposure are obviously quite different from our own.

 

Further, if you're really worried about eye bleeding and you're willing to consider isolated case reports like the two again WBV, it's better to worry about mountain climbing in particular (here too), paintball, and scuba diving. Oh yeah especially stay away from soccer/football (here too), even golf (here too), and basketball (also here). Speaking of basketball never, ever blow up a basketball to the point it explodes - exploding basketballs can really mess up you eyes. Oh yeah, it goes without saying you can forget fishing too (something I advocate forgetting about anyway for humanitarian reasons☺). It looks to me like pretty much any enjoyable active sport or pastime involves some risk of eye injury, including vitreous hemorrhaging.

 

But having said all that, I agree with Tom that both caution (i.e. the precautionary principle) and more data are good things. We'd rather not expose ourselves deliberately to potential harmful levels of vibration, at least not for very long and not unless the benefits appear to outweigh the risks, however tenuous, poorly documented and rarely manifested they might be.

 

So just how much vibration are we actually getting from this thing? To that end, Tom says:

 

Fortunately, I believe Dean has the capability to solve the problem wrt. our particular model (though that will still not help the problem of possible individual machine variation) - Dean has been deeply involved in the engineering of self-drive cars, and research into self-drive cars involved extensive use of accelerometers, which I therefore surmise Dean must have easy access to; he can then attach them to the platform and measure the vibrations (accounting for any dampening effects of attachment etc.). I'm hoping Dean will look into this.

 

Who do you think I am, Bill Nye the science guy? ☺ [side note: Bill Nye looks pretty CRed. I wonder if he knows about it. He doesn't appear to mention it in his nutrition episode.]

 

FYI, I've been out of the smart car biz since 2008. In fact I haven't played with an accelerometer since this crazy project shortly after I left the work-a-day world, which wasn't half as crazy as this one. ☺

 

But your challenge/prodding apparently got my non-conscious mind working overnight. I woke up in the middle of the night (which for me is about midnight), with an idea in my head, only to see that Todd had beat me to it, in the post immediately prior to this one where he (formerly?) mentioned his suspicion that his iPhone has an accelerometer, a comment he (inexplicably) seems to have edited out of that post. Great minds think alike...

 

Yes, Todd is (was) right - smartphones have quite sophisticated Inertial Measurement Units (IMUs) built into them these days. They aren't military or research grade, but they are pretty darn good. Here are the specs on the IMU sensor in my Samsung Galaxy S5 Android phone, the Invensense MPU6500.

 

And yes, it probably won't surprise anyone to learn that there are a ton of (free) apps in the Google Play store that will record data from your phone's IMU. Probably true of Apple's App Store as well.

 

So yeah - I'll bite, and take on the challenge of quantifying the vibration from our machine. But I'm going to blame Kenton if it turns out to be killing us ☺. 

 

Stay tuned for my next post for the results of my experiments. Feel free in the meantime to post suggestions on what/how you'd like me to test it - short of doing a handstand or split on it. I couldn't do either of those even if you asked...

 

--Dean

 

---------

[1] Braz J Phys Ther. 2016 Feb;20(1):4-14. doi: 10.1590/bjpt-rbf.2014.0133. Epub 2015

Nov 17.

 

The effects of whole body vibration in patients with type 2 diabetes: a

systematic review and meta-analysis of randomized controlled trials.

 

Robinson CC(1), Barreto RP(1), Sbruzzi G(2), Plentz RD(1).

 

Author information: 

(1)Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS,

Brazil. (2)Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.

 

BACKGROUND: Whole body vibration (WBV) has been used to increase physical

activity levels in patients with type 2 diabetes mellitus (T2DM).

OBJECTIVE: To carry out a systematic review of the effects of WBV on the glycemic

control, cardiovascular risk factors, and physical and functional capacity of

patients with T2DM.

METHOD: MEDLINE, LILACS, PEDro, and Cochrane Central Register of Controlled

Trials were searched up to June 1st, 2015. Randomized controlled trials

investigating the effects of WBV, compared to control or other intervention, on

blood glucose levels, blood and physical cardiovascular risk factors, and

physical and functional capacity in adult individuals with T2DM. Two independent 

reviewers extracted the data regarding authors, year of publication, number of

participants, gender, age, WBV parameters and description of intervention, type

of comparison, and mean and standard deviation of pre and post assessments.

RESULTS: Out of 585 potentially eligible articles, two studies (reported in four 

manuscripts) were considered eligible. WBV interventions provided a significant

reduction of 25.7 ml/dl (95% CI:-45.3 to -6.1; I2: 19%) in 12 hours fasting blood

glucose compared with no intervention. Improvements in glycated hemoglobin,

cardiovascular risk factors, and physical and functional capacity were found only

at 12 weeks after WBV intervention in comparison with no intervention.

CONCLUSION: WBV combined with exercise seems to improve glycemic control slightly

in patients with T2DM in an exposure-dependent way. Large and well-designed

trials are still needed to establish the efficacy and understand whether the

effects were attributed to vibration, exercise, or a combination of both.

 

PMCID: PMC4835161

PMID: 26578253 

 

--------

[2] Age Ageing. 2009 May;38(3):254-5. doi: 10.1093/ageing/afp036. Epub 2009 Mar 16.

 

Risks and benefits of whole body vibration training in older people.

 

Brooke-Wavell K, Mansfield NJ.

 

Free full text: http://ageing.oxfordjournals.org/content/38/3/254.full

 

PMID: 19289489

[Todd S]

Dean,

 

Thanks for mentioning my iPhone accelerometer comment, which I subsequently edited out because I had done zero research on it -- the hardware or the apps.

 

My thinking was that I could strap my iPhone 6plus to my head to get measurements while in a handstand on the vibration plate. I'll take a look in Apple's App Store.

 

Todd

Edited June 11, 2016 by Todd S

[TomBAvoider]

Thank you Dean and Todd. Todd, re: ISO-2631, there must be additional supplementary materials on which these recommendations are based as they reference them explicitly in the guidelines, and maybe the PMC3688642 people had access to those (otherwise how could they specify those exact numbers while referring to ISO-2631?). The frustrating part is that while ISO-2631 makes references to "studies" and "reports" they don't provide the actual cites that I can see, so I find it very difficult to assess. I suppose one could chase down how this was all done, but my yak-shaving is extensive as it is and this is a whole new barn full of yaks.

 

Re: iPhone. I would not strap it to the head. All that would show is vibrations transmitted to the head, which are of limited interest, given that we already have PMID 24081617 telling us how to attenuate any possible damage by posture. Meanwhile, given the variability of individual people's body composition and posture, any accelerometer attached to the head would tell us how much vibration that head at that particular moment gets. What we want to know instead is how much vibration the machine is outputting directly, and take that as value 100%, which can then be attenuated variously. In other words, we need to measure the machine directly.

 

Anyhow, despite Dean seeing little value in my efforts, I will post some additional references and papers bearing more directly on developing protocols, and I have a feeling this time Dean will find them more useful in his own practice.

[Dean Pomerleau]

OK - so my results aren't in this post. I have a question for you physics nerds. Ignoring for a moment how to combine the acceleration generated by each of the three axes (which I'll combined using a vector sum), and focus on a single access of acceleration - say up/down. For simplicity, if the maximum acceleration in the up direction is 9.8 m/sec² (i.e. 1G),  and the maximum acceleration in the down direction is also 9.8 m/sec², is the relevant G-force 1G or 2G in this case? I'm thinking that going from -9.8m/sec² to +9.8m/sec² equates to a 2G acceleration, but I want to be sure I report things accurately and in accord with the accepted convention. Tom or Todd, I can't make heads or tails of the measurement protocol in ISO 2631. I've never been real strong in math/physics. Thanks.

 

FYI - Here's what I'm measuring. First I'm measuring acceleration at the plate at different speeds (frequencies) on both soft and strong settings, by putting my phone facedown on the plate and standing on top of it. Don't worry, it's in a case ☺.

 

Then I'm measuring acceleration at my head while standing using various machine settings and knee angles, using my phone as a bite plate. Fortunately teeth don't activate the touchscreen ☺.

 

Do these tests seem reasonable?

 

--Dean