Acupuncture and Acoustic Waves

Here is yet another study claiming to show “how acupuncture works” when in fact it does nothing of the kind. It does, however, reveal the bias of the researchers – it is, in fact, surprising that it was published in a peer-reviewed journal. Unfortunately, the mainstream media is dutifully reporting the biased claims of the researchers without any independent verification or analysis.

There are numerous fatal problems with this study. The first, like in many physiological studies that purport to be about acupuncture, is that the connection to acupuncture is tenuous. The researchers claim that they are testing the effects of an acupuncture needle – but what makes a needle an acupuncture needle? Other such studies were ultimately just seeing the effects of local tissue trauma. The fact that this trauma was induced by an “acupuncture needle” is not necessarily relevant.

This study is far worse, because it is simply using the acupuncture needle as a mechanism for inducing an unrelated physiological stimulus. This is similar to “electroacupuncture” where electrical current is applied through an acupuncture needle – what you are actually studying is the effects of electricity, not “acupuncture.” Applying electrical stimulation, or some other physiological stimulus, is the equivalent of injecting morphine through a thin needle and then claiming this demonstrates how “acupuncture works.”

This is the most significant fatal flaw of this study. What the researchers did was use an”acupuncture needle” (i.e. a needle) to apply a mechanical vibration (through a piezoelectrical device – one that converts electricity to mechanical force, or vice versa) to the tissue. They justify this procedure by likening the vibration to manual manipulation that acupuncturists will do to the needle after insertion.

However – they were vibrating the needle at up to 50 hz – 50 times per second. There own data shows that low frequencies have no physiological effect. Essentially the researchers were measuring acoustic shear waves (ASW) in the tissue in response to this vibration. This is less than shocking – vibrational waves in tissue in response to vibration. But they also measured the release of calcium by the cells. They argue that the ASW cause the local cells to release calcium which then in turn triggers the release of endorphins – and that’s how acupuncture works.

What they actually showed, if anything, is that acupuncture does not work through this mechanism. They proved the opposite of what they claim, because their own data shows that the calcium release is present at 40hz, it is barely present at 20hz, and completely absent at 10hz and 5hz. So, to be generous, unless the acupuncturist is continuously vibrating the needle at 20 times per second, the physiological mechanism they are seeing is not relevant. It’s impossible, using just your hands, to vibrate a needle at 20hz. Further – acupuncturists don’t vibrate the needle, they may twist them or move them up and down, but not at anything approaching 20hz. The authors themselves state:

In studying acupuncture, an important and frequently overlooked procedure is the manual needle manipulation performed by acupuncturists after needle insertion. The needle manipulations are typically a series of rapid bidirectional rotation or up-and-down piston movements.

The authors failed in the most basic sense to demonstrate that their physiological model is at all relevant to acupuncture; they failed to note the relevance of the frequency of the vibrations they were using or the plausibility that this relates to the “rapid” movements of the needle that acupuncturists sometimes make.

It should be further noted that in clinical studies the movement of the needle by the acupuncturist, when controlled for, does not contribute to a measured clinical effect. The effect of the needle movement is the major premise of this research, and yet it does not appear to be true.

The study also looked at the acoustic waves themselves and claim that they were more pronounced when the needle was inserted at an acupuncture point than when at a non-acupoint. I find this result frankly unbelievable. A review of the research does not support the notion that acupuncture points or meridians exist. Further, the clinical research shows that there is no difference in effect between needling acupuncture points or non-points (sham vs “true” acupuncture). About this the authors write:

Along with it is a system of tracks called meridians by the practitioners but invisible anatomically.

By “invisible anatomically” they mean – there is no evidence they exist. Meridians are the floating, invisible heatless dragons of Carl Sagan.

The fact that these researchers found results that depend on the existence of acupuncture points seriously calls into question their methods. Their results should be viewed as the equivalent of N-rays or Bem’s future cognition results – likely artifacts of sloppy research and researcher bias.

It should also be noted that this study did not even look at clinical effects from acupuncture, so they were unable to correlate any of the physiological parameters they were looking at with any putative effect. Therefore there are good reasons for thinking the effects they are seeing are not relevant to acupuncture, and the researchers provide no evidence that they are.

The flaws outlined above are enough to render this study useless as support for acupuncture, but I think it’s also worthwhile to consider the bias of the researchers. I usually don’t spend time doing this, but there are a few points worth making with respect to this study. This study comes out of Hong Kong. There is a Columbia University author, but he is a non-MD electrical engineer who provided only technical assistance, and is not a medical researcher. This is relevant because a prior review of acupuncture research published in 1998 showed that 100% of the acupuncture studies coming out of Hong Kong (and several Asian countries) were positive. This is in stark contrast to acupuncture studies from the West or overall.

The most reasonable conclusion to draw from this is that there is extreme researcher and/or publication bias in these countries. Proponents might argue that Asian researchers know how to do acupuncture properly, but that explanation is not credible, and doesn’t apply to physiological studies like the current one.

I also note that one of the lead authors, Siu Kam Lam, was convicted of stealing 3.8 million dollars in donations while in public office and served jail time for this crime. Facts like this are always difficult to deal with. Withholding this information from this article seems like an omission, as this might be relevant in putting the honesty of the researchers into context. But it can also be interpreted as poisoning the well. In any case – I see it as full disclosure, and the reader can make of it what they will.

I will also note that the authors, in their introduction, give a glowing review of acupuncture, and shamelessly cherry pick the evidence to make it seem as if there is good published support for acupuncture. The opposite is true – systematic reviews show that there is no specific effect from acupuncture. It is nothing more than a ritualized placebo.


There is no evidence for any of the underlying claims of acupuncture – not even the existence of acupuncture points. The clinical research shows that acupuncture does not work – in other words, that it does not matter where or even if you stick the needles. Acupuncture is a placebo treatment.

Acupuncture proponents, however, continue to study the non-specific local physiological effects of sticking needles into tissue, and often even producing a physiological stimulus through the needle that has nothing to do with how acupuncture is practiced. They then claim that “finally” they have discovered how acupuncture works – begging the question of if acupuncture works.

This current study is no exception. But interestingly, this study may be the first that actually proved that they found a mechanism by which acupuncture cannot work. The effect they found was only present when the needle was vibrated at 20hz or more – something which is not done and seems impossible for the acupuncturist to achieve.

Posted in: Acupuncture

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7 thoughts on “Acupuncture and Acoustic Waves

  1. windriven says:

    “This is relevant because a prior review of acupuncture research published in 1998 showed that 100% of the acupuncture studies coming out of Hong Kong (and several Asian countries) were positive. This is in stark contrast to acupuncture studies from the West or overall.”

    Dr. Novella, you missed the obvious conclusion: Asians have meridians while Caucasians don’t. Whether this is genetic or the result of some quantum geophysical phenomenon focused in Asia is open to question, though I have it on good authority that this is being investigated by a crack team at the University of Macau School of TCM. Results are to be reported in The Onion soon.

  2. daedalus2u says:

    I commented on this over at Neurologica, but looking at it more carefully, it is even worse than I thought. I think I see data manipulation.

    It sure looks like figure 1 was chosen to maximize the apparent effects of the excitation at the acupoint and to minimize it at the non-acupoint. The MRI slice is centered on the acupoint and is the depth to maximize the magnitude of the displacement. The same slice is used for the non-acupoint which is off center. It would be expected that the magnitude of the displacement would be less when it is looked at off center.

    You can even see that the displacement is asymmetric in figure 1.d.5 where it is symmetric in 1.d.2. This is clear evidence that the displacement measurement is not equivalent for the two tests.

    My understanding is that with MRI, one can choose what ever slice one wants to use. If so, then they deliberately chose the two slices to be “the same”, and centered around the point they treated as the acupoint which would maximize the displacement measured at the acupoint and reduce the displacement from the non-acupoint. To me, this is disingenuous.

    The “measurement” they make of tissue stiffness are really muscle stiffness, which can change by 2 orders of magnitude depending on muscle tension (which they didn’t measure, mention or correct for). Muscle really is pretty isotropic.

    The reference they cite does not support the differences they measured in the calf muscle via their technique.;2-1/abstract

    This study finds that muscle is pretty isotropic, that is different parts of the same muscle have about the same stiffness. It pretty much has to work that way because stiffness is displacement under load. For all the muscle fibers in a muscle to work together, they have to all have pretty much the same displacement under load.

    The “reason” they measure anisotropic stiffness properties at acupoints and non-acupoints is because they are doing the measurements wrong. They are doing the measurement of displacement centered at the acupoint even when the excitation is not centered at the acupoint, but then treating it as if it was. This is clearly wrong and cannot give accurate results. It would show up as reduced amplitude, exactly what they measured.

    This is a highly flawed paper which (because of its flaws) sheds no light on acupuncture.

  3. tommyhj says:

    sad thing… We can bark all we want about this being extremely bad “research” but it will remain in public space, and for all non-science people (read: all who wants to make money from acupuncture or are philosophically inclined to refuse real science) this paper sounds so complex that “it must be true”. Same thing with homeopaths and the “quantum memory of water”. The asian countries have generated such a large amount of studies that are just plain wrong, but people who for various reasons “want to believe” will take them to heart anyway. Repeat a lie enough times and the amount of believers will eventually reach critical mass for the lie to become true. And I’m not sure we can fight the entire asian population og true believers… I can’t even tell my co-workers that acupuncture is a scam for fear of being chastised :)

  4. phmag2001 says:

    As a researcher who has specialised in magnetic resonance elastography (MRE) I was absolutely astounded when this paper popped up on my radar. I almost feel like it may give the field a bad name now. Such a poor research paper, full of holes that should have been flatly rejected by the journal.
    Michael Green

  5. Sabio Lantz says:

    Excellent review — the politics and economic are critical in understanding why people are investing in sacrificing rationality or deceiving others.

    As a former acupuncturist, I watch with amazement at how we clung to any shred of theory supporting our profession and gleefully sacrificing our minds.

    BTW, besides “up and down” or “twisting”, I did occasionally vibrate — but you are right, it is not classically taught as I recall. But nowhere near that frequency. But it sure felt like I was doing more — both to me and to my patients. Even if it wasn’t. :-)

    (Still no way to follow these comments? — Please !!) I am sure your WordPress template has a box to check that says “Allow to follow comments by e-mail notification”.

  6. ladentduchat says:

    Hello. I’m seem to have done a newbie mistake using cut-n-paste about a fortnight ago when I tried to comment on this (my first try seem to hover in moderation). So, here is another try.

    A funny thing about the article (doi: 10.1007/s00424-011-0993-7) in question is the very short time from submission to acceptance. It was received June 7 and accepted June 28, 3 weeks! When I did a quick check on the other articles in the same issue of the journal the average time from submission to acceptance was about 3-4 months. Moreover, a few of the authors carried out a review (doi: 10.1007/s00424-011-1017-3) by invitation of the same journal. This time the review process only took a fortnight (Aug 2 – Aug 16). Nice title also, “Ancient Chinese medicine and mechanistic evidence of acupuncture physiology”.

    Can’t someone with a PhD in medicine (maybe with some help from a physicist) write a rebuttal?


  7. ladentduchat says:

    Hello. 3rd try…how to avoid moderation…hmm…it may look funny if the 2 previous attempts suddenly pass moderation…whatever…

    A notable thing about the article discussed above is the very short time from submission to acceptance. It was received June 7 and accepted June 28, 3 weeks! When I did a quick check on the other articles in the same issue of the journal the average time from submission to acceptance was about 3-4 months. Moreover, a few of the authors carried out a review, “Ancient Chinese medicine and mechanistic evidence of acupuncture physiology”, by invitation of the same journal. This time the review process only took a fortnight (Aug 2 – Aug 16).

    Can’t someone with a PhD in medicine (maybe with some help from a physicist) write a rebuttal?


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