People routinely experience muscle pain and acutely sensitive spots in muscle tissue — “muscle knots.” They can be surprisingly severe, and massaging them often seems to help quite a bit. What’s going on? The dominant theory is that a trigger point is a patch of tightly contracted muscle, an isolated spasm affecting just a small patch of muscle tissue. Unfortunately, after a few decades it’s still just a theory, and trigger point science is a bit half-baked and somewhat controversial. It’s not even clear that there is really a problem in the meat at all; it could be a sensory “disturbance,” for instance. Meanwhile, people keep hurting, and there is little doubt that there is an important, almost epidemic phenomenon here in need of explaining and treating. Massage — especially self-massage — remains a safe, cheap way of trying to deal with it, and there is some evidence that it can provide some meaningful relief (e.g. Furlan et al) is probably the best example). That’s why I have a large tutorial devoted to how to self-treat “trigger points” — whatever they really are. But it’s very important to keep in mind that they are not well understood.
I don’t want to believe. I want to know.
Why do I feel the need to challenge the clinical concept of trigger points? Because the science of trigger points is weak and has yet to produce a proven, reliable way to treat pain. Because many serious, earnest experts have declared their annoyance with dogma and wild speculation about trigger points. Because it’s all a bit half-baked … after decades in the oven.
And yet my ebook about trigger points and myofascial pain syndrome is my best-selling product. It is my meal ticket: it literally pays my rent, buys my food, and keeps the lights on. This website would not be 10% of the resource that it is without those sales. I wrote it because, during my 10-year stint as massage therapist — 2000–2010, R.I.P. — I got more therapeutic mileage out of the idea of trigger points than any other clinical concept. Or so it seemed. In my experience, I was able to help more people in that way than any other, by far — good bang for treatment buck.
And there’s the problem: I don’t trust “my experience” farther than I can throw it, and I take it as an article of faith that I misunderstood the meaning of many of my clinical experiences. I was never an over-confident therapist. I was prone to earnest self-deprecation and making a virtue of candid confessions of my limitations. And yet I wrote an entire book based more or less on my experience. Experiences like the one I’ll describe in the next section.
The three most dangerous words in medicine: in my experience.
Mark Crislip, MD
A few years ago, during a family visit, my wife’s uncle was suffering from a sickening ache on the front of his shoulder, like a toothache in his anterior deltoid. He was a weathered, cheerful former farmer who’d lived hard and wasn’t the sort to complain or ask for help, especially from his nephew-in-law the massage therapist — a profession that probably seemed a bit strange to him. However, he was pale with pain, and I’d never seen him so subdued, so he accepted my assistance without much fuss. A quick clinical quiz determined that the problem had been worsening steadily over a few weeks, and had driven him to the doctor where it had been chalked up to arthritis. And yet the pain was off the charts in a joint that is rarely afflicted by arthritis, and had been worsening much too quickly for that diagnosis. If this was arthritis, it was certainly an odd example of the breed! He’d also been told it might be bursitis, a common misdiagnosis that was an even worse fit.
I recognized the signs of what I knew as an active muscle knot or “trigger point.” I recognized the signs of what I knew as an active muscle knot or “trigger point.” (And, honestly, I would probably still call it that today — for lack of a better term. This naming problem will come up again.) I recognized the location as being strongly characteristic of a typical pattern of referred pain from the infraspinatus muscle, and one of the more dramatic examples of that odd phenomenon: poke the shoulder blade in back, but feel it in the deltoid muscle on the front of the shoulder. I prodded the infraspinatus just so, and sure enough he responded with surprise: “Yeah, hey, wow, that’s it! I can really feel that in the front of my shoulder.” I rubbed the spot with a practiced thumb for all of five minutes, and …
He was cured. Immediate, total, permanent pain relief. I fixed him in less time than it takes me to make coffee.
My uncle-in-law spent the rest of that weekend swinging his arm around, chuckling, and saying things like “Who knew?” and “Well, damn, ain’t that something!” He brought it up every time we visited after that. He mentioned it the last time I saw him, just recently, near death — it was his defining memory of me.
That is the most dramatic treatment anecdote of my career. It was not an unusual sort of clinical experience — I had many similar ones — but it was the high water mark, the best of the best, the most unqualified victory I ever had over pain. The “magic hands” myth was at full power, because the spot I chose to treat was so oddly remote from the pain, so counterintuitive. Nothing is better for a massage therapist’s reputation! It seemed like a miracle to him not only that I cured him, but that I did it by pushing a spot on “wrong” side of his shoulder.
Experiences like that were good enough for me when I was a massage therapist … but I’m not a massage therapist any more. My career has taken a strange turn from massage therapy to science journalism, and it has exposed me to countless worrisome examples of seriously flawed clinical reasoning … most of them shored up with anecdotes like that.
Experience is not enough. Things are not always what they seem, and the mind is afflicted with many common reasoning errors and illusions. Throughout history, people have believed goofy things based on “experience.”1 It has become my job to study and understand those mistakes. Many of my own beliefs, one by one, have fallen like timber, hacked down by new critical thinking skills. I no longer believe 90% of what I did in my first couple years of selling therapy.
Empiricism is supposed to urge that people be distrustful of authority and go out to look directly at the world. But of course this is a fantasy. It is a fantasy in the case of everyday knowledge, and it is an even greater fantasy in the case of science. Almost every move that a scientist makes depends on elaborate networks of cooperation and trust. If each individual insisted on testing everything himself, science would never advance beyond the most rudimentary ideas.
Peter Godfrey-Smith, Theory and Reality: An Introduction to the Philosophy of Science
The low-hanging empirical fruit is gone from medicine. The handily tested theories are all gone. All the challenges left in health care are the slow-motion and multifactorial, the microscopic, subtle and psychological — messy etiologies. No one will ever discover the one true cause of chronic pain the way Dr. John Snow proved with a simple test that cholera was coming from a polluted well: he removed the pump handle, and the cholera stopped. The handily tested theories are all gone. All the challenges left in health care are the slow-motion and multifactorial, the microscopic, subtle and psychological — messy etiologies.Simple, no? Goodness, no, not even that: to prove that cholera wasn’t in the water, some smartass biologist drank a glass of the stuff … and got away with it, because he just happened to be immune, an unlikely coincidence. So he was convinced of an utterly wrong answer by experience — and he convinced a lot of other people at the time.
Today we face vastly more complicated medical puzzles, and yet deeply flawed and biased personal experience is still constantly used as the main justification for treatment methods.
For years, the introduction to my book clearly stated that “trigger points are good, hard science.” Hmm. Not quite. There is quite a lot of science, and some of it is interesting and good science — generally better than fascia science, I believe2 — but as a whole it certainly doesn’t add up to much. There are too many serious problems. (I changed the phrasing of the introduction early in 2012.)
Here’s a good example of a particularly scathing expert opinion: Dr. Fred Wolfe, a rheumatologist, calls trigger point science a kind of pseudoscience, “cargo cult science” and “pseudo-pseudoevidence based medicine,” in which the so-called evidence “never reaches the level of evidence, and assertions, ‘facts,’ definitions, and beliefs are derived without testing or without adequate scientific basis.”3 That double-pseudo is quite the slap: he’s saying that trigger point science is even worse than (single pseudo!) pseudoevidence-based medicine, or medicine based on rather low quality evidence.4 This is from an articulate expert, one who worked with Travell & Simons directly, and yet he is quite exasperated with the so-called science of trigger points, and by no means is he the only one.
The more I read the more I doubted. The book [the Travell & Simons “Bible”] represented opinion, not science. None of the trigger points or their treatments were validated; none were tested for reliability. There were almost no studies … just testaments. Most of the perpetuating factors were plain wrong, and represented outdated, overthrown junk science.
Dr. Fred Wolfe, rheumatologist, describing his reaction to the “bible” of trigger points
The perpetuating factors were the first things that bugged me about those books, too.
I feel the need to challenge trigger points as a concept because I don’t trust my own experience any more, and because the science of this kind of pain is more limited and less illuminating than I once thought. Although there’s definitely a phenomenon in need of explaining — there are sensitive spots, people do hurt, the pain is real — much less can be said with confidence about the nature of that phenomenon than I would like. So I am planning a series of updates to the book with the general goal of presenting the notion of a “trigger point” as a weak metaphor — much like the more obviously quaint “muscle knot” — more than an actual known thing that resides in meat. It will become a book more about muscle pain than trigger points. Fortunately for me, muscle pain — the sensations of stiffness, aching, or even agony in muscle — is a worthy topic, whatever the etiology, however it works. So I still have a book, and it is still worthwhile.5
I will also condemn cultish and dogmatic promotion of trigger point therapy as a panacea — which is much too common — and leave my readers with no doubt that many common practices under the banner of myofascial pain syndrome are nonsense or dangerously close to it. I am already critical of some of the worst offenders, but I will get harder still. I will get hate mail and hateful comments on Facebook … and much of it will cite “experiences” like my own. Won’t that be ironic?
Many of my customers, friends, colleagues, and mentors are watching this process with considerable interest. It’s not every day that someone seriously questions the validity of his own meal ticket! I have a few ground rules for this process, things I only want to have to say once:
Plus one more point that is a little too much for a bullet point …
The main reason and underlying assumption for my trigger points doubts is mainly that they may not be what they seem to be. Clearly they seem to be “muscle pain,” but it’s not at all clear that there is anything wrong with the muscle itself. Muscle pain effectively communicates a subjective experience — one that I constantly endure — but that doesn’t mean the muscle is where the trouble is.
Pain is an experience generated by the brain, based on pre-conscious processing of many signals (not just dumbly reporting whatever nerve endings detect in the tissue).7 So what seems to be muscle pain could be more akin to phantom limb pain, a ghostly projection, and not an “issue in the tissue.” This possibility has the potential to explain quite a bit about the phenomenon of so-called trigger points. Even if there is a tissue issue, it might not be all that important — just the tip of an etiologic iceberg.
It is not clear that the phenomenon of trigger points — sensitive spots — are actually associated with any readily diagnosable physical, clinical sign like tissue hardness. But supposedly they are! Supposedly every trigger point is a painful, tight patch of muscle tissue — a palpable lump or muscle “knot.” This is taken for granted by most of the world’s massage therapists. But are muscles actually tight or hard where they hurt? Believe it or not, it’s not clear, and this is one of the main ways that the science of trigger points is pretty half-baked. It could have and should have been clearly answered a long time ago … but it really hasn’t been.
In a nice little 2010 experiment in the Journal of Pain,8 the hardness of the trapezius muscle was tested and compared with sensitive points, before and after intense exercise. The most sensitive spots were not just soft, but the softest spots — the opposite of what most people would expect, and the opposite of what we “know” from trigger point lore. In a dozen healthy patients, the two “typical locations for tender points” were not just soft, but the softest spots in the muscle — the opposite of what most people would expect, and the opposite of what we “know” from trigger point lore. In general, “a heterogeneous distribution of pressure pain sensitivity and muscle hardness was found.” Translation: the conventional wisdom that you’ll find the most pain at “tight” spots in muscles is probably a misleading oversimplification, at best.
Oh, dear. That’s not how a description of trigger points should sound! This is a bit of a problem. It’s not a large experiment, but it didn’t particularly need to be to make this point. Even a small test should have clearly showed that the sorest spots are the hardest — if they really are. The muscle was particularly well-chosen: the trapezius is possibly the most massaged of all muscles, and assumed to be one of the “knottiest” in the human body. If sore spots don’t correlate well with texture in the trapezius, they probably won’t anywhere else either.
In the study just discussed, sensitivity was measured with a therapist’s “magic hands,” and more objectively with a tool: a pressure algometer. Guess what? Thirty percent of the sensitive spots identified by hand were not identified by the more accurate algometer. Not exactly fabulous. Magic hands? Magic algometer, more like.
Diagnostic accuracy is a problem for trigger points. If different professionals cannot reasonably consistently find the same trigger points in the same patients, then trigger point therapy has a practical problem at the least, or a rather dire existential problem at the worst. Either it means that trigger points are quite difficult to detect (that’s the practical problem) … or that they aren’t actually there in the first place (and that would be the existential problem).
This sort of thing is mainly determined using inter-rater reliability tests, which are quite persuasive: when two therapists tested separately point to different spots and say, “There’s your problem, right there,” people can easily see that someone must be wrong. It is difficult indeed to treat what you cannot find. (Although not as impossible as it might seem at first — stay tuned.)
Probably the first reliability study of trigger points was in 1992.9 Dr. Fred Wolfe’s description is more dramatic than an episode of Downton Abbey:
In 1992, we performed a study of trigger points. A group of four myofascial pain experts, selected by Simons and including Simons, blindly examined four patients with MFP. The examiners were allowed to take as much time as they needed; they could examine but not interview the patients. As we had mixed MFP patients with those who had fibromyalgia, it was a blinded experiment. These MFP experts were no ordinary examiners. They were the best. They wrote the book, they did the lectures. But, in the end, they could not find or agree on the trigger points. It was a disaster. The examiners were distraught. After the results were in, they protested and wanted to change the protocol and purposes of the study (post hoc). It wasn’t fair, they said. Glenn McCain, one of the rheumatologists, exploded in outrage. It was intolerable, he said, to alter study results. He was so angry that the opposition stopped. Subsequent delays and disagreements over the methods, results and discussion continued and almost prevented publication. But time took over; people forgot, and the study—a little toned down—came out in the Journal of Rheumatology. If we believed in trigger points and The Trigger Point Manual before, we were a lot less secure in our beliefs now.
For all that, the final wording of the paper does not seem quite like a “disaster,” and of course there is probably another side to the story. You can easily see signs of the tense negotiation over the wording in the abstract. On the one hand, there were “problems with reliability.” On the other hand, with a “more liberal definition of trigger point,” they were indeed found. “Our data are exploratory and tentative” and they “suggest that attention to definition and reliability [no shit] are required to advance our knowledge.”
The data were indeed not enough to settle the question, and 20 years later the reliability evidence remains about the same: inconclusive but discouraging. A 2009 study by Lucas et al surveyed the state of the art: what science has been done so far? It’s a confusing mess, unfortunately!10 Past research has not “reported the reliability of trigger point diagnosis according to the currently proposed criteria” (exactly echoing Myburgh et al from the year before11). The authors also explain that “there is no accepted reference standard for the diagnosis of trigger points, and data on the reliability of physical examination for trigger points are conflicting.” In other words, some studies were somewhat positive, and some were somewhat negative, and after all this time apparently no one quite agrees what we’re looking for (a problem in itself).
On the bright side, perhaps it means that this isn’t over, and there might still be hope for the reliability of trigger point diagnosis. On the other hand, it’s quite discouraging that the evidence is so conflicted and definitions and standards remain so unsettled after so long. If trigger point science was solid and diagnosis reasonably reliable, the data would not be conflicting. And the conclusion of the Lucas paper certainly seems disappointing and completely at odds with what professionals are out there doing every day:
Physical examination cannot currently be recommended as a reliable test for the diagnosis of trigger points.
So, should we give up? Is it futile to grope about for trigger points in muscle? Let’s ask a radar operator first. From radar science, we learn that reliability isn’t everything.
Difficulty detecting something does not mean it isn’t there or that it isn’t worth trying. Lots of things worth looking for are hard to find, the process plagued with inaccuracy and false positives and negatives.
Like enemy fighters.
“Signal detection theory” started with radar in WW II. There was a painful trade-off that afflicted the technology: you could dial up the sensitivity of the radar to be sure of detecting every invading plane, but then you’d end up scrambling your pilots to defend against invading geese as well. Or you could dial it down to prevent those false alarms … but then you’d (disastrously) miss genuine enemies.
It’s a hell of a dilemma, and as unavoidable as gravity: it crops up everywhere that anyone tries to separate “signal” from “noise,” with any attempt to detect anything indirectly. It is the same as the trade-off between diagnostic sensitivity and specificity in medicine. Both are highly desirable, but you tend to get more of one only at the expense of the other. Just replace “enemy fighters on radar” with “tumours in MRI scans,” and you see how similar these problems are. Radar operators were “diagnosing” invading planes. Radiologists are detecting invading pathologies.
If trigger points are a detectable phenomenon, how hard might it be to detect them? All indirect detection challenges are tricky by nature. Consider this fascinating recent example, where researchers discovered that fMRI studies of brain activity frequently “find” signals “when there wasn’t really anything happening.” Uh oh! Brain activity signatures are real, but detecting them is … well, “difficult” doesn’t really do it justice.
The problem of detecting lumps in muscles is greatly complicated by pareidolia, a proven and common kind of illusion in which we perceive what we want or expect, rather than what is real. It literally happens to the best of us. Pareidolia occurs in any situation where humans are trying to interpret unclear signals, and it is always amplified by a clear bias. And financial interest. And it certainly applies to diagnosing anything by feel — “palpation.” It is certainly possible — maybe even likely — that I misinterpreted the biological meaning of what I felt. Day in. Day out. For years.For a much more detailed discussion of this, see Palpatory Pareidolia: Sensory illusions, wishful thinking, and palpation pretension in massage and other touchy health care. This section is just a quick summary of PP as it applies to the question of trigger point.
For many massage therapists, trigger points as a palpable entity are accepted dogmatically, and it is the basis for a lucrative career. If a diagnostician expects to feel trigger points, she probably will. If trigger points really are bumpy, palpatory pareidolia will cause a lot of overdiagnosis. It will be one of the main reasons that diagnosis is hard.
But what if trigger points are not actually palpable at all? Alas, palpatory pareidolia is all-too capable of disguising this fact. Therapists will probably feel them anyway, because they think they should. You may be skeptical, but it is actually almost routine for large numbers of perfectly intelligent human beings to suffer from pareidolia-powered misperception. Our brains really are that weird and fallible. (In fact, pareidolia is nothing.12) This has happened many times in history. If you accept pareidolia as a reality (and you really can’t avoid it), then you also have to assume that therapists will find what they are looking for, whether it is actually there or not. It means that diagnostic sensitivity will be off the charts at the expense of specificity, and so the rate of false positive trigger point “finds” will be off the charts.
I spent many years overconfidently “detecting” trigger points in tissue, and I am fully, humbly willing to admit that I was probably wrong about many of them, and it could be even worse than that. That does not mean I was wasting my time, or that my clients were not enjoying a perfectly meaningful and useful massage experience. But it is certainly possible — maybe even likely — that I misinterpreted the biological meaning of what I felt. Day in. Day out. For years.
The first principle is that you must not fool yourself & you are the easiest person to fool.
Some clinical phenomena are more difficult to assess and we expect diagnostic reliability to be poorer for them. Obviously one wants to be wary of using this as a lame excuse for poor reliability, but neither do we want to ignore the obvious: some diagnosis is just difficult. If trigger points actually cause lumps in muscle tissue, it probably is tricky to find them reliably. Lumps under thick skin are not exactly a palpatory slam dunk!
In attempting to diagnose trigger points by feel, there are many potential false negatives and positives. It may be quite a needle-in-haystack challenge to find a trigger point in muscle, with far more ways to either miss one or be fooled into thinking you’ve found one. This is also true of many medical conditions, which is precisely why palpation is never the sole diagnostic method.
|false negative||=||It’s there! But it’s hard to feel. It might be too small (microscopic or close?) or too subtle (maybe only 10% firmer than surrounding muscle). Maybe it’s too buried, or adjacent to disorienting anatomy (sometimes hard to tell healthy bumps from the unhealthy ones).|
|false positive||=||Mostly causes by normal bumpy stuff in anatomy — decoys! Powered by palpatory pareidolia. Could be pure illusion. Misinterpretation of variations in muscle tone that have nothing to do with trigger points.|
For contrast, poor diagnostic reliability for chiropractic subluxations would be considerably more damning, because there are a lot fewer possible subluxed joints in the spine than possible trigger points in muscle — fewer potential false negatives or positives! That means that chiropractors would look a bit ridiculous if they couldn’t agree on a diagnosis when choosing from only five lumbar joints. Pop quiz: can they?13
Context matters. Poor inter-rater reliability doesn’t mean much on its own, if you don’t know much about the phenomenon you’re trying to detect. But when the phenomenon you’re attempting to detect is debatable and hypothetical in the first place, lacks any corroborating objective evidence, and it all could be explained by pareidolia … then poor reliability becomes a serious basis for concern. Detecting cancers is tricky too, but it’s a lethal certainty that they are there to be found. One of the main reasons that I have “trigger point doubts” is that the detection challenge isn’t the only concern about trigger points.
We do not yet actually have smoking gun evidence of poor reliability: just weak but discouragingly conflicting evidence that cannot actually answer the question. It does not tell us whether trigger points are genuinely lumpy but hard to detect … or non-lumpy in the first place.
The cost of a diagnostic miss may be relatively trivial. It’s ruinous to diagnose a cancer where there is none, but not so much with trigger points.
Diagnostic precision may not be critical to the value of the therapy. Does it actually matter if you know exactly where a trigger point is? Massage can easily cast a wide “net” of pressure, touching most or many trigger points without precision.
With well-established official guidelines and proper training, accurate diagnosis might be a snap, and there is already evidence that skill could make a difference.14 The therapists of the future may pass reliability tests with flying colours. But there are no such guidelines, and most professionals probably do not even know what the proposed guidelines are! And so for now trigger point “diagnosis” is obviously a bit dodgy in practice. Which may or may not matter much. As long as you don’t mind your therapist pretending to know the unknowable.
There are a lot of questions I have no answer for. Is there a pathological entity? Is there a source of nociception? Is there something wrong with tissue that is ever, in any sense, to any degree, “fixed” by a mechanical intervention, a real effect on tissue? Where there is sensory smoke there must be tissue fire? I can’t answer any of that. I still tend to suspect that there is a pathological entity, because some experiences just seem awfully hard to explain without it. But I have become super cautious about saying it or believing it, considering that the search for that thing has been mostly a failure for decades now, and there isn’t even one theory that isn’t full of problems, festooned with pseudoscience, and failing to produce a reliable therapy. Maybe it’s just a damned difficult thing to identify (nature is full of things like that). Or maybe there is no “it,” and the pain really is all just a bunch of sensory smoke. Or maybe the truth is in the middle: there is an obscure physical process, but therapy has no “real effect” on it, just sensory tuning.
No matter what is or is not really going on in tissues, here is what I can say with a little more confidence:
“Trigger point therapy” consists of a combination of good story and vivid sensation. This is often helpful to patients regardless of what the story is, or the sensation, so long as they reinforce each other and there’s a net effect of reassurance.
Manual therapists (and acupuncturists) are storytellers and, particularly, sensation-makers. Both story and sensation are powerful ingredients. Both are present in nearly all therapeutic interactions. Therapy consists of telling a patient nearly any story about what is going on, and then providing any kind of strong or novel sensory experience to validate the story. “Wow, that’s such a strange, potent feeling that it must mean that the therapist has found something important and is fixing me! Yay!”The more consistent the sensation is with the story, the better (“Magic hands” impress people). It’s more than placebo15 and less than medicine.16 The narrative and sensory input give people’s brains what they need to “reconsider” the meaning of their symptoms.
How much the quantity and quality of each component matters is unclear and variable, but the combination is probably much more likely to work rather well at times than either one alone. And I’m guessing that sensation is probably the more active ingredient, the special sauce that makes manual therapy interesting and better than placebo. In a few modalities (those that produce less or gentler sensation), the story is probably the major active ingredient. But in many others (strong massage, needling), the sensations probably eclipse the narrative. Sensation alone can communicate a lot. It alone, or nearly alone, can tell the story. Even with no other cues, the patient may think: “Wow, that’s such a strange, potent feeling that it must mean that the therapist has found something important and is fixing me! Yay!” And lo, they actually feel the heck better. Because that’s how pain works. (Remember: pain is impressively modulated by Mr. Brain’s pre-conscious threat assessments.)
This model of therapy does not need to (and can’t) respond to or “fix” a specific pathological or dysfunctional entity in order to kinda, sorta work. There might be a source of nociception, or there might not. And it could work with virtually any relatively minor or non-ominous source of nociception — anything that can be safely poked, basically.17 The results of such a treatment are also going to be modest, variable and temporary, and yet occasionally rather impressive … which is just what we see in the wild, regardless of the specific story told, and regardless of the specific sensations induced. Most manual therapies produce roughly the same results, pretty much no matter what’s wrong.
By offering an explanation a little beefier than “just placebo” I am hoping to satisfy readers and myself, and I do think that induced sensory modulation is kind of a big deal and should not be underestimated. It may actually possess the “power” that mere placebo is often given too much credit for. Sensory modulation often is severely underestimated. It seems to me that a therapist who can artfully induce substantial sensory modulation, with artful sensory input, is probably doing something much more interesting than just talking a patient into feeling a bit better for a while.
If my best guess is right, then the stories and sensations that are the most pleasing and vivid and non-threatening should generally perform well... which is probably why massage generally seems to be one of the strongest contenders and actually has a bit of an edge in the research. It’s also why I don’t feel too badly that I’m still selling a book that tells a particular story and a safe, cheap method of producing sensations that reinforce the story.
The colorful history of medicine and quackery is overflowing with people who “swore by” treatments that were bizarre and perilous. Bloodletting was popular almost until the 20th century, despite being relentlessly harmful. Some of the most lethal “cures” in history were inspired by the discovery of radiation. People happily drank metals like mercury and silver. Even drinking urine had near fad status for a while! They tried to purge disease with sulfuric acid, and stimulate their vitality (and virility) with powerful electric shocks. Women were sold Lysol as a douche … and women actually went along with it for a while. Voluntary lobotomy may be the craziest of them all: it was a popular treatment for all kinds of psychiatric disorders, and at least fifty thousand people volunteered to have their brains lanced.
All of these terrible treatments, and many more obscure examples, had many fans and enthusiastic testimonials. People paid for them, believed in them, loved them, swore by them — that is how misleading testimonials can be. People believe what they want to believe.BACK TO TEXT
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Four experts on myofascial pain syndrome (MFP) performed trigger point examinations and 4 experts on fibromyalgia performed tender point examinations on 3 groups of subjects (7 patients with fibromyalgia, 8 with MFP, and 8 healthy persons) while blinded as to diagnosis. Local tenderness was common in both disease groups (65-82%), but was elicited in a greater proportion of MFP experts' examinations (82%). Active trigger points were found in about 18% of examinations of patients with fibromyalgia and MFP, but latent trigger points were rare in all groups. A more liberal definition of trigger point, however, resulted in a 38 and 23% positive rate among patients with fibromyalgia and MFP, respectively. Taut muscle bands and muscle twitches were common (50 and 30%, respectively) and noted equally in all 3 diagnostic groups. Problems with reliability were identified for taut bands, muscle twitch, and active trigger points. Our data are exploratory and tentative, but suggest that attention to definition and reliability are required to advance our knowledge of these common syndromes.
Description and video of a classic mind-blowing psychology experiment that demonstrated “inattentional blindness” — such as not noticing a gorilla walk through a group of people you’re watching.
Chabris & Simons book is excellent read: see The Invisible Gorilla.BACK TO TEXT
I do enjoy reliability studies, and this is one of my favourites. Three chiropractors were given twenty patients with chronic low back pain to assess, using a complete range of common chiropractic diagnostic techniques, the works. Incredibly, assessing only a handful of lumbar joints, the chiropractors agreed which joints needed adjustment only about a quarter of the time (just barely better than guessing). That’s an oversimplification, but true in spirit: they couldn’t agree much, and researchers concluded that all of these chiropractic diagnostic procedures “should not be seen … to provide reliable information concerning where to direct a manipulative procedure.”BACK TO TEXT
This paper describes a failed initial attempt to confirm that the diagnosis of trigger points is reliable, and then goes on to report on greater success with practitioners who were more thoroughly trained. Unsurprisingly, the authors conclude that some diagnostic signs are more difficult to reliably detect than others, and some trigger points are harder to diagnose in some muscles than others.BACK TO TEXT