Edit 7/20/17: See comments from the author about this review. In particular, he believes I overstated his claims, sometimes by a lot.
This is part of an ongoing series assessing where the epistemic bar should be for self-help books.
Thesis: increasing your physical capabilities is more often a matter of teaching your neurological system than it is anything to do with your body directly. This includes things that really really look like they’re about physical constraints, like strength and flexibility. You can treat injuries and pain and improve performance by working on the nervous system alone. More surprising, treating these physical issues will have spillover effects, improving your mental and emotional health. A Guide To Better Movement provides both specific exercises for treating those issues and general principles that can be applied to any movement art or therapy.
The first chapter of this book failed spot checking pretty hard. If I hadn’t had a very strong recommendation from a friend (“I didn’t take pain medication after two shoulder surgeries” strong), I would have tossed it aside. But I’m glad I kept going, because it turned out to be quite valuable (this is what triggered that meta post on epistemic spot checking). In accordance with the previous announcement on epistemic spot checking, I’m presenting the checks of chapter one (which failed, badly), and chapter six (which contains the best explanation of pain psychology I’ve ever seen), and a review of model quality. I’m very eager for feedback on how this works for people.
Chapter 1: Intro (of the book)
Claim: “Although we might imagine we are lengthening muscle by stretching, it is more likely that increased range of motion is caused by changes in the nervous system’s tolerance to stretch, rather than actual length changes in muscles. ” (p. 5).
Overstated, weak. (PDF). The paper’s claims to apply this up to 8 weeks, no further. Additionally, the paper draws most (all?) of its data from two studies and it doesn’t give the sample size of either.
Claim: “Research shows the forces required to deform mature connective tissue are probably impossible to create with hands, elbows or foam rollers.” (p. 5).
Misleading. (Abstract). Where by “research” the Hargrove means “mathematical model extrapolated from a single subject”.
Claim: “in hockey players, strong adductors are far more protective against groin strain than flexible adductors, which offer no benefit” (p. 14).
Misleading. (Abstract) Sample size is small, and the study was of the relative strength of adductor to abductor, not absolute strength.
Claim: “Flexibility in the muscles of the posterior chain correlates with slower running and poor running economy.” (p. 14).
Accurate citation, weak study. (Abstract) Sample size: 8. Eight. And it’s correlational.
[A number of interesting ideas whose citations are in books and thus inaccessible to me]
Claim: “…most studies looking at measurable differences in posture between individuals find that such differences do not predict differences in chronic pain levels.” (p. 31).
Accurate citation. (Abstract). It’s a metastudy and I didn’t track down any of the 54 studies included, but the results are definitely quoted accurately.
Chapter 6: Pain
Claim: “Neuromatrix” approach to pain means the pattern of brain activity that create pain, and that pain is an output of brain activity, not an input (p93).
True, although the ability to correctly use definitions is not very impressive.
Claim: “If you think a particular stimulus will cause pain, then pain is more likely. Cancer patients will feel more pain if they believe the pain heralds the return of cancer, rather than being a natural part of the healing process.” (p93).
Correctly cited, small sample size. (Source 1, source 2, TEDx Talk).
Claim: Psychological states associated with mood disorders (depression, anxiety, learned helplessness, etc) are associated with pain (p94).
True, (source), although it doesn’t look like the study is trying to establish causality.
Claim: Many pain-free people have the kinds of injuries doctors blame pain on (p95).
True, many sources, all with small sample sizes. (source 1, source 2, source 3, source 4, source 5)
Claim: On taking some cure for pain, relief kicks in before the chemical has a chance to do any work (p98)
True. His source for this was a little opaque but I’ve seen this fact validated many other places.
Claim: we know you can have pain without stimulus because you can have arm pain without an arm (p102).
True, phantom limb pain is well established.
Claim: some people feel a heart attack as arm pain because the nerves are very close to each other and the heart basically never hurts, so the brain “corrects” the signal to originating in the arm (p102).
First part: True. Explanation: unsupported. The explanation certainly makes sense, but he provides no citations and I can’t find any other source on it.
Claim: Inflammation lowers the firing threshold of nociceptors (aka sensitization) (p102).
Claim: nociception is processed by the dorsal horn in the spine. The dorsal horn can also become sensitized, firing with less stimulus than it otherwise would. Constant activation is one of the things that increases sensitivity, which is one mechanism for chronic pain (p103).
Claim: people with chronic pain often have poor “body maps”, meaning that their mental model of where they are in space is inaccurate and they have less resolution when assessing where a given sensation is coming from (p107).
Accurate citation (source). This is a combination of literature review and reporting of novel results. The novel results had a sample of five.
Claim: The hidden hand in the rubber hand illusion experiences a drop in temperature (p109).
Accurate citation, tiny sample size (source). This paper, which is cited by the book’s citation, contains six experiments with sample sizes of fifteen or less. I am torn between dismissing this because cool results with tiny sample sizes are usually bullshit, and accepting it because it is super cool.
Claim: “a hand that has been disowned through use of the rubber hand illusion will suffer more inflammation in response to a physical insult than a normal hand.” (p. 109).
Almost accurate citation (source). The study was about histamine injection, not injury per se. Insult technically covers both, but I would have preferred a more precise phrasing. Also, sample size 34.
Claim: People with chronic back pain have trouble perceiving the outline of their back (p. 109).
Accurate citation, sample size six (pdf).
Claim: “Watching the movements in a mirror makes the movements less painful [for people with lower back pain].” (p. 111). Better Movement. Kindle Edition.
Accurate citation, small sample size (source).
Reminder: the model is that pain and exhaustion are a product of your brain processing a variety of information. The prediction is that improving the quality of processing via the principles explained in the book can reduce pain and increase your physical capabilities.
Simplicity: Good. This is not actually simple model, it requires a ton of explanation to a layman. But most of its assumptions come from neurology as a whole; the leap from “more or less accepted facts about neurology” to this model is quite small.
Explanation Quality: Fantastic. I’ve done some reading on pain psychology, much of which is consistent with Guide…, but Guide… has by far the best explanation I’ve read.
Explicit Predictions: Good, kept from greatness only by the fact that brains and bodies are both very complicated and there’s only so much even a very good model can do.
Useful Predictions: Okay. The testable prediction for the home-reader is that following the exercises in the back of the book, or going to a Feldenkrais class, will treat chronic pain, and increase flexibility and strength. Since the book itself admits that a lot of things offer short term relief but don’t address the real problem, helping immediately doesn’t prove very much.
Acknowledging Limitations: low. (Note: author disputes this, and it’s entirely possible he did and I forgot). GTBM doesn’t have the grandiose vision of some cure-all books, and repeatedly reminds you that your brain being involved doesn’t mean your brain is in control. But there’s no sentence along the lines of “if this doesn’t work there’s a mechanical problem and you should see a doctor.”
Measurability: low. This book expects you to put in a lot of time before seeing results, and does not make a specific prediction of the form they will come in. Worse, I don’t think you can skip straight to the exercises. If I hadn’t read the entire preceding book I wouldn’t have approached them in the correct spirit of attention and curiosity.
Hmmm, if I’d assigned a gestalt rating it would have been higher than what I now think is merited based on the subscores. I deliberately wrote this mostly before trying the exercises, so I can’t give an effectiveness score. If you do decide to try it, please let me know how it goes so I can further calibrate my reviews to actual effectiveness.
You might like this book if…
…you suffer from chronic pain or musculoskeletal issues, or find the mind-body connection fascinating.
This post supported by Patreon.
8 thoughts on “Epistemic Spot Check: A Guide To Better Movement (Todd Hargrove)”
I found myself repeatedly wishing that you would address the effect size in addition to sample size. There are some things I will believe strongly even with small sample size. For example with the ‘hidden hand experiences more inflammation’ one, if the hand god super red and pulsing, I would take a sample size of like 4 seriously.
I would find statements like ‘large effect size but small enough to be suspicious’ and ‘small sample but gigantic effect’ useful. I’m guessing most of these are in the first category, but it would be cool to know.
This is super helpful, thank you.
Great post! I’ve met Todd Hargrove (who lives here in Seattle) and enjoyed his book. I tried the exercises but in a half-hearted way, so I can’t attest to how useful they are.
I’m the author of the book and wanted to say thanks very much for the review, and also to offer a response. I’ll start with some general comments and then address specific points.
First, this post calls into question many claims because the citations do not fully prove them. But it shouldn’t be assumed that claims are false because citations are not proofs. The subject matter is complex, and the claims are based on a broad evidence from many different sources, not just the one study cited.
Second, you often ignored my caveats. For example, if I say something is “probably” true, I am admitting the evidence remains ambiguous or incomplete.
Here are some specific responses:
The thesis: You have stated it pretty well, but far too strongly. I did not argue that improving movement is “more often” about the nervous system than structure. Instead, I said that the nervous system is often neglected and we need more balance. For example, from the Intro:
“the focus [of this book] . . .does not imply the structure of the body is unimportant, or good movement is ‘all in your head.’ Far from it! The structure and health of the musculoskeletal system is essential for quality movement, just as a mechanically sound car is required for safe driving. But there are many books on how to improve the structure of the body . . . .This book is an attempt to provide some much needed balance.”
The spot check on stretching: You judge the claim to be “overstated and weak.” But note the caveat: I said it is “more likely” that nervous system tolerance explains most flexibility gains from stretching. Part of the reason for this qualification is (1) we still don’t know exactly what stretching does (as stated in the paper cited). And (2) most people don’t stretch hard and long enough for what experts believe is probably necessary to create plastic changes in the tissues.
The claim on fascia: Note again the caveat – structural change to fascia from hands and elbows is “probably” impossible. I cited one study in support (there is another), but the best support is based on basic biological plausibility. For example, see the following article: https://www.painscience.com/articles/does-fascia-matter.php.
The claim about flexibility vs. strength for injury protection: I will admit the hockey study is weakly powered, but once agin, a weak citation does not imply a false claim. A better citation would include studies showing that flexibility training does nothing to prevent injury, and that strength exercises (e.g Nordic ham curls) are protective. Within the context of the paragraph, there is nothing misleading here.
Acknowledging limitations: You gave me a poor rating based on the claim that “there’s no sentence along the lines of ‘if this doesn’t work there’s a mechanical problem and you should see a doctor.” There’s actually many sentences like that! Before discussing general strategies for treating pain, I state:
“First, a word of caution. Reading the strategies below is no substitute for getting medical attention. Make sure to see a qualified medical professional for treatment of any pain.”
And later: “Identifying an exact source of nociception and determining an effective remedy is often very difficult. There are many tough questions. . . . Answering these questions is far beyond the scope of this book, and requires significant training and expertise.”
In regard to the illustrated exercises I state: “These represent ONE example of how the strategies listed in the preceding chapter can be applied.”
Measurability: You rated this poor because I expect people to put in a lot of time before seeing results. But the book does not expect readers to spend time doing the exercises. It expects them to understand the basic principles, and then use that understanding however they want. The exercises are shown as ONE example about how to apply some of these principles. There is no suggestion that they will work for everyone, because pain is complex and always unpredictable! In short, this book is not intended to offer a self-help recipe, but an educational discussion of a complex topic. There are no easy answers.
Sorry this is long winded! If you could make some changes to the review based on this comment that would be great. Thanks again for the review and especially the kind words about the pain explanations. Much appreciated..
Hi Todd, thanks for such a detailed and kind response. I’ve updated the post to point to your comments.
I agree that a weak citation is not counterevidence, and I hope I’m not implying it is. But I do think that knowing what citations are weak, versus strong and misleading, is useful information.
On measurability: I agree that that you’re not failing at producing quick recipes, because you’re not trying to do so. Many things are too complicated to test quickly, and the problem would be suggesting quick fixes. Good books on those subjects will get measurability: poor, because they are hard to measure. I’ve changed it to measurability: low so it sounds less judgemental, but since this is an absolute measure not a relative one, the difficulty of the subject doesn’t enter into it.
Thanks for the response and for including a reference to my comments! Two more minor whines:
Thanks for acknowledging that incomplete citation does not necessarily imply inaccuracy. But the post strongly suggests otherwise IMO. For example, you state that after the first spot check, you considered tossing the book aside.
As to the “Acknowledging Limitations” section, I would appreciate an edit reflecting a correction. Saying “the author disputes see below” makes it sound like there is a dispute, and I don’t think there is one, right?
I consider many weak and especially misleading citations to be worse than no citations at all. I think your book really shines in other ways and the fact that it failed spot checking and went on to be valuable made me reconsider how I evaluate books, but that doesn’t make the citations strong.
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