The Thinking Practitioner Podcast:
Episode 69: Back Pain, Stiffness & Fascia (with Stuart McGill) 

Whitney Lowe:

Welcome to The Thinking Practitioner Podcast.

Til Luchau:

A podcast where we dig into the fascinating issues, conditions, and quandaries in the massage and manual therapy world today.

Whitney Lowe:

I'm Whitney Lowe.

Til Luchau:

And I'm Til Luchau. Welcome to The Thinking Practitioner.

Whitney Lowe:

Welcome to The Thinking Practitioner.

Til Luchau:

The Fascia Research Society invites the listeners of The Thinking Practitioner Podcast to the sixth international Fascia Research Congress in Montreal, September 10th through 14th, 2022. Eight keynote speakers, including our guests today, over 60 parallel session talks and posters, 15 workshops, including one that I'm giving on inflammation in fascia on September 11th, and a two-day fascia-focused dissection workshop are all on offer. The full congress schedule is out now. Register for the sixth international Fascia Research Congress today at fasciaresearchsociety.org. Hey, Whitney. We have a special guest today. Who's with us today?

Whitney Lowe:

Yes, we are very honored today to have Dr. Stuart McGill with us. He is a distinguished professor emeritus from the University of Waterloo, where he was a professor for 30 years. His research investigated issues related to mechanisms of back pain, how to rehabilitate back pain in people, and enhance injury resilience and performance. So people from all over the world, high professional athletes, professionals, patients from all over the world, seek out his help on musculoskeletal back pain issues. And he has produced over 245 peer-reviewed scientific journal papers, several textbooks, and many international awards, including the Order of Canada in 2020 for leadership in the back pain area. And he is currently the chief scientific officer for BackFitPro. And we are absolutely delighted and honored to have Dr. McGill with us. So welcome, Dr. McGill. Thanks very much for joining us today.

Stuart McGill:

Well, first of all, thanks so much, Whitney and Til. And I hope from now on it can be Stu. We'll dispense with the doctor and professor stuff.

Whitney Lowe:

Okay. All right, then, yeah. We'll do that. So thanks again so much for joining us. And we'll talk a bit more about some of the other things that you've done here as we get through this conversation here, but I wanted to really jump right in here so we can take the meat of our time to really get into some good stuff here. I wanted to start with one question here that has fascinated me. I've been looking forward to having a chance to talk with you about this for a very long time. So in any respect, I heard you say one time that there is no such thing as nonspecific back pain. And I believe you had mentioned that was mainly in many instances because people had not done a thorough enough investigation to identify what was really causing a primary pain complaint. So, could you comment on that idea a little bit?

Stuart McGill:

Yes. The essence of that question and debate is certainly something I understand, but it's not new. You think back to the early 1900s, the famous Einstein, Niels Bohr debates on relativity. And in that debate, Einstein famously quoted, "God does not play dice with the universe." In other words, it's a deterministic system with cause and effect, and it has some specificity. But what he did introduce was a new set of equations that people began to understood and explained this very deterministic world. Going back over 30 years ago, I realized that I was just starting to see patients myself, and they would come in with these diagnoses of nonspecific back pain. And I was seeing that nonspecific back pain begged nonspecific treatments. Nothing worked or everything worked.

Stuart McGill:

So I set aside, on a little bit of a mission, I suppose, to create what I ended up calling the six pillars of evidence. The first was an in vivo, or sorry ... well, an in vitro laboratory, where it was set up to measure live people with pain, without pain, some doing extraordinary things, lifting world record loads off the ground, sprinting fast, et cetera. We would measure muscle activity and use various methods to transform that into measures of force and stiffness. We would measure through modeling disc deformation, ligament strain. And I even had a lumbodorsal fascia, you'll be happy with me, in that first model of 40 years ago, almost to this year. In any case, trying to create stress maps.

Stuart McGill:

And it was so interesting that the regions of highest stress was where people reported the most pain. Then we decided, "Well, we better see what these stresses do to real spines." So we would take cadaver spines in the in vivo laboratory, sorry, in vitro, and apply these loads, and see the damage that was created in the tissue. So we could link one to one overloads of compression or bending or extension, or whatever it happened to be. And it created very specific types of injuries. Then we realized, "Well, let's now look at epidemiologically-based clusters of people, athletic groups, occupational groups, who have similar exposures to these loads." And it was so interesting that the injuries and the pain patterns clustered around sports and jobs. So, that was the third part.

Stuart McGill:

Then we ran clinical trials seeing if we could subcategorize these pained people into specific groups, and we would try specific types of treatment. And the odd thing about our research clinic that the dean asked me to start at the university, we didn't have one at the time, we followed up with every patient we ever saw. So we know the subcategory that they fell into. We know whether they complied with our recommendations or not. And we know how they were after two years, in a follow-up. So that was both the fourth and the fifth part of the pillars, running the experimental clinic.

Stuart McGill:

And then we also did, let's see, clinical trials, clinics and some experimental runs with military groups, different sports teams, et cetera. So, can you imagine taking a much simpler system than a human, let's take a car, even though it has, I don't know, 20-some-odd onboard computers, taking that to your car mechanic and saying, "My car has non-specific dysfunction." And the mechanic says, "Ah, with all nonspecific dysfunction, we change the engine." So, you need specificity to match a evidenced intervention. So that then led to our assessment to try and create very specific low back pain subgroups. It starts with simply observing the person.

Stuart McGill:

As we begin an extensive interview, it simply starts, it's open-ended, "Tell us why you're here." And people will give you gold if you let them. For the first time in their lives, they tell you, "Well, I get up in the morning. I have this stiffness." And no one has ever asked them to look at their mattress, for example. And then we might have a follow-up question: "Do you have sharp pains in your back when you roll over?"

Stuart McGill:

"Yes, I do." It's interesting that that answer correlates to the amount of joint instability that they have. So the movement catches and whatnot, they're not nonspecific and random. They are very specific. Then we create a provocative testing session to test the hypotheses based on the pattern recognition that we did listening to their stories. Then we converge on the motions, the postures, the loads, the activities that trigger their pain. We know what doesn't trigger their pain. And then we try and create movement hacks and test alternative hypotheses to see if we can, in some cases, immediately change the pain pattern. That's what we call the antidote.

Stuart McGill:

So there's a little bit of a start, I suppose. But I will say this as well, and I know this is getting to be a bit of a long-winded answer, once we show the individual that their pain is not specific, but in fact it's very specific, generally, two reactions occur. One is they become, "Thank goodness. For the first time I understand my pain now. I'm not crazy." And in fact, they become psychologically empowered: "Ah, I've got an understanding and a strategy of how to control this." But conversely, some also get very angry and they say, "I've gone through all of this suffering unneedlessly, and yet you're showing me a strategy that empowered me to have some direction on this pain that I thought was nonspecific." So there's a little bit of a start.

Whitney Lowe:

Yeah. So let me follow up with that just a little bit, too. My passion and interest in this field in arena is a lot around accurate assessment of soft tissue pain and injury problems. And this is one of the reasons that I wanted to delve into that a bit more. And it sounds as if you're saying that there is really a need in many instances for a more detailed type of assessment process with many of these people who come in with pain problems. And one of the things I want to hear your perspective on, there seems to have been, at least in my perception, a bit of a backlash both in our field and in a number of other fields, in physiotherapy and some other places too, in recent years, around with sort of this proliferation of interest and focus on pain science, looking at pain as this more complex bio psychosocial problem.

Whitney Lowe:

And I've heard a number of clinicians say things like, "Oh, I don't need to go through that detailed assessment anymore, because we need to just treat people's pain more holistically." And it seems like that has led to less emphasis in some instances on assessment. And I'm curious about your thoughts about that, if you think that's a perspective that's missing some things, or is that a decent way to be focusing on these things?

Stuart McGill:

No, I disagree with it very strongly. My first degrees were in the department of kinesiology. And I ended up as a professor of spine biomechanics in the department of kinesiology. And I was the chair of the department for a number of years. The motto of the department was From Cell to Society. We had professors of sociology, psychology, physiology, anatomy, biomechanists, neuroscientists. We had surgeons, et cetera. We covered the waterfront. And I know some people who don't know our background say, "Oh, well, McGill is all mechanical and doesn't appreciate this sort of work."

Stuart McGill:

My PhD mentor worked in industry and was one of the leaders in measuring stressors on workers from valid and robust psychosocial inventories, personality profiles, et cetera, together with fairly robust biomechanical measures. Then he would assess those workers all doing the same job. So he did a large study at General Motors, for example, because the work population was in the hundreds of people all doing the same job, so the physical exposure was the same. There was another study done at Boeing aircraft, people who rivet aluminum sheets together, all doing the same job. As it turned out, those who ... Well, I'll just back up one more layer here.

Stuart McGill:

The dominant determinant of who had musculoskeletal disorders, of which back pain was the most dominant, were those who had the greatest mechanical exposure closest to the physical tolerance of their tissues. Genetics also mattered. Body type mattered. Size of their spine mattered. A thick spine breaks sooner when it's bent, but it has a higher tolerance to compression, just like a tree. You can bend the thin branch back and forth without a lot of stress, but it will break under compression, whereas a bigger tree breaks much sooner when you bend it to the same degree, but it can support much more compression.

Stuart McGill:

So the mechanics dominated the instigation of the disorder and pain. The genetics predisposed, certain people to that. And how they handled the pain was influenced by the psychosocial milieu. Now, when you then use statistics to quantify the relative role of those three things, mechanics and mechanical exposure dominated in some. But what happens is in the scientific studies, particularly in the last 10 years, the psychosocial pain science groups and whatnot look at those variables and they don't look at the mechanical or some of the genetics. Scientists find what they look for, so of course they find a statistical support for psychosocial variables. But every study that I know of that's measured the relative role of all three, show the mechanics dominate. So in that way, we can't dismiss any of them, but we have to put it in that context. So, does that help answering that specific question?

Whitney Lowe:

Yeah, certainly. Yeah, absolutely. Thanks.

Til Luchau:

It does. And your reputation as one of the world's leading back experts was really built on the specific research you did around the mechanisms you've done for many years over the mechanisms of back injuries. And then your detailed patient intake process of really helping narrow it down to specific movements, say, that could really even provoke the pain. And so then you've somehow been championed as the Mr. Mechanics, Mr. Biomechanics: "He says the tissues matter, and we got to pay attention to those." So then help me understand what you called virtual surgery, because I don't think it's necessarily paradoxical, but you're doing something that isn't tissue-based, and having some interesting results.

Stuart McGill:

Yes. As I mentioned with our experimental research clinic at the university, on intake, we would assess the back pained person. And if they fell into this category, Til, you will see the foundation of virtual surgery. If they had tried everything, and this is what they had heard from their clinician, "You've tried everything. You've been to the chiropractor. You've been to the therapist. You've been to the Rolfer. You've been to the osteopath. You've seen a neurosurgeon," et cetera, et cetera. "None of it worked. Therefore, the last hope for you is surgery."

Stuart McGill:

So if that's the category that that person fell into, we would assess them, try and understand the specificity of their pain, show them how to avoid their pain and wind it down. In other words, when you examine the role of surgery, they have to stop doing the mechanical things that, unbeknownst to them, were keeping them sensitized. So it was an automatic way to desensitize the system. It was forced rest. And I'll give you an example. You might have a woman, 35 years of age, two young kids at home. And she says, "I have got to go and ride the elliptical trainer for 40 minutes every day at the gym. Otherwise, I will become so stressed, that something bad is going to happen." In other words, she's a addict to that 40-minute exposure of load. But then when we do the provocative testing, we prove to her that, "That is the cause of your pain. Let it rest for a while."

Stuart McGill:

She says, "Well, I can't." Then you're into a bargaining session. Well now, you have to play hard ball. And how do you deal with an addict? You've got to have some way to break the addiction. In any case, we then ... I didn't come up with virtual surgery, but I've certainly championed it. So for that particular person, as it turned out, we'll be very dramatic and say, "Look, there's your surgery. Now, are you going to the gym tomorrow to ride the elliptical?"

Til Luchau:

You pretend like you did the surgery. You do something where it says, "Let's pretend like that happened."

Stuart McGill:

And now recover like a postsurgical patient, now here's the [inaudible 00:18:08]-

Til Luchau:

But now really recover, really go through the recovery as if you'd had it, yeah.

Stuart McGill:

Right. And now, here's the interesting fact. We would then follow up with those people. Within two years, 95% of them reported that they were glad they didn't have the real surgery. And I mean, there you have it. Now, I know that was a fact. Now, not every subcategory we have is that successful, of course, but that was our most successful category following the approach of virtual surgery.

Til Luchau:

Let me see if I get it right. So people that were at their wits' end, they tried everything, were contemplating surgery, in line for surgery, you said, "Let's try this. Let's pretend you have the surgery." Let's say, "Here it is. Now, go ahead and do everything you would've done to recover from that surgery," including, it sounds like, mostly rest. And you're saying that later-

Stuart McGill:

Correct. Well, it was rest to create a desensitization of the pain, and then a plan of graded exposure to adapt their bodies back to be robust enough to do what it is they needed to do. Now, that might have been getting back to work. Their passion might have been cycling, road cycling, or going for hikes, or whatever it happened to be. And if you know our history, there's been many a world class athlete who we have done this with. We have restored full athleticism so that they've returned to set world records in speed, power, strength, sport.

Til Luchau:

Using this approach of, "Let's put you through the 'virtual surgery,' and help you go through what you would've gone through, just without the knife."

Stuart McGill:

Well, a little bit more, if they're going to compete at the world level. We have to adapt their bodies to withstand those. But we all understand tissue adaptation. The language of cells and adaptation is force and pressure. That's what causes the adaptation. Well, we can get into a psychological cofactor there if you wish, but it's dominated by force and pressure.

Til Luchau:

Can I just go a little bit off piece to this one? Can I have both of your permission to follow this line a little bit?

Whitney Lowe:

Yeah.

Stuart McGill:

Sure. Yeah. Yeah, of course.

Til Luchau:

Okay. So I'm really interested in this too, and just listening to a couple of your interviews as I got ready for our conversation, tell me if I'm wrong, but I think you're working with people's attitude toward what they're doing as well, like I'm thinking about the quote attributed to you, like if you approach something ... You were asked something about like, "What's the right position for your spine or your legs under your spine?"

Til Luchau:

And you said, "Imagine you're about to dance," or you said ... Just so many of your recommendations around the "correct way to do it" had to do with a perspective or attitude toward that movement. Am I on track at all around that?

Stuart McGill:

Well, yeah, partially. If a person has no pain, I don't have much of a guideline to go with or to give them. But when they have pain, remember, in our world, it's no longer nonspecific, it's quite specific, that now gives me a roadmap. And I'll say, "Look, here, we've documented what is triggering your pain. And if you can avoid that and allow the desensitization to occur, you've now created some margin for error. And you can misbehave a little bit. And our job is to get you back so you can misbehave quite a bit. But right now, a small misbehavior, you are going to pay for."

Stuart McGill:

And if you want to get into the fascial world, for example, I had a patient not too long ago, where they had nonspecific back pain until they arrived here. And they really had some nasty nerve tethering. And we documented that. We were able to create stresses and releases of very specific nerve roots, but then ... I've been a real fan, I suppose, of Tom Myers' work over the years. So then I started to play with fascial tightening and releasing. Now, this person had some surgery. And I am convinced there was now a mechanical tether from the fascia to the nerve root. It wasn't hung up on a disc or a bit of arthritic bone. Now, this had never been shown to them, but when I asked them, "Put your arm over your head. Now, push your heel towards the ceiling, and go into internal, external rotation around the shoulder." Do you know, this sent a zinger down their leg, down the femoral nerve root. And what am I doing? I'm playing with the fascial train.

Stuart McGill:

So, these are the things I'm going to talk about in Montreal. They didn't have nonspecific back pain. It was so specific, but no one had taken the trouble to act like Sherlock Holmes and go where no other detective had ever gone before. And you cannot believe the psychological unleashing that they just expressed right in their ... "I'm not crazy. There is a reason for my pain. I get it. Now I can modulate that. Where I place my hand now determines the zingers down my leg." And it was perfectly repeatable. Anyway, you might enjoy that, Til.

Til Luchau:

I do appreciate that, sir, because that's a model I use quite a bit, the nerve tethering or the fascial glide around the nerve roots in something like sciatic pain. And then the empowerment that people feel when they can dial it down to a movement that either provokes or relieves the pain gives us a sense of control also, so we can do something about it, and often, it does.

Stuart McGill:

I have a follow-up question for you.

Til Luchau:

All right.

Stuart McGill:

So, I know your background. I see quite a number of world class rowers. I cannot palpate their spinous processes, because of the heaviness of the fascia. The adaptation that they have created is astounding. And so, how do you handle that, with such an enormous, tough tissue that puts them on the one percentile of being a human?

Til Luchau:

Yeah. Well, maybe this is the background of my questions to you about virtual surgery and the attitude piece. My target is often not their fascia, but their pain, their disturbance. And there's lots of ways to work with people's pain and disturbance without necessarily needing to rake through every fiber of their fascia, including movement, including carefully modulated ... You said graded exposure, those kinds of things. That really helps shift someone's experience of pain, for example.

Stuart McGill:

I remember a famous quote of Janda's mentor, a urologist named Carol Levitt. And he said, "He who treats the site of pain is lost." Well, I wouldn't necessarily agree with that in all cases, but certainly, we live in a mechanical linkage. And a disturbance in one area will work its way through the linkage.

Til Luchau:

Yeah, that's right. And by disturbance, I'm saying their experiential disturbance of being in pain. And then, the mechanical puzzle of what is linked to what, and where is this, what are the origins of that, is a fascinating puzzle to untangle.

Stuart McGill:

Yeah, it is.

Til Luchau:

Whitney, you had a question about Janda's stuff.

Whitney Lowe:

Yeah, we did. And I was pondering, too, that quote from Carol Levitt, because I'd heard that years before too. And maybe perhaps a more accurate way to reframe that would be, "He who focuses exclusively on where that site of pain is might be lost." But yeah, I [inaudible 00:26:42]-

Stuart McGill:

[inaudible 00:26:42] And I mean, and I just got to this in, in the structure integration tradition, Ida Rolf, one of her most famous quotes was, "Where you think it is, it ain't." So it was almost the other needle was at the other end of the dial there. She's saying it's never where you think it is, which just another place on that continuum. But go ahead, Whitney. Sorry about that.

Whitney Lowe:

Yeah, no problem. We mentioned Vladimir Janda a moment ago. And I was curious for your take on this, because most of us dealing with soft tissue work in depth have been influenced or certainly encountered his models over the years. And there's been some recent research and debate around the primary models of the upper and lower cross syndromes. And I'm curious for your take on that, in terms of the accuracy of those particular models. What are your thoughts about that?

Stuart McGill:

Well, I had the chance to put on a clinical session with Vladimir Janda. This was a session set up by Craig Levenson in Buffalo. And I was somewhat familiar with his teachings, but the first lesson I learned that day was to just observe him. As clinical delegates would file into the lecture hall, he was watching them. He was watching them all and doing pattern recognition. And he knew who he was going to bring down to do demonstrations on. Those patterns were that overt, that he could see with his eye just coming into the room. And that was a lesson in pattern recognition that I never thought or lost, shall we say.

Stuart McGill:

I can only comment on the lower cross syndrome, because that's what we investigated. What Janda said in the lower cross syndrome was that pain corrupts. Those with back pain, some of them, get a ... now, if I can remember what his terms were. He said, "It causes muscle weakness on one side of the joint and tightness on the other." But my impression and what I came to appreciate was he really meant neurogenic inhibition of the hip extensors and neurogenic facilitation of the hip flexors. So, that took me then to an experiment on neurogenic facilitation.

Stuart McGill:

One of my graduate students, Dr. Stephanie Freeman, who was a former sprinter herself, interestingly enough, we worked with an interventional radiologist who was doing arthrogenic ... sorry, what did he call those, now? Therapeutic arthrograms. He would fill up the joint capsule of the hip joint and burst it just a little bit in people who were pre-arthritic, but not ready for a full hip replacement yet. It's a very painful ... I've had one on my shoulder, to increase the mobility. And it's an interesting experience, but nonetheless, it's a very painful experience. Prior to the pain induction, we measured the people walking, doing hip thrusts and all kinds of things, measuring the quadricep muscle activation, the gluteal mead, the glute max, the hamstrings, and what were their relative contributions to creating hip torque. When the hip pain was induced, and I now have come to the realization that it's back pain as well, the gluteal muscles in every single one of those candidates became inhibited. The motor control system shifted the responsibility of the glutes to the hamstrings. And it slowly returned as the pain was released.

Stuart McGill:

Now, that study has been misinterpreted by people who've never done this kind of science before. They've talked about it, I guess, on social media, which is a little bit of a shame. So maybe that's why you're getting a little bit of a blow back on that. But Janda was right in that regard, in terms of neural facilitation, he used the term hip flexors. We found out it wasn't the hip flexors. It was very specifically psoas.

Til Luchau:

Psoas. Iliopsoas.

Stuart McGill:

Yeah, no, not iliopsoas. There's no such muscle. Iliacus is very separate from psoas. They've got totally different functions. Now, they do share a little bit of a common tendon, but you realize, Til, that I'm one of the few people in the world that's measured both of those muscles. We've implanted electrodes in them and measured them. They're very different muscles, and the brain goes and recruits them to perform different functions. So, the iliacus is simply a hip flexor. The psoas is a hip flexor, but it acts like ... you can think of it as a wet sock of cement, either side of the lumbar spine.

Stuart McGill:

But when you flex the hip, it stabilizes and holds steady the lumbar spine. If you look at a sprinter, for example, the stresses to their lumbar spine are really mitigated by the cement-like buttressing of psoas. So they're very, very different muscles. Sorry for that, but there you go.

Til Luchau:

I love it.

Stuart McGill:

But it was actually psoas that was the facilitated muscle among the hip flexor group. And I might say that it's not in every back pained or hip pained person, but it's in a few. And it can be extremely substantial in some, and of non-interest in others.

Til Luchau:

Can I stick in a comment there, or a question, Whitney?

Whitney Lowe:

Yeah. Yeah, go ahead.

Til Luchau:

So, how does that translate, Stu, in terms of position, do you think, pelvic tilt or things like that? Because Janda's model is sometimes just interpreted as a positional model, is the pelvic tilted or not, and if it's not, then it's lower crossed.

Stuart McGill:

Oh, well, I think that's a misunderstanding. He was very much about the muscle activation profiles, together with posture. And what posture does is it migrates stress from one tissue to another. That is further modulated by how the brain recruits muscles to create torques and stiffnesses in the linkage. And we can get into linkage mechanics, if you like. If I wanted to wiggle my little finger very, very quickly, I had to stiffen my hand and wrist. If I want to wiggle my wrist very quickly, I had to stiffen my elbow. In other words, the law of the linkage is that you must have proximal stiffness to unleash and allow distal athleticism. Every one of those stiffnesses has a cost in terms of joint load, et cetera. Then we get into, well, if you have insufficient mobility at a joint, it upsets the linkage, and now you must work somewhere else in that linkage to create either mobility or proximal stability. And those stress risers are often associated with pain, when you know about them and can document them.

Whitney Lowe:

So in essence, what I'm hearing here, too, is that we may have jumped the gun a little bit by just focusing on static posture here, when in essence, somebody might, in a static postural evaluation, have that typical kind of lower cross syndrome, but their functional adaptation for movement might be very different in terms of the way things are recruited or used in the activities that they're doing. Is that accurate?

Stuart McGill:

Very accurate. Yeah. I mean, I could give you a simple example of that and a more complex example of that. I think I'm-

Til Luchau:

I'm up for the simple one. I'm up for the simple example, yeah.

Stuart McGill:

Okay. Stand up straight and lift your tail, increase your lordosis. What did that just do to your thoracic spine? Now, if you had a thoracic pain trigger, by extension, your pelvic tilt just created pain in your thoracic spine, for example. So there's a really simple one. Here might be a more interesting one. Let's take a runner, a recreational runner who runs 40 kilometers a week. I'm assuming you two are Americans.

Whitney Lowe:

Yes, we are.

Til Luchau:

Mm-hmm.

Stuart McGill:

Okay. Well, let me put that into miles, then. Sorry. When are you going to join the scientific units of the world?

Whitney Lowe:

Hey, we keep asking that question too, but I don't think it's going to happen in our lifetimes.

Stuart McGill:

Okay. Let's take an American recreational runner who might run, say, 30 miles a week. They have low back pain that is increased when they sit at the computer for 20 minutes and relieved when they go for a walk for 20 minutes. So they don't have nonspecific back pain. I've already given you some details that we already know something about that pain in a specific nature. But as we probe the pain, we find out that they have a hip stiffness. If we put them on all fours and we rock their pelvis towards their heels, we see that the right hip gets hung up. And then we test it for pain sensitivity.

Stuart McGill:

And we find the labrum is sensitized with internal rotation. What is the cause of that sensitization? And we follow it through. And then when they run, we measure their foot going into pronation, stressing the knee, turning the hip into internal rotation, every single time they take a stride. Now, you do that over 30 miles a week. Their hip is so painful that when they now sit down, they sit in a way to relieve the pain in the hip capsule. They round their spine and get pain and an open [inaudible 00:37:17] or disc bulge.

Stuart McGill:

So, there might be a real house of cards for you to go through. But again, Sherlock Holmes would be able to document all of that. Now, it's time to run the clinical trial, a little bit of foot eversion. I might send them to a soft tissue guru and tune the linkage for stiffness and the compliance. And sure enough, the hip sensitivity reduces, and so does the back pain, as they said. So there would be a complex example, through the linkage.

Til Luchau:

And I'm jumping the outline a little bit here, but I can't resist highlighting what you just said about stiffness and compliance, because so many times those are juxtaposed as, either we're going to make it strong or we're going to make it loose. And this is really relevant to my work as a manual therapist, because most of my tools are about helping things relax or helping things be longer. Would you mind saying something about the role of that? Does that belong anywhere? Because so much of spinal therapy often is about getting stiffness, getting strength. My tools come out the other way, and I find ways to be helpful. But how does that fit into your thinking, Stu?

Stuart McGill:

Well, our clients, patients, athletes form a subject and equals one. So in order to answer that properly, we have to have the individual in front of us. What we are doing is tuning a linkage; strategic compliance and mobility in one place with strategic stiffness, which is the mathematical reciprocal of compliance, elsewhere. Now, the body really doesn't modulate compliance to control movement, but it does stiffness. So when a muscle contracts, it does two things. Muscle contraction creates force, everyone gets that, but it also creates stiffness. Now, that's a very non-linear function with activation, but that's how the body controls motion.

Stuart McGill:

So, I might have a back pained patient who is over-braced, over-stiffened. And I'll say, "We're going to hover. Align your ears over your shoulders, your shoulders over your hips, your hips over your knees, and the knees over the middle of your foot. Now, learn to stand with just a hover. You will notice that there's no real force involved, but is just sufficient stiffness so they don't fall down.

Stuart McGill:

If I want to throw a ball, I had to turn my hips with controlled stiffness through my core to rotate my shoulder. If I fail to do that, the stress goes into the spine rather than into the elastic tissues across the hip, across the shoulders, and the final elastic storage and recovery in the hand. All highly tuned compliance and stiffness. So stiffness, F=kx. You must have a change in posture together with a force modulated by K, the stiffness. So I'm showing you, yes, you, as a manual therapist, do change the mechanical properties of the spring to modulate its ability to store and recover elastic energy. But so does the brain. It can instantaneously change the K of the spring, the muscle, through activation.

Stuart McGill:

So, one experiment we might do is called a pogo jump. A person just stands upright and they go up and down like a pogo stick. Now, stiffen the calf muscles with high activation. You won't move. Decrease the activation, you just fall into the ground. But when you get the tuning right, you create mechanical resonance. And all of a sudden, you become a pogo stick, very efficiently. And now, I've just described the gait of a jumping kangaroo. A kangaroo is highly inefficient when it walks, but when it bounds, it tunes the mechanical stiffness, becomes highly efficient. And it actually consumes less oxygen when it's bounding along versus walking, because its mechanical linkages is not designed for that. So do you see how ... Oh, I wish we had a couple of beers, a jar of peanuts, and we could really have fun together getting into the nuances. These are never-ending discussions.

Til Luchau:

And a pogo stick. I'd put a pogo stick in there. Yeah.

Stuart McGill:

Yeah. I mean, this is how I used to teach. We had fun in lectures. But anyway, there's a little bit of a thought pattern on not only passive modulation of stiffness and compliance, but active, as well.

Til Luchau:

The way the brain controls contraction, which is interesting. You're saying the body doesn't modulate compliance. You're saying the only active thing the nervous system does is contract something, I'm assuming you're meaning.

Stuart McGill:

No, I didn't say that at all, actually. Oh yeah, we did an experiment. Well, just a moment now because, again, I know who you are, and you might really appreciate this. We took a group of men and women, university student aged men and women, and we had them to simply slouch on a stool. They flexed their neck, their full spine, and just sat slouched like that for 20 minutes. We then got them to stand up and remove the chronic stress on the passive tissues, the fascia, the ligaments, et cetera, of their spine. Even after half an hour, Til-

Til Luchau:

I'm doing that, by the way, I'm sitting up as you speak. Yeah.

Stuart McGill:

... the residual stiffness had not yet returned to the men. It took well over half an hour for those men to regain their normal stiffness. The women regained it much faster. I presented this at the World Congress on Biomechanics. And there was a very well-known neuroscientist and biomechanist in the audience, a guy named Roger Enoka. He wrote a textbook on neuromechanical something or other. I'm sorry, I forget.

Whitney Lowe:

Yeah, I've read that. Neuromechanical Basis of Kinesiology, I think was what it was.

Stuart McGill:

That's it. Now, Roger is no slouch. Roger's an outstanding scientist. And he put up his hand and he said, "Why the difference between men and women?"

Stuart McGill:

And I said, "I don't know, I've wondered, but I don't know."

Stuart McGill:

And he said, "We have some evidence to suggest that women have the neurological ability to modulate ligament stiffness." Now, we know they have the hormonal ability to modulate ligament stiffness with the hormone relax and then whatnot in the whole childbirth process. And now, you'd have to ask Roger more about what he meant by that. But there's so much that we don't know. And I just thought you might be interested in that as something to follow up on.

Til Luchau:

I am. I appreciate that. And the women were able to return to a stiffness sooner, you're saying?

Stuart McGill:

That, we documented much sooner. So, if you get a fella who's been sitting ... And I used this actually in a consulting case that I did with ambulance drivers, emergency workers. They were sitting in the ambulance, driving to the accident scene or the scene where they were required, sitting slouched in the ambulance chair. Now, they got there and there was a 400-pound heart attack victim in the bathtub. Now, you got to admit, that's a tough lift. Would you like to do it after sitting slouched for half an hour in an ambulance, or would you like to warm up your back just a little bit now? Of course, we said, "Well, we're going to put a lumbar support in that ambulance and not allow those mechanics to occur," because we documented that male will be carrying that residual stress and strained passive tissues in their back for at least the next half an hour; not so in women, apparently.

Whitney Lowe:

Yeah, interesting.

Til Luchau:

[inaudible 00:45:50].

Stuart McGill:

Oh, the application of all of these things are just so interesting.

Whitney Lowe:

It's huge. Absolutely huge. Yeah.

Til Luchau:

It is.

Stuart McGill:

Oh, but posture doesn't matter, if you've heard that recently in some of the discussions.

Whitney Lowe:

Oh, yeah. Yeah, lots [inaudible 00:46:05]. Yeah, right. And I heard somebody make a tweak on that discussion that said, "Posture doesn't matter, except when it does." And, okay [inaudible 00:46:12]-

Stuart McGill:

Actually, I like that. I like that. If you have no pain, and we're talking sort of moderate human conditions here, that's fine. But when a person has pain and they have pain because of a certain posture, posture matters. I mean, there's lots of studies on that, by the way that's. That's easy to defend.

Whitney Lowe:

Sure.

Til Luchau:

And I've appreciated your descriptions of neutral as a range, as opposed to a certain position, say, where posture matters, with some give around that place where it matters.

Stuart McGill:

Yeah. That neutral zone, again, has been heavily discussed and misinterpreted by people who've never done the work, which that's another issue, who has influence in social media, I suppose. But the neutral zone isn't a number. It is a concept only, highly modulated by things like load. For example, you can measure the neutral zone of a muscle, but then compress the joint, suck it together. And all of a sudden, the neutral zone shrank. The breaking points and the neutral zone ... Well, theoretically, the stiffness of a joint increases with load. And if you keep putting load on it, theoretically, you could get to infinite stiffness. In other words, it doesn't move, and the neutral zone just went to zero. So when you say it's a range, you see there's a lot of moving parts, Til, that go into that, to have that discussion on, what's the neutral zone or neutral range here? It changes by the second, by the force, the joint position.

Stuart McGill:

It's so fun, when I would take our undergraduate students and I'd bring a student down in front of the class and we'd talk about, "How do you execute a jiu-jitsu arm bar on an opponent?" Because your job is to stress the joint to the point where the person taps out, gives up, they say, "I'm finished." Now, what did you do? You had to distract the joint and take away all controlling stiffness. In other words, you greatly increased the neutral zone and then put it into a very vulnerable position. When you're in that position, one degree or one millimeter of posture change is going to tear their shoulders, or at least cause so much pain that they give up. So Whitney, when you said "Posture doesn't matter until it does," if you can't get that, please come to jiu-jitsu class. You will understand very, very quickly.

Whitney Lowe:

Yeah, bit of a background many years ago in martial arts. I'm quite psychosomatically familiar with that concept.

Stuart McGill:

Yeah, right. Yeah, so posture ... What is jiu-jitsu? It's posture, and playing with that stress, pain, and neutral position or range, et cetera.

Whitney Lowe:

Yeah. One other thing I'd really love to hear your take on here, in looking at a lot of the orthopedic literature around back pain, it seems like there's a lot of focus on some of those core structural elements, the vertebra, the discs, the facet joints, and those types of things. And in our world, the people who are most of our listeners, are mostly soft tissue manual therapists. And I'd like to hear your sort of take on, what do you think is the most valuable and beneficial aspects of the approaches to our work in dealing with a lot of these kinds of back pain complaints, mainly soft tissue manipulation?

Stuart McGill:

Right. I have so many opinions, not all of it I can base on an experiment that we've done. We've done some investigations of chiropractic manipulation, as you may or may not know. But I'm going to promote this, I guess. If a clinician read our textbook for clinicians, Low Back Disorders, I've really described the assessment to probe pain in there, and how what you do can play a role. Let me give you some examples. I work in some very high performance sports circles. I don't know of a world class sprinter who doesn't travel with a mechanical manual tissue therapist. They are so close to breaking and tearing their hamstrings, so many parts of their system. People don't realize the stress of a hundred meters at full out effort. They have no clue, never in their life have they had to survive 100% effort. They don't know what is required. Those athletes do. And without the tuning of their tissues by that manual therapist, they will not reach speed, nor have the resilience to compete at that level.

Stuart McGill:

So, there's my first thought on that. I had a double sport Olympian, two very different sports, although they were both power strength sports. This athlete came with back pain sufficient that they couldn't train. It was predominantly the way that they were training, the exercises that they were doing, the volume that they were doing, that was causing their back to be so angry that they couldn't withstand the stresses of the sport. So we figured that out with assessment, and we gave them a new training program, and we alleviated all of that. But in the end, there was a little snag. It happened to be in one of the quadratus lumborum muscles. It just wouldn't let go.

Stuart McGill:

I don't have manual skills, so I build up my colleagues who have these skills. We form a team. And I said to the athlete, "I've done all I can for you. You're load resilient. But would you go see this clinician?" And within three treatments, that snag was gone, unleashed them, and back to the Olympics. So, I can give example after example. In my own life, I broke my hip as a youngster, and it went arthritic prematurely. And my whole adult life, I walked with a limp, until I had a hip replacement. Now, I look and feel fabulous, at least when I walk. But my point was, I was 45 when the surgeon said, "You're you're ready for replacement."

Stuart McGill:

Well, I had a colleague, you may know of him, Dr. Clayton Skaggs in St. Louis. He's the medical director of the Central Institute for Human Performance. And Clay would say, "Oh, let me have a look at that hip." And he would work his magic with his hands on ... not giving me a massage unspecifically, a general massage, because that would hurt my hip. I would go get massages, and I couldn't sleep at night, my hip was so relaxed and loose. It just ached and ached. Instead, he very strategically released some structures, facilitated others. And he would work through my first rib and whatnot.

Stuart McGill:

And here's me, talking as a scientist, I cannot explain what he did, but you would feel the difference. And again, Whitney, you won't believe this, but that effect would last weeks and weeks and weeks. I had my hip replaced when I was 57. And I credit those 12 years to Dr. Skaggs. I saw him every three or four months. I'd travel to St. Louis from Canada, because of all the clinicians, too, I would meet at conferences and they'd say, "Oh, well, let me play with that." And they'd hurt me, whereas he just had the gift. And I don't know if Barrence Baytos in Los Angeles, who has a client list of just superstars who come and see him? Or do you know Ann Frederick? She wrote the book, Stretch to Win.

Whitney Lowe:

I do.

Stuart McGill:

Yeah. And a couple of times she worked on me, and we ended up laughing. I said, "You used to make love to my hip, or you romanced my hip." And that poor woman would hold my leg for 20 minutes, and we would talk about things very quietly. And then she would start to work it. My God, 20 minutes. But what she was doing, she was preparing my neurology, not my biomechanics, I don't think, it was my neurology, to receive what she was going to do. And remember, by this time, I had a very heavy limp. I would walk out of the clinic without a limp. So, anyway, it's a bit of a personal experience, but there's some thoughts. Now, what did each one of them do? Stu McGill can't explain the high science of what each one of them did. It doesn't mean that they didn't do anything and nothing matters. They did a hell of a lot. [inaudible 00:56:08]-

Til Luchau:

Yeah. There's so much there in your stories. I mean, there's so many more questions. We'd have to order another round of those beer and peanuts to get in them, but that's almost an amazing place to look at our off-ramp here. That is such a poignant set of examples, and an acknowledgement that there's so much more going on than any of us understand. What do you think, Whitney? Anything else we want to [inaudible 00:56:30]?

Whitney Lowe:

Well, yeah, I think just as a teaser, a curious thing, Stu, maybe if you can just mention briefly what you are going to be talking about at the Fascia Research Congress? And Til, I think you had something else you were going to ask too, didn't you?

Til Luchau:

Yeah. I just wanted to mention your belly dance research. Where does that figure in to all these things? This is a study of accomplished belly dancers. And as I understood it, they didn't have pain.

Stuart McGill:

No, that puzzled me before I started the study. And as I said, I was looking and studying injury clusters, mechanical and psychological stressors and all the rest of it. And then one of my graduate students joined this belly dance group. And she said to me, "Stu, we don't know anything about these women. They don't seem to have any back pain. Let's go and measure what is going on." So, we took a scientific fishing trip. And it's true. They had the most extraordinary motor control. They could shimmy their hips from side to side and keep their ribcage statically still, and do the opposite, and create these reptilian waves in their spine. Whereas I can give you flex and extension, I don't think I can give you a reptilian wave through the spine. That's quite a gift.

Til Luchau:

Yes.

Stuart McGill:

But here's the thing, and it was one of the common themes that I kept converging on throughout my life. You cannot have it all. There's always a cost to a particular ability. The more mobility and fine control they had, it was at the expense of strength. I wouldn't ask one of them to lift a heavy load. Their spines were too supple. You need to have an I-beam in your spine if you're going to deadlift 1,000.

Whitney Lowe:

You're not going to ask them to run a chainsaw to help you clear branches, or something like that?

Stuart McGill:

No, I'm not. No. Yeah. Oh, you do know me. Yeah. Anyway, not one of them could do a competent sit-up, so they didn't have the strength to do a competent sit-up. Again, reinforcing the point, the wonderful mobility they had came at the trade-off of strength. So most people want to be somewhat middling between a lot of strength, a lot of mobility, et cetera. And that's when we start getting into using the word sufficient: do you have sufficient strength, sufficient stiffness, sufficient compliance, sufficient mobility, et cetera? Now, we can tune and adapt your body towards one of those, realizing that you're going to give up on some of the others.

Whitney Lowe:

Yeah. I think that was illustrated so well, I think, in some of the introductory comments in your back mechanic book, talking about people saying like, "Oh, you should go to Pilates or yoga because you have back pain," or something like that. And for certain individuals, that's just absolutely not the thing they should be doing, just because their physiology and mechanics are different.

Stuart McGill:

Right. There's a wonderful series of books written by a Yogi who I ... Well, he practices and follows our science very well. His name is Bernie Clark. And I think the books are Your Yoga, Your Spine; Your Yoga, Your Shoulder; Your Yoga, Your Back, et cetera. But it very much guides people through self-assessments of their joint anatomy and whatnot, and why some asanas or postures hurt them, that might be beneficial to others, et cetera. But everything comes at a cost.

Til Luchau:

Thank you, Stu. What are you going to talk about this year at the Montreal Fascia Research Congress?

Stuart McGill:

Well, I've been retired from the university for seven years now. And for the past three or four years, Mark Driscoll, one my professors who's organizing this, has been after me to come and do a talk. And every year I've said, "Mark, I haven't done the work for the past seven years. I really have trouble remembering references. I can't even remember my own studies."

Stuart McGill:

And he said, "Oh, just" ...

Stuart McGill:

And the day I left the university, this might strike you as strange, I said to all the graduate students, "Come to my office." And I had three walls of books. "Come and take them. Here are all my research papers, come and take those." And I said to all the professors, "Here's several million dollars worth of instruments and stuff. I'm just walking away. There it is."I never thought anyone would ever ask me to do anything again. I thought I'd be sawing my next year's winter wood supply. Anyway, I was wrong. So, Mark has asked me ... I said, "Mark, I don't have slides and data anymore." Excuse me.

Stuart McGill:

So what I can tell is a little bit of a story of my journey, where I started, as a graduate student 40 years ago, peeling the fascia off and throwing it away, and trying to understand how muscles and this linkage worked, and how my calculations never quite worked. I would take, say, an anesthetized rat. I would leave the left side of their belly muscles, external oblique, internal oblique, transverse abdominis, all intact, in Ringer's solution. And I would stimulate them and create a contraction and measure stiffness, measure force. But on the other side, I would separate the layers into their three constituent layers. In other words, I'd digest the fascia. And then, what a difference in performance.

Stuart McGill:

I used to think about muscles being agonists and antagonists, but I came to realize that, through fascia, the muscles are one. They form a mechanical composite. There are no agonists and antagonists anymore. They're all agonists, through this mechanical composite of fascia. So, that's where I ended up. And when I retired, I had such difficulty teaching biomechanics to first year students because the curriculum is, "This muscle creates flexion," and all this sort of stuff, when it doesn't.

Stuart McGill:

You get out of a chair, the hamstrings are active, the quadriceps are active, the psoas is active, the gluteals are active. They're all agonists to this grand scheme of creating sufficient stability, proximal stiffness, and then creating a net joint torque. But the redundancy, you can create that through so many different combinations. And then, let's cut one of the muscles. The system still works, because of the fascia creating this wonderful redundant composite. So that's the end of my lecture, but it's the story of how my brain got there. I don't know if this is going to be of interest to anybody or not, but-

Til Luchau:

No, that's fantastic.

Whitney Lowe:

Oh, I think you'll find a great deal of interest. Yeah.

Til Luchau:

That's right. And there's got to be some lessons in that for the world. We'll leave that aside for now, but something about that there are no agonists, antagonists. They're all agonists, somehow. There's got to be something in there. How can people find out more about your work and what you do?

Stuart McGill:

Well, we have a website called backfitpro.com. And if you're a clinician, there's one portal of entry. And we've got all the resources, books and courses and that sort of thing, for interested people. And if you're a back pained person, we have another portal. And it describes there is a reason for your pain, and here are some of the steps. So when I wrote Back Mechanic, it starts out as guiding the reader through a self-assessment of their pain. So for the first time they realize why, when they roll over in bed, they get a sharp pain, or why, when they sit at the computer for 20 minutes, they get back pain, and then go for a walk for 20 minutes, it takes the pain away, or vice versa. They sit down and their pain goes away, and they go for a walk ... It helps guide them, and then gives them strategies to wind down the pain and then build up a pain-free resilience for getting through life. Anyway, that's [inaudible 01:05:20]-

Til Luchau:

What's that one? What's that website? First one's BackFitPro, the second one ...

Stuart McGill:

It's all on BackFitPro.

Til Luchau:

It's all on BackFitPro. Okay.

Stuart McGill:

Dot community, yeah. But the first book for people, le public, with back pain, is Back Mechanic.

Til Luchau:

Back Mechanic.

Stuart McGill:

But the book for clinicians to learn how to do a very thorough assessment to converge on a precise understanding of why this person has pain, that's called Low Back Disorders. And then once a person has gained resilience to do everyday things, but they want to get back to swimming or cycling or deadlifting or whatever it is, that book is called Ultimate Back Fitness and Performance. So each book has a little bit of a different contribution, I suppose, depending on who the reader is.

Til Luchau:

Thank you. We'll put all those into the show notes.

Whitney Lowe:

Yeah. And on behalf of the world of people in pain, I would just like to say a humongous thank you for all of your many years of work and dedication to this. And you certainly have been an inspiration to me and lots of other people for all of the wonderful things that you've contributed. So again, it's quite an honor to have you with us here today. And thanks again so much for your time and your contributions.

Stuart McGill:

Well, thank you so much for having me, Whitney and Til. And I guess, Til, I'm going to meet you in Montreal.

Til Luchau:

I look forward to that.

Stuart McGill:

And Whitney, until we meet again, stay well and resilient.

Whitney Lowe:

All right, that sounds good.

Til Luchau:

Nice.

Whitney Lowe:

Good. And do you remember Books of Discovery? It has been a part of massage therapy education for over 20 years. Thousands of schools around the world teach with their textbooks, e-textbooks, and digital resources. In these trying times, this beloved publisher is dedicated to helping educators with online-friendly digital resources that make instruction easier and more effective in the classroom, or virtually. Books of Discovery likes to say, "Learning adventures start here," and they see that same spirit here on The Thinking Practitioner Podcast. And they're proud to support our work, knowing we share the mission to bring the massage and body work community enlivening content that advances our profession.

Til Luchau:

Check out their collection of e-textbooks and digital learning resources for pathology, kinesiology, anatomy and physiology, at booksofdiscovery.com, where Thinking Practitioner listeners save 15% by entering "Thinking" at checkout.

Whitney Lowe:

And we would like to say a thank-you to all of our listeners and to all of our sponsors. You can stop by our sites for show notes, transcripts and extras. That is over on my site at academyofclinicalmassage.com. And Til, where can they find that with you?

Til Luchau:

My site is advanced-trainings.com. We should also mention the Fascia Research Congress or Fascia Research Society is a special sponsor of today's episode. Go ahead, check out information about their conference at fasciaresearchsociety.org. Look for us on social media at our names, @tilluchau, or-

Whitney Lowe:

WhitneyLowe, that'll be my name today. You can rate us on Apple Podcast, as it does help other people find the show. And you can hear us on Spotify, Stitcher, Google Podcast, or wherever else you happen to listen. So please share the word. Do tell a friend. And thank again so much for dropping by and listening with us today.