Jared Powell:
Today's guest is Amy McDevitt. Amy is an associate professor at the University of Colorado and practices clinically at the University of Colorado Health and CU Sports Physical Therapy and Rehabilitation. Amy is an entry-level educator and is actively engaged in clinical and educational research. Amy has a particular interest in unraveling the mechanisms of manual therapy. In other words, Amy and her collaborators are trying to ascertain how and why the application of a manual therapy technique for a particular musculoskeletal condition causes a particular outcome such as reduced pain. This goes beyond asking, is manual therapy effective, but seeks to explain how and why it is effective if indeed it is. Amy brings the explanation of manual therapy into the 21st century with a plum, encourages us to move away from antiquated notions of manual therapy and communicates why mechanistic research is necessary for clinical progress in musculoskeletal pain. Without any further delay, I bring to you my conversation with Amy McDevitt. Amy McDevitt, welcome to the show.
Amy McDevitt:
Thank you so much for having me. I'm excited to dialogue with you this evening for me, this morning for you.
Jared Powell:
Yeah. You are over in the, you're over in the us Whereabouts are you based specifically in the us
Amy McDevitt:
I'm in Denver, Colorado. Beautiful.
Jared Powell:
So
Amy McDevitt:
If you wanted exact longitude and latitude, I don't know it at the top of my head, but yeah, we're in we're just finishing up winter, heading into spring, but so not originally from here, but I've been here 25 years, so I think I'm a, I'm a resident.
Jared Powell:
Yeah. Cool. It looks like a stunning area when you see all those mountain ranges and everything. It looks, it looks beautiful. Is it nice to live there? Yeah.
Amy McDevitt:
Yeah, it's great. Yeah. I think coming from the Midwest in the United States, which is kind of flat and cloudy, I think it's a nice respite. I think we take advantage of it fully. Mm-Hmm. We spend a lot of time in the mountains. We, meaning my, I have three kids so we recreate up there a lot, and so I don't just look at it on my commute and I actually go up there once in a while and I enjoy it. ,
Jared Powell:
You actually get in there. That's, that's how it should be. So this might lead into the next question. So what do you like to do for fun, Amy? And then also what's your professional role?
Amy McDevitt:
Okay. what do I like to do for fun? I think, as you probably know, it evolves over time, but currently I I love to read. I'm kind of a World War II history buff. I have no idea why, but that's interesting to me. I love to travel. We, my family, we travel quite a bit. I do a lot of cycling and hiking and, and skiing. And most of my adult life I played ultimate Frisbee. I don't know if you see a lot of that in Australia, but definitely.
Jared Powell:
Yep. Yep.
Amy McDevitt:
Played competitive co-ed, ultimate Frisbee. So that was a big part of my life. And now that I have a couple kids and a couple dogs, I'm doing different things, so, yeah.
Jared Powell:
Awesome. And so the environment of, of Colorado lends itself to all those activities that you mentioned pretty well, I imagine.
Amy McDevitt:
Yeah. So, you know, the biggest conundrum, I think people that live here face is on Fridays. Everyone wants to head up to the mountains, and so there's this mass exodus of all the city rivers. So we usually sit in traffic for anywhere from three to five hours to get somewhere that's only 60 miles away. Wow. But it's still worth it.
Jared Powell:
Absolutely, yeah. To get that fresh alpine air. Okay. Cool. And then professionally, what are you up to these days?
Amy McDevitt:
What am I up to? So I work at the University of Colorado, which is in it's in, it's in Denver, but we have a really large medical campus that's just east of Denver. So we have seven programs on my campus. So I'm, I feel really lucky to work here. We have school of medicine and dentistry, pharmacology, nursing lots of things going on. So it's a thriving R one institution. So there's a couple hospitals on our campus, including a veteran's hospital, children's hospital. Anyway, so I've been on this campus about 10 years. So I was in clinical practice for like 10, 12 years, and then kind of shifted over into academia, and so now I teach in the orthopedic based courses, and then I, I treat patients once a week in the hospital outpatient center and do some research in addition to that. So it's good.
Jared Powell:
Cool. Yeah, that's, it sounds like a varied role. Will you maintain a, a clinician aspect to your role, do you think, going forward? Is that important to you?
Amy McDevitt:
Yeah, I, I do. I mean, I think, I think inherently that's who I am, and I think everything that developed out of that came from my experience in clinical practice, and I continue to value it. I think if I'm gonna teach in orthopedics, I need to know what's going on. And so I treat patients every week and, and I, and I love it. I, I don't think it would be easy for me to give that that piece up. Yeah,
Jared Powell:
No, I agree. I often find a lot of the ideas that I have for resource research are born out of the clinical interaction, you know, and I think I'd struggle if I lost that, but I can understand people are pulled in many different directions, but I think combining a clinician and research role is, is really important.
Amy McDevitt:
Yeah, I agree. And I think you and I would both probably agree that things evolve, you know, now I, I think about person-centered care, I think about social determinants of health, you know, things that we weren't necessarily talking about as much 10 or 15 years ago. And I think how we practice evolves every couple years based on some of the things that we're seeing more prevalent in the research. So I think it's important to, for that to be palpable for me.
Jared Powell:
Yeah, for sure. I think we'll tease that out a bit, a bit later in our conversation. So, so the topic of our, our chat today, Amy, is manual therapy. And we're gonna, before everybody, you know, gets the popcorn out and and gets and looks forward to a controversial conversation, it's, we're gonna take a little bit of a different approach. So instead of asking whether manual therapy works and comparing it to no treatment or exercise or any other usual care type of comparator or even a placebo comparator, we're gonna, we're gonna move away from that. And we're gonna, we're gonna explore the question, how does manual therapy work, which, and you've published a really cool paper, sort of adjacent to that topic recently, which I'll, which I'll link to in the show. So we're gonna be talking a lot about mechanisms. And so before we start saying mechanisms, every sentence for the next hour, what is a mechanism?
Amy McDevitt:
Yeah, fair question. I think it's important to define that before we go further. It's, if we take it down to its more basic definition, it's the steps or processes through which an intervention produces a change in an outcome. So it's, I think it's important to also probably define what a specific mechanism is and a shared mechanism. Do, if you don't, if you don't mind me going there now. Absolutely. I think it's kind of part of that broader context. So the specific mechanisms are really probably more about these unique features of an intervention that are considered maybe the primary reason that it's effective. I think two probably prime examples that you and I are both familiar with would be manual therapy and, and exercise. So each of those are interventions that we use in clinical practice, but both of them have probably specific steps or processes through which those interventions, you know, really change, change in outcome.
Amy McDevitt:
If we think about manual therapy, I think that we know that techniques and manual therapy may produce both peripheral central mechanisms and influences. If we think about something like exercise, we might talk about seeing changes in maybe muscle fiber size or neural adaptation. So those are examples of mechanisms that might be at play with, with two different interventions. So then if we use or define this example of, of shared mechanisms, those are what we're calling more or less non-specific. So that's taking two seemingly different treatments such as, you know, monotherapy and exercise with seemingly different mechanisms. And those are found to maybe exert their effects on clinical outcomes via some common mechanism. And so when we're talking about things like shared mechanisms, we're talking about about things like, you know, therapeutic alliance, the environment, contextual factors, quality of the relationship with the provider. So those are kind of things that we're calling shared that, you know, if you are the, the clinician that's doing something in terms of exercise, and I'm doing something in terms of manual therapy, those things both specifically have, have specific mechanisms, but then the shared piece is just our relationship with our patient and all those other things that are occurring in the context of clinical care.
Jared Powell:
Beautiful. Well, well said. So just, just as a recap, so mechanisms, steps, processes that kind of underpin perhaps Mm-Hmm. a treatment that causally leads to an outcome. And that's important. It's a causal mechanism. I kind of understand a, a causal mechanism or, or how I, how I model it in my head. It's, it's basically what's the causal explanation for how this phenomena came about? And I find that's a nice easy way to think about it. And then a specific mechanism is it maybe has a unique mechanism particular to that treatment. And then a shared me mechanism is two different treatments that look entirely different on the face, but underneath they, they share some common ground in terms of mechanisms. Is that a, is that an accurate summary there, Amy? Yeah,
Amy McDevitt:
I, I think that's a great summary. And I think the other thing to consider is that in each of those intervention examples, so manual therapy exercise, we're not talking about just one mechanism at play. We're talking about multiple mechanisms that are probably occurring for each of those interventions that can also be a little bit diffi difficult to untangle . So yeah.
Jared Powell:
Yeah, disentangling mechanisms is a huge job. And if you want to venture into the literature on talk, talking to the listeners here and start studying mechanisms good luck. Give it a, give it a few years. That's right. It's a, it's a hard, it's a hard graft as, as you well know, Amy.
Amy McDevitt:
Yeah.
Jared Powell:
So why, why do we study mechanisms? What's the point? Why do we need to know how treatments work when they're showing two work? Why don't we just get on and start treating the person when, when we, when we see these small to modest effect sizes in, in clinical trials? Yeah.
Amy McDevitt:
You know, I think that's the million dollar question, right? You know, why do we care and why are we putting time and effort and energy into it? I think, I think the clinical effectiveness research has really gotten us a long way, right? And helping us to determine, you know, manual therapy has value, exercise has value, combination of those interventions has value. But I think as we kind of move closer to trying to cater care and really trying to kind of appreciate precision medicine, which is just, it's trying to cater care and provide more personalized care. And I think in order to do that, there's a couple things that need to happen. One is we, we do need to understand the mechanisms that are at play with these different interventions, whether they're specific or shared. I think an understanding of that will help us to cater care better, because not everyone needs the care we're providing.
Amy McDevitt:
I think, and I might talk about this again later, but I think clinical practice guidelines have done a really nice job of getting us, you know, to where we are now and saying, these are the recommendations that we think are best for people with, you know, fill in the blank, maybe health condition or, or fill in the blank musculoskeletal pain. But it's still is a one size, it's still a one size fits all approach. And I think we're interested in moving the needle a little bit further in being more precise in being able to determine what is best for each of our individual patients and, and not just, you know, tossing everything, manual therapy, exercise, education, behavioral therapy, things like that at everyone in, in the hopes that we're gonna get the outcomes that we're looking for.
Jared Powell:
Yeah. I guess a bit of a, a vulgar phrase comes to mind, throwing at a wall and hoping something sticks. That's it. Right? It's, it's, so you, so you mentioned precision medicine there, and so do you mind just giving me or the listeners a a brief summary of what precision medicine means in this context?
Amy McDevitt:
Yeah. I think in this context, precision medicine is really taking medical care and really designing it for particular groups of patients or for individuals instead of just saying, we're like, you said, we're gonna take all of this and just throw it at anyone with back pain. Again, I think we've, we've improved a lot over time, especially with clinical practice guidelines, providing more guidance and, and trying to also give us a little bit more information about how to subgroup patients. But I think we still have a long way to go. And I think if we're really gonna tout that as physical therapists, we provide personalized care we have to be precise. And I think precision medicine is really trying to target those specific interventions to the specific health, health conditions that we encounter. It's happening in other areas of medicine, but in physical therapy, we're not there. I think there's a lot of information still let to yet to learn.
Jared Powell:
Totally. Yeah. We're, we're a young-ish profession when it comes to evidence-based medicine, right. And we're kind of, and Chad Cook says this, we're, oh, what does he say? I think he says, we were building the plane. No, while we're flying, we were learning to fly the plane while we're still building it or something like that.
Amy McDevitt:
Building it while we're flying it, building it while we're
Jared Powell:
Flying. It's, right. Yeah. Good. And that, that always resonates with me when I think about it, because I, I inherently, I'm a big fan of criticism and, you know, error correction and progress and getting better and doing all of that. And I think it's crucial as, as a, as a, a key tenet of science. But then when I, sometimes I get, I get a little bit overwhelmed with all the criticism and the poor quality research that's out there and everything, and then I, I come back and go, it's all right. You know, we're, we're trying to do all of this on the run. We're getting better slowly, we're recognizing where, where the flaws are, and we're hoping to change that over time.
Amy McDevitt:
Yeah, I agree. I mean, I think it's really the only direction to go because there has been a lot of great and, and intentional and focused and meaningful work that's been done in terms of trying to determine if interventions are helpful, but it is time to figure out why, you know, I think we're gonna get better at what we do if, if we know why the interventions that we're employing are effective, and maybe we come to find out that there's certain interventions that we shouldn't be, you know, applying towards certain individuals or populations. So yeah, I think it's all in an effort to optimize care.
Jared Powell:
Yeah, absolutely. Opt, opt, optimize, and make more efficient. I think that's the key. And how I think about the value of studying mechanisms is that you're removing the fat, you're removing the fluff, the stuff that doesn't really causally isn't causally responsible in any way for, for an outcome. Yeah. And having, I've got a big interest in resistance training and, and that, and the role of that in reducing pain in shoulder pain. And we used to think that strength is the intermediate variable that you need to change and, and target. And it's looking like it's not really the case based on the available evidence that we have now. And that applies to osteoarthritis as well, where strength only mediates 2% of the outcome of knee and hip osteoarthritis. So 98% of the treatment effect of exercise for OA remains unexplained. So it, it's really, so the study of mechanisms there has helped us reframe what, how our interventions work and what is a plausible treatment target that we need to identify in clinic. Can we change it? And if we can, does it change the outcome?
Amy McDevitt:
Yeah. And to your point, you know, in terms of things like exercises and intervention and, and resistance, I think having a little bit of a better understanding of mechanisms will also afford us the opportunity to understand dosing. You know, I remember in one of your it was your viewpoint and you did a really nice, kind of unpacking that with multiple reflection points on your podcast, which I really enjoyed. But I think you brought up a really interesting point, which is, we still don't know what optimal loading is, and, and optimal intensity and dosing, and hopefully having a, a better understanding of mechanisms will solve a little bit of that conundrum too, which is how do we dose manual therapy? How do we dose exercise? How do we dose them in combination? Yeah. Because I still think we're doing what we know we should do from best evidence, but a lot of times it comes in the form of using the alfredson protocol in terms of, you know, treating tendinopathy or in terms of manual therapy using the same seven techniques that have been replicated across multiple studies, just because that's the treatment package that was utilized.
Amy McDevitt:
Yeah. Which isn't, you know, it doesn't feel right all the time, but that's what we know at this point.
Jared Powell:
Yeah, no, I'm, so with you there, like, what person needs a high dose of exercise? What person needs a low dose of exercise? Same thing with manual therapy. Again, coming back to precision medicine. So let, let's go to, let's go to manual therapy.
Amy McDevitt:
Okay.
Amy McDevitt:
Yeah, I think that question in itself is opening up a huge can of worms, because it depends on who you talk to . So, okay. If you look at definitions from, you know, the A PTA or, or I os the International Federation of Orthopedic Manual Physical Therapists, or if you look at the NIH definition or the, the ICD 10 code, you know, the, I'm sorry, the billing code that we use there, there's a whole plethora of things that'll fall under the definition of manual therapy. And some would say it, it distills down to providing a mechanical force. And so maybe it's thrust, maybe it's non-trust, it's soft tissue, maybe it's neuro mobilization. There's debate about whether or not dry needling fits into that category in terms of manual therapy. But I think if we really distill it down, it's, it's producing some kind of a mechanical stimulus or an input. And I think there's a whole list of things that you and I could both take turns naming off, and that would take our entire hour to talk about all the things that probably fit into the category of manual therapy. But, and I think that's another that needs to be solved. 'cause I think that also creates problems. You know, the heterogeneity and the definition alone creates a lot of problems in trying to describe it.
Jared Powell:
Yeah. I'm with you. I saw that Jason Silverdale has just published a paper trying to update the definition in PTJ. I haven't read it. I'll, I'll link the paper in the show notes, though. We, let's not get too derailed with definitions because semantics and linguistics is a nightmare. Yeah. So, but
Amy McDevitt:
That's your fault. You asked me to define it.
Jared Powell:
I, no, I know. I apologize. ,
Amy McDevitt:
I just jumped on that rabbit
Jared Powell:
Hole. That's, I'm gonna bring it up and then I'm gonna blame you for talking about it. That's, that's, that's how good strategy so manual therapy, how does it work? Do we have an idea? Are there any proven mechanisms first and foremost, or are they all theoretical or hypothetical at this point? Let's start with the old classic biomechanical viewpoints in terms of blood flow, adhesions. Yeah. All of these kinds of things. Yeah,
Amy McDevitt:
I think, I mean, that's where I started from, at least in my own education. I think, you know, originally it was about peripheral mechanical mechanisms. And so, you know, I don't, I don't know when you had, you know, when you received your education. I went to physical therapy school in 1998. I graduated in 2000 in the us it was a master's degree. And then later, you know, I did a transitional degree. But back at that time, in 1998, 2000, we were still very much sold on the fact that this was a peripheral mechanical issue that involved positional faults. It involved adhesions, it, it involved the facet capsule and even down to a certain size and a certain direction, all that stuff. So I think we've, we've started to kind of move away from that, thankfully, from, from I think some of those more antiquated frameworks.
Amy McDevitt:
When I think of like contemporary manual therapy in terms of mechanisms and, and hypotheses about what's happening. I really gravitate towards the BISKY framework. Yeah. You know, I, I think hopefully listeners are, are familiar with, but I think that's a, a great model. I think some of it was hypothesis driven, and now a lot of it, a lot of it has been confirmed in, in animal models. So I think the animal studies and the animal models have really given us a lot of information about what's happening physiological in terms of mechanisms. But I think there's still a lot of bench research and cage research that's continuing to try to sort out what exactly is happening at a physiological level. I think one of the limitations with, with animal models is it's given us a lot of information about what is happening from a mechanism standpoint, but it doesn't always transfer to the humans, to the patients in front of us. And so that's one of the limitations of just taking everything from, from, from the animal studies. I think they've gotten us a, a long way, but I think looking at this in, in humans is a little bit different
Jared Powell:
For sure. Yeah. It's a, it's a, it's a good basic science starting point looking at looking at this stuff in animals, but you've got to generalize it to, to homo sapiens at some point. You mentioned baki that his work is, is seminal. I think I remember reading his paper 2009, 2010, and I followed his work a lot since then. Yeah. And he ki he kind of emphasizes the neurophysiological aspects in terms of the peripheral nervous system, the central nervous system, and then the supraspinal. So the, and then there's psychological stuff as well, and, and the, and the clinical context is, is key. Yeah. In his model as well. I, I skimmed one of his papers yesterday just reflecting and preparing for today. And I reread his paper on the, on the placebo aspect of manual therapy. I think it was A-J-O-S-P-T view viewpoint a number of years ago.
Jared Powell:
And he, and he emphasizes that you, part of manual therapy is the contextual effects that are associated with it. Mm-Hmm. . And it's perceived as being a bad thing generally. Like if you look out there in, in the world of social media that, you know, contextual effects are bad and placebo effects are bad, but you, not bad. But because they're not specific effects or mechanisms of a treatment, they're, they're denigrated or, or looked down upon. But you can't, these are all things that influence an outcome. So why do we denigrate these concepts like the therapeutic relationship, like the, the ritual and the ceremony of, of imparting manual therapy to someone when they can really help someone have a better outcome, which can get them back to a meaningful activity. Do you have thoughts and opinions on that?
Amy McDevitt:
I do. I think, and, and one thing I guess I would say about their framework, their updated framework is that's where they really, I believe, dove into those contextual factors a little bit more. And really try to describe, you know, I can almost picture the framework in my head, 'cause now they have it like divided into zones, but this relationship or this contextual piece, meaning that interplay between the therapist and the patient, i is a big factor that obviously is contributing to outcomes. And I think my perspective is we need to figure out a little bit more about the power of that piece, because a, that piece might be more important than specific mechanisms that we were already talking about, you know, not physiological, peripheral central. But I also think the contextual factors might amplify the specific mechanisms. But, you know, I think there's still so much to, I don't know if I'm making sense, but I think in some health conditions, the contextual factors might be more important than others. I think across the board, we don't know the power of those contextual factors, and we might come to find out that maybe in terms of how we manage patients and how we teach future therapists, maybe we need to focus more on tapping into the contextual factors if we find that those are just as important or more important in driving some of our patient outcomes.
Jared Powell:
Yeah. No, i, I dunno how
Amy McDevitt:
Important they really are.
Jared Powell:
Yeah, I totally agree. And you mentioned that maybe the contextual mechanisms or factors could amplify the other mechanisms. And I, I totally agree with that. I'll take that a step further and say that having that clinical context is, is fundamental or foundational into activating the mechanisms in the first place. So if you have a poor or strained therapeutic relationship, I reckon that is enough to inhibit the activation of the mechanisms of the treatment, because that person is gonna have, and and this is a, this was the outcome of a study that I just published, a qualitative work, which found that exercise doesn't work in the absence of a strong therapeutic relationship. You know, so, and, and this comes back to a dispositional approach to causation, where, you know, causation is context specific and context dependent. So if you don't establish a solid relationship with the patient that you're working with, then really no matter what you do generally in gray areas such as musculoskeletal pain, yeah. It's not gonna work. You know, it's not just like we can throw an antibiotic at an infection and it's gonna help them no matter what. It's, it's far different when it comes to the murky areas of pain.
Amy McDevitt:
Right. And I think we can't say that about every domain of medical care, but I think when we're talking about things like psychology, when we're talking about things like physical therapy, where that relationship and the alliance and all of that is baked in to, you know, the interventions and, and the care, I don't know that we can really appreciate fully the power of it, which is why I think many of us are interested in exploring this mechanisms conundrum, because it's not just about specific mechanisms of a minutia intervention, it's, it's shared mechanisms too, which really speak to these contextual pieces that you're asking about.
Jared Powell:
Yeah, for sure. So, so are we happy to say that blood flow adhesions, mobilizing specific joints, you know, facet joint cap size, individual segmental mobility, or all of these kinds of things that we were indoctrinated and taught a long time ago, are we, are we happy to say they are antiquated and perhaps refuted as a, as a mechanism of manual therapy?
Amy McDevitt:
I mean, I hope so. I think, though I still wanna be respectful of some of the, you know, foundational work that was put into developing manual therapy, you know, as an intervention. I think it was very much mechanisms related to biomechanics and local faults when it, when it first developed. And so I think it's evolved over time. But I would like to say with confidence that I hope we're dismissing more of these, you know, local mechanical mechanisms as being the main players. And I think with that being said, we're also saying that examination strategies should have also evolved too, right? Because if we're saying that, that the intervention is based on local mechanics that are happening, let's say in the spine, then I think we also need to move away from examinations that are exhaustive in nature, that try to sort out all these mechanical faults that are happening locally, you know, in the hopes that those are even contributing to patient deficits and function, you know? Mm-Hmm. That's the other piece too. So, wow. I really, I really took a long cir circular explanation to get to your answer, but I, I guess I'm saying, yeah, I think we're moving beyond that.
Jared Powell:
It's good. I'm enjoying the journey here, Amy. It's good. And yeah, obviously we do want to pay respect to, you know, research that has come before us and a hallmark of science is that we're, is, is, is critical examination and scrutinizing ideas, finding errors, error correction. Yeah. And then hoping, getting better in the future. So everything that we say today is not in the context of, oh my God, I can't believe that. We used to believe that. It's, yeah, that's what we used to believe. We're testing it now and, and we want to go forward.
Amy McDevitt:
You're right. And you and I will be those people someday, you know, and I hope we both have the humility Absolutely. To be able to be okay with work moving beyond what, what our contributions were. I think that's the whole point.
Jared Powell:
Yeah. Look, if, if Albert Einstein he said that he hopes that his theory of relativity will be replaced one day. So if he can be as intellectually humble as that with arguably the greatest theory that's ever existed, then surely our little theory is about manual therapy and exercise. We, we must be okay with that being replaced at some point.
Amy McDevitt:
Agree. Agree. Good,
Jared Powell:
Good. Okay. So, all right. We're happy with manual therapy ish when it comes to the fact that we might need to update our model of how it works. And we've mentioned the model of Joel Bofski there, which again, I'll mention in the show notes and people can go and read about it. It's fabulous. Yeah. He's got a, he's got a large body of work that I encourage everybody to read. So let's talk about shared mechanisms now. So if we have, let's say, manual therapy, and we have exercise, and we, we do a comparative trial, and we find that these two interventions produce very similar outcomes. Let's say it reduces pain by two points out of 10 or on a visual analog scale, and it improves function at a similar rate, but there's no significant difference between them. So how can that be, right? Because they've got two very different purported mechanisms of effect, and yet they produce a similar outcome. So what, what do we think is working under the hood of these mechanism of these treatments when it comes to shared mechanisms? Do we have any theories about that?
Amy McDevitt:
Yeah, I think there's some, there are some theories. And then of course, you know, that other piece is just natural history, right? So we would love to think our interventions are so amazing that everything has to do with the, the specific mechanisms behind those interventions, which I think is what we used to once think at least I did, I can't speak for, for other providers. I think in terms of shared mechanisms, a lot of what we're hypothesizing is coming from the psychology literature. So I think another article that I would recommend putting in the notes would be from Burns and Colleagues. It was, it was published in 2023, and it, and it looked at comparing different interventions used in psychology. So mindfulness based stress reduction cognitive behavioral therapy, and beha, another type of behavioral therapy. Anyway, each of those specific interventions has seemingly very different specific mechanisms.
Amy McDevitt:
But the result of that study was showing that actually the shared mechanisms that they captured were much more relevant than the specific mechanisms of each of these individual interventions. And so I think in pt, I think we're pulling a little bit from psychology and hypothesizing that some of those same shared mechanisms, so things like therapeutic alliance pain, self-efficacy, clinical equip pose, you know, I think therapists interpretation of, of the relationship are what I'm describing in terms of shared mechanisms. Although some would argue that it's, that it's bigger than that. There's a lot more to it than just those couple of pieces. But I think in terms of looking at how to study shared mechanisms from a research standpoint, those are some of the bigger players in terms of what we're talking about. And so, with that being said, I think there's, there's methodology that, that was used in, in that study by burns and colleagues that affords us a, a little bit of intel in terms of what methods we need to utilize in order to sort out some of these differences between, you know, what is mediating the outcomes, is it specific mechanisms or is it shared mechanisms?
Amy McDevitt:
So I hope that answers your question, but I think that's where I'm getting a little bit of my, my intel or information in terms of what are the shared mechanisms that we're, we're talking about.
Jared Powell:
Yeah, I've read that paper and a couple of others, as you said, in the sort of behavioral therapy psychological literature where it's like all these different types of therapies work via the same sort of similar psychological mechanisms of pain, self-efficacy, pain, catastrophizing, all of these kinds of things. Yeah. Yeah. We know that exercise, there's a little bit of work out there in non-specific low back pain. I think that exercise can improve pain, self-efficacy, so it can actually change this construct of pain, self-efficacy. Do we have any work in manual therapy world where manual therapy can increase pain, self-efficacy, or decreased pain catastrophizing or any of these purported mediators?
Amy McDevitt:
Yeah, you know, I'm not, I'm not as familiar, I'm not dialed in at the moment with knowledge about specific studies in terms of answering that question. But I think you know, I think potentially if we're talking about exercise and its ability to kind of change things like pain, self-efficacy, efficacy and fear, I think manual therapy we know has some of those similar, whether it's manual therapy or manual therapy com combined with exercise, I think we see some similar results just globally in the literature that there can be some changes in fear avoidance behaviors, pain, pain, self-efficacy. But I can't dial into our quote specific studies.
Jared Powell:
That's fine. I'll yeah, I'm asking a lot of you just apologies, but I, I just say things when they come to my mind. And another thing that's come to my mind is oh,
Amy McDevitt:
, I smell a rabbit hole.
Jared Powell:
. What if, if it, if it turns out, Amy, that we study the mechanisms of all these things, and the predominant mechanisms is the, the clinical ceremony and the expectations of the patient and the conditioning of the patient and all of these things, and there's a very small specific mechanistic component to a treatment. Any, this is any treatment. What do we do with that in a clinic? Are we happy sort of ethically or morally to just say that this is an elaborate contextual modifying procedure? You know, like we're gonna have to confront these questions, perhaps, and I, I think we should be ready for the answers that we get. What, what, what do you think? Or, or is that little, I think from the literature at the moment, the specific mechanism or the specific component of a treatment is still estimated to be about 30%, which is significant. You know, if you can change that 30%, that's gonna have a big difference on a clinical outcome. Do you have any thoughts about that? If that question makes sense? Yeah,
Amy McDevitt:
No, I think the question makes sense, but, and I think, I think if we're talking about either, like, I still like us coming back to the example of manual therapy or exercise. I think within manual therapy, we already described that there's a whole plethora of things that fall under that umbrella. But which of those are the golden ticket? And I don't, I wanna know which of which of those things are the golden ticket. You know, is it, is it the patient actively engaged with the mobilization? So some type of active mobilization while the patient is contributing to it? Is it soft tissue mobilization? Is it thrust manipulation? Which of those things is, you know, really the, the most important or the priority intervention that's gonna optimize the outcomes? Because I don't think any of us, whether we're talking about exercise or manual therapy, I don't think any of us want to utilize our time doing all of it, because we're not sure which ones matter the most.
Amy McDevitt:
So I, I guess that's my answer. But I also know that when you look at, for example, the framework by Biolaws and colleagues, there are so many mechanisms at play. I don't know that the goal is to necessarily narrow it down to a minutia mechanism that we can attach to a single technique. Because I think whether we're talking about exercise or whether we're talking about manual therapy, I think within each of those specific interventions, we're hypothesizing that there's multiple mechanisms that are probably at play. And so I don't know that we're ever gonna be able to dial into one specific thing, but I would like to think that at some point we're gonna get to the place where we can determine truly which, which interventions have the most power. It was Julie Fritz was in a, I think it was like a force net webinar, and she said something that I, I wrote down, so I have it written down over here.
Amy McDevitt:
But what she said that I thought was, was really important is she said, we need to disentangle contextual and real treatment effects. So we, we first need to kind of sort that out and we can't separate the components in the context of clinical care. And so I think what she meant by that is, you know, the, the needle is probably moving, but there's so much to sort out and to separate, which is why I think it's really important to, at least in the beginning, try to understand those differences between the power of shared and specific mechanisms. Because then I think we need, we know where we need to focus our attention. You know, do we need to focus our attention? And I, I think I said this before on the interventions themselves, or do we need to really focus our attention on those, you know, contextual factors that really might be important in driving some of the outcomes that we see?
Jared Powell:
Totally. And then,
Amy McDevitt:
Oh, what do you say?
Jared Powell:
Yeah, it's, well, yeah, good question. I think there's a lot of, it's all up in the air at the moment. We're, as you said, we've got so much work to do when it comes to researching this stuff. We are really in its infancy in terms of investigating causal mechanisms. So I'll be reluctant to put the cart before the horse and, and make all these grand statements as as you were too, because we can't be definitive about it. We just have to see whether, where the research takes us. Yeah. I would be, I would feel uncomfortable though, let's say in 10, 15, 20 years, hopefully I'm still working. Hopefully I'm I've still got the passion and you know, it comes out that all of our treatments are just a grand theatrical placebo with a very small, small specific mechanistic component. Mm-Hmm. I would feel a bit funny about that.
Jared Powell:
And I would wonder how, you know, how we would change our practice in order to incorporate that evidence. 'cause If we are to be an evidence-based profession, we're gonna have to, we're gonna have to adopt that evidence. So we're not there yet. And I, my my prediction is that the specific component of a treatment will be a significant component going forward, but it's just, we've gotta tease that out. And as you said, disentangle and partition that effect. And again, it's gonna be hard because there may actually be different mechanisms for different patients, right? So that's right. So like, you can take a 200 people and you get an average of your pain. Self-Efficacy is the, is the mechanism or mediator there, but it might be for one person, it might not be for the next person. The next person might need reassurance. The, the person after that might need some of that neurophysiological effect. The next person might need exercise where they feel like they're getting load through their shoulder or back, and that increases confidence, which changes their outcome. So talking of mechanisms at scale is different to talking of mechanisms individually.
Amy McDevitt:
Yeah. And that's why I think sometimes it seems like these debates, specifically when we're talking about manual therapy and exercise, seems so arbitrary because I think all of it matters. And we, we can't even sort out what matters the most. And, you know, so I think some of the debate between what's better and what's, what has efficacy and what does doesn't, I, I think is sometimes a little bit ridiculous because we, we haven't, we haven't really sorted out. We, we understand from I think, effectiveness research that we can appreciate globally what interventions we should be utilizing, but we don't really know why , you know?
Jared Powell:
Yeah. Yeah. We're back to the why, the how and the why again, which is the whole purpose of today's chat. I like how we keep coming back there. Do you reckon Amy manual therapy should be a standalone intervention? Or should it all always be delivered in, in addition to exercise as an adjunct? Or does it depend on the person? Do you have a strong opinion on that question?
Amy McDevitt:
Yeah, I think, you know, I, it should never be a standalone. First of all, I don't ever see it as being a standalone. And I, I think the way I practice and the way I teach is we, we have these clinical practice guidelines that have, have really done a good job in distilling down lots of information and research. And I think we have grades for, you know, the, the different types of interventions. And so, very rarely do I believe either manual therapy or exercise is, is, should be totally done in isolation. I think there's more of an argument for exercise based on where someone is kind of in the continuum of care and where they are in terms of timeline for tissue healing. So I don't, I don't see it as a standalone, and again, I'm gonna come back to the argument. We have support from CPGs that usually those two things go in combination.
Amy McDevitt:
But there are some areas where manual therapy, like for example, the, the CPG for Achilles tendinopathy, so doesn't necessarily advocate that manual therapy should be utilized. And so I teach that we don't necessarily need to use manual therapy in that particular situation. However, every patient is unique. And so if you have a patient that has a high expectation that manual therapy should be utilized, or if you believe there's impairments in in other joints, whether it be the hip or the knee and even the foot and ankle that you believe are contributing to that particular health condition, then I think manual therapy should be utilized. So it's, it's really this kind of hard compromise between, at this point in time, following recommendations, high level research, clinical practice guidelines, and then patient presentation and patient preference. 'cause I think we all know that there's a lot of power in, in patient preference. And so I, I think that's what clinical reasoning is all about. Which is another area that I'm interested in, which is trying to kind of pull all those things together in order to make decisions about what's best for the patient.
Jared Powell:
I'm, I'm a hundred percent with you there. I, I might off a few exercise zealots here, and I, I am and have been an exercise zealot, but I've softened a little bit in my older age, Amy. If somebody comes in, they've got an Achilles tendinopathy and they, you've got an expectation of a calf rub or massage or whatever, yeah, I'll do it. I, I have no qual, I have no qualms about doing that. It's, you know, provided they can afford it, you know, all of these, all of these individual factors that come into play, they understand that this perhaps isn't the thing that's gonna get them back to running. They still need to do their progressive loading protocol, all of these things. Yeah, I'll do it. And I've definitely softened on that over the years because, you know, I'm, I'm not a, I'm not a guru know-it-all that says that exercise is the only thing that's gonna get you back to doing what you wanna do. We have no real evidence to support that, even in the tendinopathy literature, which is basically progressive loading is the way to go. Yeah. That evidence is still fairly flimsy and, and, and weak as well. I just to be clear, as a caveat, I fully support progressive loading and exercise. It is my bias, but I, I have no qualms in adding little therapies on the, on the side, which could help that person's pain. Perhaps not function, but pain.
Amy McDevitt:
Yeah. Nor do I, I mean, I think we both appreciate, you know, especially after some of this work by Mark Bishop and Paul Minkin and Josh Kand looking at, you know, patient expectation for care. And this was across different body regions. So looking at individuals with low back pain and neck pain and shoulder pain, we do know that it matters if they get the care that they're expecting. And so, as painful as it might be for you and I to do a calf rubbed down or an ultrasound , I'll still use it because, and as you could probably attest to, the patients are like, that's great. I feel so much better . You know? Yeah. And so it might tell me to do it once in a while. I'm more speaking about ultrasound, I think, than anything else. 'cause I have particular biases against, you know, using that. But anyway, I, I think it does, does matter and there's a place for it, and the patients are gonna tell you what they want. And I think sometimes we, we have to listen and, and provide the care that they're asking for, not just the care that, that we believe that, you know, they need. And that's where that shared decision making piece comes in. Obviously
Jared Powell:
100 shared decision making is the basis of all of these clinical decisions that we need to make because we have no gold standard treatment a lot of the time to say this is a high value treatment. It has large effect sizes. It is far better than every other alternative that is out there. We simply don't have that in the field of musculo musculoskeletal pain. A lot of the time exercise is favored. And I agree with this, because it can be delivered at home, you know, in a home exercise program. It can be delivered without delay, without intense supervision. It's generally good for you. It can help reduce pain and increase function as well. Yeah. So the exercise seems to be in a somewhat privileged position there, but let's be honest, in regards to its effect sizes, they are quite modest. And the, the, the quality of the evidence is, is really, really poor, which actually makes our effect estimates a lot more uncertain. So, yeah. So I think when we look at all of that, adding a little bit of manual therapy for five to 10 minutes in a consult, we're, we're not the devils when we do that. You know, and it's not even, it's, it's, it's still evidence-based care, because manual therapy is a proven pain reliever when we look at clinical trials.
Amy McDevitt:
Yeah, I, I agree with everything you're saying and, and you know, I don't know what your perception of me is. I mean, I, I practice manual therapy, I practice exercise, I practice patient-centered care. I think manual therapy for me is just kind of a, a starter to help get the patient moving and, and maybe within session see some changes in some functional outcome or performance-based outcome measure, especially if the patient's expecting it. But for me, manual therapy is kind of the gateway to movement and movement comes in the form of, of exercise and, and retraining functional tasks and things like that. And so again, I'm kind of coming back to your original question or comment, which is I, I think it's, it's one piece of the intervention puzzle. And for me, it probably, I mean, if I had to try to describe how much of the time I'm using manual therapy, I'd say it's probably 30 to 40%. But again, I'm, I'm trying in my mind to tap into those neurophysiological responses in order to then layer in something else, like movement exercise flexibility, strength, endurance, all those other things that I think are really important.
Jared Powell:
Yeah. Yep. That's totally valid. How, how is, how is manual therapy taught in the US at the, at the moment? And obviously you just have your own experiences with where you teach and how you teach. Are you aware of how it's taught in other institutions? Is it, is it, is it progressing towards this neurophysiological contextual kind of model? Or is it, or is it stuck in the, in the antiquated era of, of heavy biomechanical rationale?
Amy McDevitt:
Yeah, I think that's a, a fair question. I don't know that I have objective information about how it's taught. I have anecdotal information. I think it's all over the place. I think you have institutions that I think prioritize aligning more with recent evidence and clinical practice guidelines. And then I think you have institutions that are beholden to whoever is, is teaching it. And so I, I do know that there are some, you know, antiquated models that are continuing to be taught. I still think there's some guru wisdom that occurs out there. And I think you have individuals that are, that are kind of teaching according to whatever guru they learned from that may or may not be grounded in any evidence. And so I believe personally, there's a lot of heterogeneity in the education, but I don't fault people. I think people, you know, I think we all do our best to stay apprised.
Amy McDevitt:
And I think some of us, including myself, are appreciative of the environment that I'm in, which is driven by a lot of research and, and movement in the right direction. And, and so I don't necessarily think I, I fault people. I think sometimes they don't have the resources available, available or, or the bandwidth to kind of further their, their education in a, in a, in a direction that I think you and I both agree, we, we all need to go. But I do hope that we continue to see movement in education. I think it's changed over time in a good way, at least the, the colleagues that I interact with and what's happening, I believe here at my institution, I think we're progressive and I think we're moving in the right direction, but I don't necessarily think that's what's happening across the country.
Jared Powell:
Yeah, no, I'm with you. I think it is changing on average or bit slowly. These things do take time. Manual therapy when you, I don't know how much time you spend on social media, hopefully not much Amy, but if you go on like Instagram and TikTok and all of these things, manual therapy does seem to be predisposed to some, and this is not in, this is usually not in physical therapy. Sometimes it is in physical therapy, but it's some weird and wonderful things that people are using manual therapy for, like releasing trauma like psychological trauma from their youth and past lives by using manual therapy, by digging their hand into the SOAs or something mad like that. For some reason, manual therapy seems to attract a lot of these very weird, wonderful alternative models. Yeah.
Amy McDevitt:
Yeah.
Jared Powell:
Have you seen any of that stuff? I've
Amy McDevitt:
Seen, I've seen stuff.
Jared Powell:
. It's mad. Yeah. And I think it makes manual therapy a a easy target because a lot of these quacks, and I will say quacks because it's pure pseudoscience that they're practicing use manual therapy and that tarnishes that particular treatment.
Amy McDevitt:
Agree. And I think, I think to your point, one of our other problems is like a branding issue. Like if we can't with clarity define, you know, what it is and how we do it and why we do it and what it actually means, then I think we're a target to those fringe voices, you know, and those, those fringe opinions. And so I think there is, you know, there are individuals who are interested in clarifying this. I think that the, the paper that you mentioned initially by Jason Silverdale and colleagues searches to, has sought to better define it. I think there's some initiatives from the NIH to kind of better define things like manual therapy and even define mechanisms in order to really foster, I think more understanding and a and a little less heterogeneity and a little less, I would say ridiculousness,
Jared Powell:
Ridiculousness is, is well, well articulated. I like that. And are you aware of any mediation analysis going on or have been conducted exploring mechanisms of manual therapy? Are you involved in any research like this at the moment?
Amy McDevitt:
No. I mean, well, yeah, I mean, I, we so Chad Cook has, has really invested a lot of time. I think one of his initiatives is, is Force Net, which is a group that has come together with a lot of basic scientists and, and researchers to really explore mechanisms based research across multiple professions. So it includes chiropractors osteopaths, physical therapists, and then basic scientists to really start to kind of pin down force based manipulation and, and sort out mechanistic research. So I think he's really been a driver in this. And the reason why I bring that up is he pulled me into it to a recent study. So this was a grant that was funded by the Foundation for physical therapy. So this is specifically Catherine Patela and Stanley Paris have wanted to fund research and manual therapy through the foundation.
Amy McDevitt:
And so the grant that Chad was awarded, I think it was 2022 or 2023, is, is looking at mechanisms research. So one of the, it's called the SS MEC trial. So there's a protocol that we published on that trial and we've started recruitment. We started recruitment in January, so all of us there's three of us that are kind of the main sites. We have Duke University, we have Brian O'Hare who's been collecting data at St. Joseph's and, and myself over here at University of Colorado. So that's a study where we're looking at resistance exercise is, is one arm and then manual therapy as another arm for treating individuals with chronic neck pain. And the eventual analysis will be what you're describing, a mediation analysis to really kind of look at specific and shared mechanisms. And then, you know that that clinical outcome is gonna be the promise tool to look at pain interference and function and things like that. And so we don't even have enough preliminary data yet to, to make any kind of assumptions, but hopefully in, in two years or so, we'll have a little bit more information or intel about really specific versus shared mechanisms with those two treatment interventions to be able to hopefully drive further research and, and research questions in this arena.
Jared Powell:
I cannot wait for the outcome of that. Thank you for, for all the work that you're doing there, Amy, where can people follow you with your research? Are, are you on Twitter? Are you online in any capacity? Yeah,
Amy McDevitt:
I'm on, I'm on Twitter. I don't, I don't do a whole lot. I follow information, I follow people. I get a lot of intel. Once in a while I, I push stuff out, but I, my Twitter handle, I think is a w McDevitt, DPT something, something along those lines. I'm on LinkedIn. I'm very active with the American Academy of Orthopedic Manual Physical Therapist, so it's called amt. I serve on their board, so I'm very active with that organization. But as far as finding me Twitter, LinkedIn, my email address, which you're welcome to, to publish, we
Jared Powell:
Won't in your won't, we won't publish that. We don't we don't, we don't, we don't. I mean, I, I trust all the listeners that are out there, but there's always one or two rogues, so we won't publish that. We'll, definitely over on Twitter is, is a good place to start, I think. And then reading all your work as well, and then following that over the next couple of years is gonna be really important for people, because I think what you're exploring and investigating is, is a really valuable topic. So again, thanks for all the work that you're doing, Amy.
Amy McDevitt:
Yeah, absolutely. Anything
Jared Powell:
Else you wanna add?
Amy McDevitt:
I want, no, I wanna ask you a question if it's okay. Okay.
Jared Powell:
Yeah. Well, since I don't know, we'll see what the question is and then we might cut it out. But yeah, go .
Amy McDevitt:
So you've mentioned that you've been kind of doing a deep dive into some of the, you know, the mechanistic research and some of the, the, the papers that we've used to inform our research. Where do you think the power is gonna be in sorting that out in terms terms of may, maybe not just manual therapy, but you mentioned your world is more in the realm of, of exercise, but what are your hopes in terms of what you hope this, how will this inform your world and your practice and maybe your future research?
Jared Powell:
So as a starting point, I think understanding how and why is a basic scientific necessity. Like it's a, it's a hallmark of science. If we don't have a causal explanation of how something works, then I think we're struggling to call ourselves a scientific profession, first and foremost. Otherwise, it's all mysticism and woo woo. We have a lot of theories. We've been theorizing about things for thousands of years, right? From why is it cold in the winter to blah, blah, blah, blah, blah. So like, that's all well and good to theorize, but I think we need to have answers or causal explanations for phenomena in the world. And I think if we apply that to physiotherapy, we have to apply that to our treatments. And, and it's, when I, when I reflect on where we've come over the last 20 or 30 years with the advent of evidence-based medicine, it's all been well and good to establish effectiveness, sometimes efficacy, sometimes not when we compare our interventions to sham.
Jared Powell:
But the next step is to developing or understanding causal mechanisms. So I think as a primer facey kind of aspect, it's, it's a, it's a necessity of science. And then as we go forward, we might be able to use some of the information that we derive from our research to optimize and make more efficient our treatments. So we're not targeting things that are completely unrelated to a clinical outcome. We're targeting things that we know have evidence that orly produce an outcome of interest, say reduction in pain, or an improvement in function. So I think that's why I'm attracted to, to mechanistic research from a scientific 'cause I'm a real nerd about the philosophy of science and then how do we improve outcomes. Because when you look around the literature, it can be pretty underwhelming of the outcomes for physiotherapy type treatments, including manual therapy, exercise, and all of the above. And for me, I feel like a bit uncomfortable with that. So how can we improve it? And perhaps it's through a better understanding of causal mechanisms.
Amy McDevitt:
Yeah, and I think what I would add is that, you know, even though the, the study, for example, that we're, we're working on right now is only looking at two interventions. One is manual therapy and one is resistance exercise, I think it's gonna inform the results of that and hopefully the future work that we build on from that'll, that'll inform all sorts of different interventions to help us really kind of understand where the value add is. And so I agree with everything you said, and I think it's not just about resistance and monotherapy. I think it's, we're gonna learn a lot about a lot of different interventions that we utilize when we, we sort this out a little bit more.
Jared Powell:
Absolutely. And I, I do think if I was to get my crystal ball out that these shared mechanisms that you've written about so, so well and talked about really articulate articulately today, pardon, pun stuttering when I'm saying articulate, I think that's, I think these shared mechanisms are really gonna be an important feature of a lot of our treatments that might end the culture war debates that we, that the endless culture war debates that we have about this versus that, that's better. I think it's gonna, yeah, it's, it's gonna help that.
Amy McDevitt:
Yeah. I hope so. I hope so.
Jared Powell:
Good. Well is there anything you wanna add, Amy, before we let you go and you can get home and, no
Amy McDevitt:
I, I think the only thing I would add is I, everything that I've talked about today is, is in every way, shape or form having to do with all the people that have mentored me along the way. And so I think as, as an educator and as a clinician and as a researcher I, I can't speak enough about how important it is to, to have really important mentors that help kind of guide you and continue to push you to, to learn and grow. And so people like Chad Cook and Paul Minkin and Josh Cleland and Suzanne Snores, all those people have kind of gotten me to the point where I am now. And I just wanna provide a little bit of gratitude and, and recognize those people that that kind of got us where we are.
Jared Powell:
Absolutely. Very well said. Amy McDevitt, thank you very much for coming on the show and we'll talk to you soon.
Amy McDevitt:
Thank you so much. This was so lovely to, to engage with you.
Jared Powell:
Cheers. Thank you for listening to this episode of The Shoulder Physio podcast with Amy McDevitt. If you want more information about today's episode, check out our show [email protected]. If you liked what you heard today, don't forget to follow and subscribe on your podcast player of choice and leave a rating or review. It really helps the show reach more people. Thanks for listening. I'll chat to you soon. The Shoulder Physio Podcast would like to acknowledge that this episode was recorded from the lands of the Ang people. I also acknowledge the traditional custodians of the lands on which each of you are living, learning, and working from every day. I pay my respects to elders past, present, and emerging, and celebrate the diversity of Aboriginal and Torres Strait Islander peoples and their ongoing cultures and connections to the lands and waters of Australia. I.
