Jared Powell:
Welcome to The Shoulder Physio Podcast, a podcast dedicated to exploring meaningful topics in musculoskeletal healthcare. I'm your host, Jared Powell. Before we begin, the primary purpose of this podcast is to educate and inform the views expressed in this podcast by myself and any guests are information only, do not constitute professional advice and are general in nature. If you act on the basis of any podcast episode, you should obtain specific advice from a qualified health professional before proceeding.
Jared Powell:
Today's guest is Professor Steve Kamper. Steve is a professor of Allied Health at the School of Health Sciences and Nepean Blue Mountains Local Health District. Steve is also a prolific researcher and senior editor at the Journal of Orthopedic and Sports Physical Therapy. I've got Steve on the show today to talk about the placebo effect. Is it powerful, powerless, redundant, or indeed ethical? Are we able to set up a placebo exercise group in physiotherapy trials? Tune in to hear Steve's clear and lucid thoughts on all of these questions and more, and some occasional ranting from yours truly. Without any further delay, I bring to you my conversation with Professor Steve Kamper. Professor Steve Kamper. Welcome to the show, mate. Thanks,
Steve Kamper:
Jared. Thanks for having me.
Jared Powell:
Pleasure, mate. So we're trying, been trying to make this conversation happen for a while. We're gonna talk about the placebo effect and all the machinations surrounding that term 'cause it can be a bit of a murky area. Before we get into this very interesting topic that you've published on, Steve, you're a returning guest to the show with we know you as the kind of research genius, the man behind the research and practice series, which are, which always go pretty viral when they're published in Jo O S P T. So thanks for that. They're super helpful. But who are you, who's Steve Kamper? What do you like to do? What are you into, mate,
Steve Kamper:
Right into? Well, that's, so we got, so who am I, I trained as a physio, but actually before that, trained as an environmental scientist. So I had a career for a little while doing environmental stuff, then trained as a physio, worked clinically, briefly, got kind of seduced, I guess by research. And I think over time what I've realized is what I'm interested in is the power of the scientific method broadly, to answer questions and provide useful information. And what I'm interested in doing is making sure that the people who need or can make use of that power, have the tools in their hands. So that's, whether that's stuff that's published information. So making that, trying to make that a little bit more accessible, but also the methods as well. So I, I, I, yeah, I talk about the tools of science.
Steve Kamper:
So, so understanding how to generate information, which is less likely to be biased, and also the outputs of science. So how do we use what's been published by other people? And that's what I enjoy doing and that's what I, what I like. And you know, I think having thought about that as, as my interest, you know, I ended up, my sort of line of research has mostly been in pain, but I think if I'd come from a different place, I'd still be in research and, you know, maybe I'd be an obesity researcher or maybe I'd be a a researcher in chemistry or whatever else, because I think it's the process which is which I enjoy and which I, I'm, I'm most interested in. And, and so I'm interested in these ideas, which are a placebo being one of them, which to me is just about understanding and sort of explicating the process a little bit better.
Jared Powell:
Yeah. I'm gonna bring up a quote from your paper, which just has just come to mind, and it kind of speaks to your, what you were saying just then. So the idea of a magical black box from which unexplained therapeutic effects bring up is archaic and also unhelpful from a scientific point of view. So pulling no punches there. And I guess that kind of speaks to your personality perhaps, where you are interested in a question and you wanna try and find out a potential solution to that and get away from murky or or gray area. Would that be correct?
Steve Kamper:
Yeah, for sure. For sure. Yeah. And, and I think that's that sort of, I guess reflection of where I've come to and, and, and, and sort more or less stayed in this with regard to placebo, that sort of, it reflects where I'm at on my journey of trying to understand this. I guess I probably started out thinking about placebo as a thing, not too different to another treatment, for example. But I guess the more I thought about it and, and, and, and got into it, it never made sense to me to think about it that way. And, and, and so I guess that, that, that quote there just, it sort of maybe reflects that a little bit.
Jared Powell:
Yeah, no, I like it because it's, it's not just a, with the placebo effect. And something that annoys me is that everything that, and we'll get into this more, more formally in a minute, is that everything that doesn't work by its supposed biomechanical or physiological effect, it just lumped into this, this magical placebo effect. And, and what even is that, and this is why I found your paper so appealing, is because you actually attempted to unpack what this placebo effect is and, and really define it. And we'll talk about language in a minute as well. But before we get into this, Steve, who are you as a person, mate, outside of research? What do you like to do for fun?
Steve Kamper:
I've always been an, an active person. I like sport. I've played soccer slash football, depending on where you're in the world all my life. So I, and continue to do that when I'm not injured.
Jared Powell:
Do you support a team mate? Have you got a, have you got a Premier League team or anything?
Steve Kamper:
I've got a Premier League team. I, I support Spurs, so I'm super excited. Oh,
Jared Powell:
Steve mate, I'm a GU fan. And this is, this is heresy, but, but Ange is a great signing for your boys. Do
Steve Kamper:
You wanna continue or
Jared Powell:
I'll, my brother's a Spurs fan, and obviously I've had it over him for about 20 years, so it's all good, man.
Steve Kamper:
Yeah, yeah, yeah. So I'm super excited that Angie's taking over over there, so that that's great. Yeah, so like sport I come from a relatively big family. I have four brothers and I have a recently started out on a journey of fatherhood. So I have a seven month old baby Micah, who has changed my world and the way that I look at the world. And, and, and so that, that's been a wonderful new part of my journey, I guess.
Jared Powell:
Congratulations. Nothing better. Thank you. But data to myself, and it is, it's, it's, it's a magical thing. So yeah, shout out to you and your, and your, and your partner for getting it done. Congratulations. I just wanna go back to football, soccer for a minute. Matildas, Steve, you you're following the Matildas closely.
Steve Kamper:
Absolutely. Yeah. Yeah. So that, that's been, yeah, amazing and, and amazing being, just having someone who's sort of been involved playing and, and, and watching football over a long period of time. It's yeah, wonderful to see the sort of explosion in, in, in women's football, not just in terms of participation, but also the quality of it in the last two decades is it is just amazing how different the game is over that relatively short period of time. And it's, yeah, the, the quality of football on the World Cup is just, is such a, it's such a wonderful advertisement for the game. And, and obviously all the interest that's, that's going on in Australia and New Zealand moment is, it's just fantastic. And so, yeah, I'll be watching tonight and can't wait.
Jared Powell:
Yeah. Yeah. So for those unacquainted, there is a soccer World Cup going on in Australia right now at the time of recording Australia and New Zealand at the time of recording, it is semifinal day, so the Matildas taking on England tonight, which is a cracker, the old enemy, England. Yeah. And the ashes in cricket finished at two two, so we re retain the ashes. So let's hope we can get another one over England tonight. I'm sure you'll be going for the Matildas, Steve.
Steve Kamper:
Absolutely easy.
Jared Powell:
All right, so, so that's you. I love it. Yes. That's you, that's your research. Now, the placebo effect, so we've alluded to it a couple of times already, or I have, you wrote a paper in the B J S M editorial called the Placebo Effect, powerful, powerless or redundant, a beautiful title there designed to capture attention. I love it, Steve. So this paper was a real eye-opener for me when I read it. I, I think I read it quite early when it came out, forgot about it as you do. And then I came back to it a number of years later and it kind of, it really spoke to me in how clearly you wrote and how we should actually try to understand this thing called placebo from a, perhaps a mechanistic perspective, rather than just lumping everything in contextual effects, all these kind of things into a placebo effect. So before we get into whether it is powerful, powerless or redundant, what is a placebo effect? Can we define this thing? Mm-Hmm. .
Steve Kamper:
Yeah, I mean, first of all, I, I'm kind of excited to talk about this. This is literally one of the, my favorite papers that I've, I've written, and I'm acutely aware that it's a view that's not universally held, the one that I have about this which is fine. And, but it, it's, yeah, so it's, it's nice to have an opportunity to talk about. I will say though, it's not an area that I've had my head in for a long time. So we published this paper in 2013, I think, and yeah, I've, I've, in terms of the where of my energy has been, I haven't really stayed in touch with the placebo literature. So I, I guess I wanna make that caveat upfront. So but I think the basic views that I have haven't really changed, I think based on what I've seen in the interim.
Steve Kamper:
So definition. So, so I think there's a, there's a, there's a real problem at the heart of the definition, and it, it sort of, I think it speaks to the fact that there has been prob ongoing problems in, in people coming to a, a, a consensus about what the definition of placebo is. So we have a placebo effect, so that an effect means something there's something has influenced an outcome. Then the placebo definition by just about anyone's terms, includes something, includes the word inert or some variation thereof. So, so we've, we've got the, the placebo, which, which is something inert, which means doesn't have an effect, and then we have a placebo in effect, which is an effect. And, and so I, I think there's this paradox, no, I dunno, paradox, it's a what's the word? It's it doesn't made up, it, it by, by in a, in a logical sort of way. How do you have an effect if you've got something, which by definition doesn't have an effect. So to me, the concept itself sits on this really unstable foundation. So
Jared Powell:
Yeah, you wrote Steve, the, the paradox of an effect without a mechanism. Yeah. And that, that's odd, isn't it, when you actually think about it and deconstruct it.
Steve Kamper:
Yeah, it doesn't, it doesn't fit with, I guess, well, the way that I view the world anyway. Yeah. And, and, and so I can't make that work in my head. Yeah. and then so I, I, you know, leave others to have hold whatever definition is they like. But, but for me, I've never seen that paradox resolved in any way, which helps me understand the, a placebo as a, as a coherent concept.
Jared Powell:
Hmm. Okay. So let's, can we go, can we do a little tour back into history here and, and maybe perhaps look at where placebo has come from and, and has the tide turned? Was it used to be viewed as powerful and now it's powerless, or where are we at? Is it just used in medical trials these days? Where, like, where are we at with placebos and like in terms of where we've come from history and where we are today?
Steve Kamper:
Yeah, so I mean, the, the, from what I understand, there's a historical definition around there were people who were essentially paid mourners. So rich people who weren't very popular when they died. Their family had people, paid people to come to their funeral and pretend that people liked them. And this, as I understand this, was this, was they, they had some name the placebo, which would related to, to the word. So placebo, as I understand it, the word itself means to please moving forward. It, there was in medical history, sort of over the last two, 300 years, something like that. There was recognition in some fields that actually whatever treatment they were providing wasn't, doesn't really do anything, but keeping the patient happy while they either got better or died was a good idea. And so it was sort of attached to that sort of idea.
Steve Kamper:
Then as scientific methods started to sort of coalesce around or, or, or sort of structure themselves a little bit better, probably in the middle part of the last century, the idea came that placebos could be used in scientific research to try and uncover specific effects. And the whole having a discussion around what specific and nonspecific means, I don't, I, I know that's been used as well, but I don't think it overcomes the fundamental problems, but essentially, so, so placebo, the placebo controlled trial, the sort of origins of that in the middle part of the last century, the idea also from there was that doing these things which were basically keeping people happy, had an effect on health. And, and that sort of came outta that time period and that that sort of grew. There was a, a, yeah. And the name of the, the title of my article, Chris, and, and my article sort of came from a, a study which was published in 1955, I think called The Powerful Placebo.
Steve Kamper:
And by Scientific Standards, the methods were awful, but it concluded that there was this huge effect, or a very important effect, fast forward about 50 years or so to around the turn of the century, and a matter analysis, very influential matter analysis done looking at this it was much more ri rigor and found that maybe the effects were not so not so great. And, and so that paper was called The Powerless Placebo. And so that, yeah, the title of, of that paper sort of plays on those, on that history. So yeah. Is that, does that answer your question?
Jared Powell:
Yeah. Good. And then, so placebo still exists today in various professions, doesn't it? In terms of perhaps homeopathy and without , without trying to denigrate any jobs or professions out there, the placebo is still rife and has a, underpins many of our treatments in physiotherapy as well. So it is, it's kind of omnipresent. It is everywhere on everything that we do. There's a really good paper by Marco Testa and Geo Como Rossini titled Enhanced Placebo Avoid na Placebo. And the, and the premise of the paper is, is basically that within physiotherapy and a lot of healthcare professions, every healthcare profession, there is this contextual effect and contextual factor that underpins, and that is sort of the foundation of a lot of our treatments. You can't get away from it. You, you literally cannot get away from the clinical ceremony. And so that paper was fascinating in that it kind of outlined a thesis that we should enhance these placebo in contextual effects and then avoid these na placebo effects.
Jared Powell:
And I wanna ask you, Steve, is that kind of what physiotherapy treatment boils down to? There's a lot of conversation these days about exactly what the active ingredient of a lot of our treatments are, especially exercise at the moment. We know these classical biomechanical or physiological effects of exercise haven't been born out in causal mechanism research in, in mediation analyses. And that perhaps it might be these psychologically mediated effects that are important. What do you think ma should which be enhancing placebo effects and avoiding placebo effects? Or is there something of more substance underpinning our treatments?
Steve Kamper:
Alright, there's, there's a fair bit in that question. And, and, and I, I think where I'd like to start is, I think what it demonstrates is the fact that talking or thinking about placebo in this context doesn't help us. So, so, so again, there's this, we get drawn back into this idea and, and, you know, you mentioned yourself a lot of, we can't get away from placebo effects and, and, and, and there's no placebo effects, which, you know, same thing in, in, in a, with it, an effect on outcome, which we think is negative. I think the fundamental problem here is thinking that placebo is a thing at all. So if, if we don't talk about placebo at all, let's run an experiment and, and, and not mention it for, for the purposes of what we're talking about here for a second. So we don't talk about it.
Steve Kamper:
And you, and you mentioned the psychological mechanisms and you me mentioned the treatment ceremony and all those sorts of things. For me, thinking about what the influence of of those are on outcome is the way to understand this and, and bringing placebo into the conversation doesn't help us. So if we think that providing a safe and calming environment reduces people anxiety and having people with reduced anxiety means they'll have a better outcome by something, great, let's understand how that works. Let's, by all means, you know, create environments and create treatments and whatever else that reduce anxiety, let's measure all that. Let's, let's investigate it, let's optimize it, let's do all that sort of stuff. We've done ourselves a favor by not mentioning placebo. If it's about, you know, if we're talking about exercise and we're saying, okay, the, actually the, the best hypothetically, okay, the, the, the, the most powerful influence on outcome from exercise comes through social interactions.
Steve Kamper:
And that's because people feel empowered or they feel supported and they feel safe and follow. And you know, that these are all psychological concepts. Say, let's understand the effects of exercise via that mechanism. Again, as soon as we bring placebo into that conversation, we just make it harder. We, we, we, we, we, we've just introduced, you know, we call it, we call it that magical black box. And, and it, it's, it's not only, in my opinion, it, it, it's not only makes things harder, but it, it, well, so it's not only a makes no sense, but it, it holds us back because it offers this out and placebo research such as, it's oftentimes when people start talking about mechanisms of placebo, they, they talk about expectations. They talk about classic conditioning and talk about anxiety and so on. Why not just investigate those things? We've got it, the psychological concepts, we've got some physiological concepts. Let's just invest our time in understanding how those things influence outcome and, and how we influence those things if they're important mediators.
Jared Powell:
Yeah, I agree. I concur entirely. So this placebo is a throwaway term that's, you know, rooted in history that's perhaps redundant. Now getting to the, the last word of your paper, and that instead of just using this throwaway term, we should actually disentangle or deconstruct the mechanisms underpinning these placebo effects. And I think that's, that's a really lucid thing to do to enable progress. And it makes a lot of sense. Following on from that, there's a lot of talk on social media that whenever a specific intervention doesn't outperform a placebo, then everybody just thinks, well, because this treatment doesn't outperform a placebo, then this treatment is a placebo. And it, it sort of gets on my nerves. 'cause It, it doesn't really make a lot of sense. I kind of know the answer to this question that, that you're gonna give Steve, but I, I want, I want, listen, I want you to articulate it as you do for, for listeners. So if we were to compare exercise for some presentation of knee pain or shoulder pain to a de-tuned ultrasound machine that, you know, there, there is no active ingredient in a de-tuned ultrasound or arguably is there an active ingredient in AUN ultrasound? That's another conversation. Then should we compare, should we say that because exercise doesn't outperform this sham placebo procedure is exercise just to placebo that effectively is trying to enhance all of these contextual psychological type effects?
Steve Kamper:
I, I think the resolution to that question for me, and, and again, recognizing that the, the view that I hold on, this isn't universally health built for me, that illustrates the point that we're still considering placebo as a thing and it's saying it's a thing which is attached to exercise, or we're saying it's a thing which defines the control intervention. In your hypothetical trial for me, if, if we did talk about placebo and said, okay, we've got a trial of the exercise versus de-tuned ultrasound. So what that trial does is measures the comparative effectiveness of those two interventions. Let's just consider that controlled intervention and intervention. Why you would design it that way. Notwithstanding, that's what we've got. So you, you, you've got the answer to whether if people are faced with a choice between exercise and de tuned ultrasound, that's the effect that we can expect.
Steve Kamper:
As I said, the the problem comes because we've decided that de tuned ultrasound is a thing, a placebo, and it's a magical thing that we don't really understand. And so we, it, it, it suffers from the idea that we have this idea that the placebo is something which has some effect, whereas actually, well what the way that I would conceptualize, it's whatever that ultrasound involves and that includes the interaction and, and blah blah blah, that has an effect likely maybe, I mean, we'd have to look at that versus natural history to see whether that has, you know, an effect versus history. And again, that's, we can ask, let's say it has, let's say that putting someone, you know, getting 'em into this clinic, doing whatever you talk to them about whatever, doing the D two ultrasound, all that stuff together has an effect, a small effect versus what would happen if that person was just left out in the wild. If we wanna understand that effect, let's understand that effect. Let's estimate that effect. If we wanna think about what the mechanisms of that effect are, let's think about the mechanisms of that effect. But calling a placebo doesn't help us understand that effect. And thereby it doesn't help us understand, doesn't help us interpret the effect estimate that we get when we use it as a control versus something else. So again, for me, the problem comes in conceptualizing that control intervention as a placebo.
Jared Powell:
Good, good. So broader question. What is the role of a placebo control trial in, in modern physiotherapy treatments? For example, exercise, and this is a hot topic, there's always debate about exercise is never compared to a placebo because you can't sham exercise and this is one of the main criticisms leveled at exercise trials. It's always this exercise versus that exercise or this exercise versus natural history or usual care or whatever. So should we just do away with this concept of placebo control for exercise a complex treatment like exercise, like manual therapy for example, and just focus more on, or what are we actually trying to measure here with exercise that we're trying to measure its effect on strength and then his strength and mechanisms that that leads to a particular outcome? And should we just pursue that line of inquiry? What's your thoughts on this?
Steve Kamper:
So my thoughts are, yes, we should get rid of placebo control trial is because, and and the reason I think that is because designating a control intervention as a placebo doesn't tell us what it controls for. Mm-Hmm. And that's the important part of a control intervention. It's the difference between whatever you get there and whatever you get in the index intervention. And, and so typically placebo controls are used to understand a mechanism and that's fine and we can do that research, right? If you wanna understand whether the mechanism by which is strengthening exercise an exercise program, if you wanna understand whether the mechanism is muscle hypertrophy or muscle, then you can set up a controlling convention to do that. But calling it a placebo doesn't help you calling it whatever it is, exercise, you know, without resistance, whatever, you know, it maybe the, the, the description of it has takes more than what you can fit in the title of a study, but I don't see that as the reason for calling something a placebo.
Steve Kamper:
You know, I, I just think this is another way that the concept holds us back because it, because it means that researchers get a little bit of a free pass in defining exactly what they're controlling for. So we can control for attention or we can control for therapist time or, or whatever it is. And that's all fine. And they may be all, they may all make sense in the context of whatever your research question is, but the study would be far easier to interpret if rather than calling that a placebo somewhere, we explained what we're interested in is this particular mechanism and we were interested in controlling for the time that the person had with the therapist because this is our hypothesize mechanism, education or anxiety or just, you know, muscle strength or whatever. It's, so we can try to keep everything else still and manipulate that mechanism. And that's the basis for designing the, the control intervention. This is we're calling a placebo and just saying, well, ultrasound is a placebo type somewhere or whatever else is a placebo that, that doesn't help us. And, and it means that researcher doesn't have to say, here's how I've controlled for all the things that I think are important to control for in order to explain or to describe the mechanism that I'm interested in.
Jared Powell:
Yeah, no, that it's a bit of a cop out really when you think about it, isn't it? So what, what, what's the value really? These studies, they use de-tuned ultrasound as a comparator, as a placebo comparator. I'm making quotation marks with my hands here if you can't see. Or, or a saline injection, which is topical because this disco trial, which has just come out in knee osteoarthritis, and I hosted a debate on the podcast with Christian Barton and Maris Hendrickson on this, and it was a fabulous debate. Everybody should go and listen to it. What's the value of using these quote unquote placebo comparators compared to exercise when there's entirely different perhaps effects or, or mechanisms underpinning each of those interventions? Or maybe, maybe there's shared mechanisms, maybe it is both of them are psychologically mediated and that's okay. But does that comparator give us an answer at all in the real world?
Jared Powell:
Like, are we, are we really gonna go out and perform saline injections, open label saline injection injections of people with knee osteoarthritis, or are we gonna do de-tuned ultrasound? So I guess my question is, is two or threefold, like is there value to those comparators where there might not be any real world application? And from like an efficacy perspective, there are two very interventions. And should we be comparing those two when in an efficacy trial there, there should really be like small fundamental difference between the two, right? So if you're gonna do in a pharmacological trial, you're gonna give a inert sugar pill and you're gonna give a blood pressure pill, right? And then it's quite easy to see the effect there. Bit harder to do in, in physiotherapy trials. So do you have any sort of, of solutions to my rambling thoughts and questions there? Steve?
Steve Kamper:
There's, we have a dozen questions in there. I'll, I'll, I'll try and answer the ones that I remember. So one, I mean, one I think I get a bit, you know, I have a bit of reaction to the idea of real world research because if we're not conducting research in the real world, where are we conducting it? I, I kind of get where that comes from. But I think it's a, a little bit of a sheet. Do get some research that you may or may not like. So I, I prefer not to conceptualize researchers real world research or not real world. You know, stuff that's done in petrol dish is still done in a real world, you know, so i, I think that's, I guess get that off my chest. So in terms of, yeah, let's say your saline injection example, the first thing I'd say is if you weren't allowed to call, if placebo, the idea of placebo didn't exist, if you weren't allowed to say this a placebo trial, then what that means is the researcher has to say, why does this question make sense?
Steve Kamper:
Okay. And so in the context of in the clinic, is a patient ever gonna be faced with a choice of, should I get whatever your real intervention is, or should I get a saline injection? No, it's not relevant. Okay. that I can see. So that's, that's not something that's gonna, that's not a question that's that a patient faces. They're not the only, that, that's not to say that that's the only research that should be done. Okay. If that question is about understanding the mechanism of something for which, you know, and, and, and let's say it's, I imagine I, I dunno, the, the study that you're talking about, let, let's say it's something else that you inject, which you hypothesize influences some cascade which goes inside the human knee juices and, and then has some sort of symptomatic impact, then absolutely that cell injection might make sense as a control treatment begin.
Steve Kamper:
That that, what that does though, it forces the researcher to say, we designed the control intervention this way because here are all the things we wanna control for getting the patient in, jabbing a needle in. And, you know, getting 'em to watch the thing stuff go in and whatever else. What we wanted to check was, does it matter if we have the special stuff which is in viol A versus the normal average stuff, which is in involve B, whether that makes a difference. And so that question that may be a completely reasonable and valid question. So I guess what I'd say is the standard for me, the, the standards, whether research should or shouldn't be done, isn't necessarily, is this the choice that's faced by patients in planning? Maybe to understand the mechanism of something because there, from there we can think about, well, how do we deliver this? Or how do we optimize it or whatever else. In any case though, having placebo as part of the conversation or mentioned anywhere is completely unhelpful in my opinion.
Jared Powell:
Yeah, good. I'm gonna ask you though, to, to give me a definitive answer on like from, from where we are now, we've, we've been researching exercise for 50 years or more in, in musculoskeletal pain. We still don't have any idea really on the causal mechanisms underpinning the small effect of exercise. We're, we're starting to be a little bit more aware that it might be psychologically mediated versus biomechanically mediated, for example. Although I'm not even sure on that. I used to think that a year or two ago. But the treatments that we have aren't set up to really change the mediator of strength. 'cause They're all pretty, those three times 10 with the TheraBand. So, so the causal, the causal chain breaks down pretty early anyway, from what we have. It doesn't seem like strength is a solid mediator of many functional outcomes, except in one study that I remember in knee osteoarthritis where quad strength did mediate clinical outcomes.
Jared Powell:
Anyway, mostly we do see things like pain, self-efficacy, kinesiophobia, fear avoidance, all of these type of things. And again, there's issues with the, with the linguistics of that. I understand that. So, so that's where we are right now. If we set up a trial that compared exercise to de-tuned ultrasound for shoulder pain and we find that there's no difference between exercise and de-tune ultrasound and that trial actually has been done in, in 2010 with, with Kim Burnell. But anyway, we haven't replicated it since for some reason. And there, and surprise, surprise, there was no, there was no difference between the two. What information does that actually give us that, that those two treatments are equivalent or I think that might've been a non-inferiority trial where, you know, dietary ultrasound wasn't inferior to to exercise. Like what, just, can you just run us through what that, from a nuts and bolts scientific perspective that trial gives us, and then how should we sort of critically appraise that and then apply it to our practice? I know not every trial does lend itself to being applied to clinical practice, but most clinicians who read trials will wanna apply it to their clinical practice.
Steve Kamper:
Well, let's make an assumption that the methods are sufficiently sound, that it's producing information that we think is obvious, low enough risk of bias for us to, to have confidence in the, in the estimates. Let's also assume that whatever the index intervention is, the exercise intervention was set up in such a way that it's either reflect at, at worst reflective of, of practice at best optimized to do whatever it's supposed to do. So let's, let's start from that departure point. How do we interpret that effect, estimate of which is let's say, tiny or clinically meaningless? So the really basic interpretation I would argue is in the event that they're the two choices in front of the patient, the best estimate is there won't be any different in difference in effect if they choose one or the other. That's the, in some ways, as assumptions holding in controversial way to interpret that trial.
Steve Kamper:
I think the question is why do you wanna know that? So the next set of assumptions are around the idea that de-tuned ultrasound is not really any different to natural history. So if you assume the de-tuned ultrasound plus whatever, whatever else, it's that, that those patients got. If you assume that doing that has no impact beyond leaving them out in the wild, then you might assume that your index intervention is not worthwhile for a patient. On the other hand, if you assume that the ritual, the dune ultrasound, whatever else that those patients got has some impact, I think then it's then, then the effect estimate is much harder to interpret. And if, if you want to, I, I sense what you're asking is what are the implications of prescribing that exercise program to this patient? And I think that's, that's unclear unless that assumption that whatever is involved in the control intervention has no effect, has no impact over and above natural history.
Jared Powell:
Yeah. So what, what I've been finding in the literature is that basically placebo interventions like saline injections, I'm not, I'm gonna stop saying placebo Steve 'cause I know you hate it. saline injections for knee osteoarthritis perhaps has the same effect size as exercise mm-hmm. . So we're comparing two interventions with the same effect size. Yeah. And we're, and we're acting surprised that they're the same when we try and give someone with knee pain, these intervention like these, it's, it's literally forecast in, in the evidence-based to date. So I don't, I don't know why we're acting like this is the craziest thing that's ever happened when these studies actually are published. And I just don't think they're getting us anywhere because we just keep coming back to the same question. Like, well, okay, well, well how does exercise actually work if we figure out how exercise actually works?
Jared Powell:
So we do more causal mechanism research, mediation analysis, proper exercise trials where, where we set out what we're trying to achieve with the exercise. So we offer a hypothesized explanation as to how exercise works, then we measure the bloody outcomes which we think it might work by and find out whether it does, rather than just doing these weird comparative trials where this intervention riddled with clinical ceremony is equal to exercise, which is riddled with clinical clinical ceremony, but plus maybe some strength and motor control and physiological effect, blah, blah, blah, blah, blah. I just don't think it's getting us anywhere, which is kind of what I'm ranting about. Do you think it's worth, am I on the money here? Am I far off? Where am I?
Steve Kamper:
No, I think this is just about defining the research questions better. And, and, and so there maybe there's an issue here in a view that a placebo intervention is analogous to people getting nothing. And again, it's this is where it's unhelpful to think of a placebo intervention. Mm. And, and, and we'd be better off if that's our, if the research question is, is getting this better than set it up that way? If the research question is something mechanistic that you are talking about, well, let's design a control intervention to target that, that intervention or let's, and or let's do mediation analysis embedded in, in, in a trial with, with a different control intervention. So again, this is just about specifying the question that we're interested in and then designing the control intervention and the outcome measurement to answer that question.
Jared Powell:
Yeah. Easy. So is this is kind of what you espouse and preach in your evidence and practice papers, Steve? Yeah. Which are about how many now? 25 to 30 I imagine?
Steve Kamper:
I think we're at 22 or three or something
Jared Powell:
Like that. Geez. So you're right, we do tend to get a bit philosophical and a bit meta with all this. It's all comes back to the question that we're asking and then setting up the trial to answer that question. Right. And then being careful with your interpretation and not overinterpreting it.
Steve Kamper:
Yeah. And I think that my, my argument would be the introducing the idea of a placebo is counterproductive when we're trying to specify what it's, we're trying to do so
Jared Powell:
Unnecessary.
Steve Kamper:
Yeah.
Jared Powell:
I put up on Twitter the other day a a bit of a thought experiment with how we could do a study trying to sham exercise. And basically the situation is this, let's say for example, we want to figure out the effect of strengthening the rotator cuff or strengthening the shoulder relative to a sham exercise. And that sham exercise is open if anyone's got a good idea. But I reckon even just a simple bicep curl could do. So if you're trying to strengthen the shoulder, then you're not gonna get very far just by doing bicep curls, you might get a little bit stronger. 'cause Yes, we know that the long head of biceps has an effect on the shoulder, but surely it's not gonna be equivalent to an abduction exercise or something like that if we're measuring abduction or external rotation strength. So, but, but I think the positive or the benefits of a bicep curl instead of like a wrist extension exercise, for example, is that the patient would find a little bit more valid. Right? They still think they're, they're moving their shoulder to a point, even though they might not be, but that you can still feel when you pumped your, when you get your biceps all pumped up, Steve, you can definitely feel it around your shoulder. I know
Steve Kamper:
You can see mind Jared,
Jared Powell:
I can see, mate that shirt's, that shirt looks a bit tight. So, so would that be a viable sham exercise in a clinical trial format, do you reckon?
Steve Kamper:
So my view on this I, I don't think we move things on by replacing placebo with jam. I, I, I think all the same things, all the, the same issues apply and I, I'd be in favor of, of that in the bin as well. To be honest, to me what you're asking is, so you have in mind a very specific a question of either does a particular type of exercise strengthen certain muscles or you have a question of does strengthening particular muscles have some symptomatic impact or both? So if you were to set up a trial and what, what one of the, the assumptions that I hear you make is that one of the things which may impact your outcome. So symptoms is credibility of the treatment. So that's what you need to control for with your control intervention. So that's one thing that it needs to involve.
Steve Kamper:
One thing it needs to not involve is strengthening up whatever those specific muscles are. And so, again, I wouldn't call this whatever your abduction abduction versus sham, I'd call it abduction versus bicep curl. And you just need to set out, this is our question, this is our question. If you give someone an exercise, which is specifically targeted to strengthen up whatever rotator cuff muscle versus something which they find actually credible and are happy to engage with and you know, all the performance bias and and detection bias and all that sort of stuff is accounted for via methods, via your control intervention. You know, you, you go through and say, okay, this might be a problem and credibility is the one, this might be a problem. So we've given we've designed it to try and equalize credibility, you can measure credibility as well and make sure that it's been successful.
Steve Kamper:
Then you answer your question, does the strengthening specific exercise or strengthening, does it lead to better symptoms, measure symptoms between two groups, but it calling, you know, saying, oh this is our sham. Is it a credible sham? Just doing that doesn't get to the, the what's important about the sham, which is what it's controlling for. And that depends on your theory. So you've got this theory about muscle getting fatter and, and so on. What does, and you know, what, which part of your treatment is influencing that? So that's what you wanna isolate. The other stuff which might influence the symptoms independent of that is what you wanna control for. So then you set up your treatment, your, your control treatment. That way if you can, you measure strength as well directly, and then you can do a mediation analysis also. Then you can see does treatment A versus treatment B bicep curve versus abduction affect? Is there a difference in effect treatment? If there is, is it by strength? If there isn't, is it because strength doesn't influence the symptoms or is it because our treatment doesn't change the strength? So that's how I would set up that trial.
Jared Powell:
And I think the result of that trial would help clinicians in day-to-day practice a hell of a lot more than invoking a detune ultrasound machine. Because I reckon because a bicep curl, so it has the same contextual features, roughly, roughly speaking, right? In terms of DT ultrasound, you're going into a hospital, you're going into a clinic, you're receiving this, the physio or whatever saying this will do this, this and this and this. The same thing's gonna happen with a bicep curl. Now the issue with a, with an exercise is that there is gonna be a physiological effect, right? Mm-Hmm. some sort of, there could be some anti-inflammatory effect of doing a bicep curl that yes perhaps you wouldn't get from a dietary ultrasound or, so it's hard to control for that systemic effect. But for, for what we're hypothesizing as to be the underpinning mechanism for the effect of a strengthening exercise, it should be that strength mechanism that we're looking for in a bicep curl shouldn't get you there.
Jared Powell:
And then the whole context should be similar between the two groups. So then we're isolating that strength and I think that will give us an answer. So we could stop conjecturing whether strength matters or not, and instead we have actual data on that. Do you think that'd be a, why are we doing those studies? Firstly, is there ethical issues? Is there, are we, are we gonna get to them at some point? Do we, do we know of any in the works? I know there's one being done that's affected sorry, that has used shoulder strengthening versus just active range of motion and passive range of motion exercise. And it shows that shoulder strengthening has a larger effect between the two. But then there's the argument that active range is still kind of loading up the muscle. So anyway, do you know why we're not doing more of these studies? Do you think there are a waste of resources?
Steve Kamper:
I dunno the answer to your question and, and you know, coming back to your hypothesized trial and you know, whether that's useful to, to a clinician, what that doesn't necessarily tell a clinician is what's the best way to strengthen up that rot in the event that that's, that is a mechanism which has some important effect that doesn't necessarily tell you what the best way of doing that is. So again, this just comes back to what, what the question is and, and why do some people do one one trial over another? That's the question that, well, that's what they do. Interested what thinking at whatever else, I dunno the answer to why particular trials have been done or not done. But again, the trial you're talking about is, is looking at a very specific mechanism and that's only one part of the treatment. And so, so there may be a whole heap of other, you know, there, there may, you know, whatever else, how you interact with the, with the patient and whatever else may be important too.
Steve Kamper:
And it may be more or less important than how fat those muscles get. So there it's, from my point of view, they're all reasonable questions also as are questions. Like what if we give them this protocol versus nothing perhaps or some other treatment, you know, some viable options that people have. They're all reasonable questions too. So I, I do think there's for lots of different types of studies, but they all depend on specifying the question and they all depend on the whatever the control intervention is and the index intervention for that matter being designed in such a way that they really get at the question.
Jared Powell:
Yeah, a hundred percent. The reason why I'm sort of banging a dead horse here is that, I mean exercise, a hundred percent of clinicians give exercise to somebody with shoulder pain most of the time, 99% of the time they give exercise because they think it's gonna affect some biomechanical variable. Mm-Hmm. strength, motor control, scapular, dyskinesis, upper trap, bloody tenicity, anything, right? I know that from research that I've done and published is, and same with, same with clinical research is 95% of the time the explanation for exercise for shoulder pain, pain is its biomechanical effect. But we're not testing that biomechanical effect or we can't hypothesize and say that if you do these trials, people aren't really getting stronger, but their pain and function is improving substantially. So we can conjecture that getting stronger isn't really a mechanism there. We we've gotta do mediation analysis research on that.
Jared Powell:
So if we do do that study that I've messily articulated, then at least we, we know that maybe doing a non-specific, I know you hate that, Steve, we're just doing a random bicep curl exercise, which shouldn't be equivalent to a shoulder strengthening exercise and getting stronger in your shoulder. And if that doesn't seem to be different or strength is an a mediating factor of clinical outcomes, then we take away, you don't need to get strong in on average for somebody to get better if they have a shoulder pain issue. And then we do the same thing with scapular dyskinesis. And so we're remove, we're sort of getting rid of all the fat here and so we're sort of left with, well we don't even need to do exercise or we don't need to do strengthening exercise or the ex exercise might not matter, it might be something else. So that's why I think it's a really important question. Otherwise we're just gonna keep doing these same trials and, and, and we're not gonna get anywhere.
Steve Kamper:
Sounds like you better start writing grant applications, Jared.
Jared Powell:
Yeah. Oh, postdoc. We'll get onto it. . But am I, am I making sense there because I feel like I'm just, I'm banging my head against a brick wall when I'm, when I'm reading things on social media.
Steve Kamper:
Yeah, look, I mean it, I I think that that the way to interact with whatever it is that you are coming up against or wanna highlight or whatever else is, is to focus on what question this is answering and whether or not that's an interesting question for you. And so in order to, to understand what that question is, you do really need what the hypothesis is and every good description of the methods, particularly the, the two intervention or the comparison between the interventions. So look, as I said, I, I mean I'm, I don't feel like I'm in a place to say what sort of questions should be answered other than to say that they should be specific questions and specified and, and, and well articulated. So, you know, and because I think there are lots of different types of questions which are, are of value. I, I dunno the field that you are in well enough to have a view on what sort of interventions should be, what sort of questions should be tested,
Jared Powell:
I guess. Yeah. And you are well placed to answer this question, which is, I mean, you kind of, you answered it before, we don't need to be using these placebo controls of saline injections and, and de-tuned ultrasound. We can with the, with the right question in mind and with the right method to answer the question. We can use other exercise methods or, or programs that are controlling for the right thing, right? Which might be credibility and it might be so on and so forth, but it's sort of missing that thing which you hypothesize the treatment to work by. That would still be a valid trial to run.
Steve Kamper:
They're the fundamentals of a valid, because then you have methods that match the question that that's all this is about. Saline injection placebo could, that, that might, well, saline injection control might be a really good way to understand a particular question. So it that I, I wouldn't say that that of itself is not a good control because it might be a good control for, I dunno, a P R P injection or something. So my view here is just that we don't need, placebo doesn't need to enter our conversation. And it, and it, it doesn't help us. And so we can just then judge the control intervention on its merits and, and, and its merits refer to how well it corresponds with the research question.
Jared Powell:
Yeah, that's good. So closing, in closing, I do have heaps of more questions, Steve, but we'll push on the placebo effect powerless, powerful or redundant where you are
Steve Kamper:
Bankrupt,
Jared Powell:
Bankrupt, morally void,
Steve Kamper:
, moral cooked. I think it serves its purpose. Yeah. It's, you know, it's like, yeah, I just don't think it's helpful. A I don't think it, it serves us anymore and in fact it's probably starting to crossover into the not serving from not serving us into being a hindrance
Jared Powell:
Barrier.
Steve Kamper:
Yeah. And so it's, I think it's, from these recent methods perspective, it's a barrier from a clinical perspective, I think it, it's problematic as well. So I, I just don't think it's, i I I think if we can just leave it behind in history, move forward, we're better off.
Jared Powell:
Yeah. And we won't be affected by that. It'll arguably be better off. Good. I just quick, quickly, mate, sorry. The ethical dilemma of placebos. There's some people on social media who wanna know about the ethics of this. Do you, let's say sham, sham,
Steve Kamper:
I think it's the same thing by the way.
Jared Powell:
How, how, how do we say it? Yeah, what about with, with surgery, some people are a bit worried about doing fake surgeries, sham surgeries. Yeah. And then trying to the ethics of that, do you have any any insights onto that or is it, is it just, is it okay because historically was, there's no difference between some surgeries and, and a placebo surgery. So it's okay. Ethically, what are your thoughts?
Steve Kamper:
Are you talking about in the context of a research study or in the context of clinical practice
Jared Powell:
Or both? If you've got,
Steve Kamper:
Because think, I think the answer different. So, so I think stupid problematic in clinical practice to, to be delivering something that you have a view does not have the effect that person thinks it has all. So I, I think, and, and, and I think that's, that applies not just the surgery. I mean the surgery is arguably a, it's, it's a little bit easier to understand the risks of that because they're probably more likely and, and perhaps more severe. So, but ultimately I think it's, it's really problematic to be delivering something to patients that you think doesn't work by the mechanism by which everyone thinks it does. And when I say everyone, the patient, particularly in the context of a, a clinical trial, again, I think this is where we would benefit from not calling these things placebo and saying, I think we need, because the fundamental issue for a trial, in my opinion here, the fundamental ethical issue here is ethical.
Steve Kamper:
Does a person have the capacity to agree to what they're getting? And so I think we need to be clear to a person, you might get this or you might get that, and then a person can decide whether they're willing to take that on. And again, saying you might get and whatever surgery, or you might get a placebo that doesn't help a person make that decision, but saying to them, is all the procedures that you'll undergo or here's all the procedures you'll undergo, you'll get one of these two things that enables a person to make a decision. Again, it's just another place where, so the placebo, you know, surgery trials, they're, they're designed to capture a very specific mechanism of effect and, and they can be perfectly valid question, but in my opinion, they can be good reasons for trying to answer those questions so that I don't have a problem in principle with the way those are designed. Again, it's just for me though, it's just another example of the fact that bringing placebo into the conversation doesn't help us, doesn't help us solve that ethical issue. It doesn't describe in detail what it is the researchers are trying to, to, to understand.
Jared Powell:
Yeah, I just think they use it 'cause it's like a jarring term, right? Placebo surgery versus real surgery and there's, there's no difference. There's
Steve Kamper:
A historical overlay, right? It is my reservations aside, it's an accepted way of, of, of doing business in, in the research world. So I mean that is what is that's fine. It's just a little different view,
Jared Powell:
But yeah. So ethically problematic in clinical practice. Okay. As long as there's informed consent in the research world. Yeah.
Steve Kamper:
Again, it, but it's just another place where it doesn't help us calling something up and see Yeah.
Jared Powell:
Another place where it's redundant or bankrupt. . Yeah. That's good mate. That's the headline of the chat, Steve. Quickly, where can people find you mate? Are you on socials? Are you email man? Where can, if people have burning questions and they want to get all your papers for free
Steve Kamper:
Yes. I'm always happy for that. Always happy to papers out. You can email me, Stephen Kamper at sydney edu edu. Also on Twitter at Steve Kamper, one lowercase. Beautiful.
Jared Powell:
Steve, thanks so much, mate. It's been it's really helpful and I, I highly encourage, and I'm gonna link to a bunch of your work here, Steve, that everyone goes out and reads it. Your editorial and B J s M decade was a real game changer for me. It really, in more succinct and coherent terms, outlines everything we've just sort of chatted about today. And you did it in a brevity of words. I don't know these editorials, I don't know how stressed you get when you write them, 'cause you've gotta, you know, adhere to 1500 words, but you did a really good job. So well done. Thank
Steve Kamper:
You, . Cheers mate. Thanks, Jared. Cheers.
Jared Powell:
Thank you for listening to this episode of The Shoulder Physio Podcast with Professor Steve Kamper. 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.
