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The Prosthetics and Orthotics Podcast
The Prosthetics and Orthotics Podcast is a deep dive into what 3D printing and Additive Manufacturing mean for prosthetics and orthotics. We’re Brent and Joris both passionate about 3D printing and Additive Manufacturing. We’re on a journey together to explore the digitization of prostheses and orthoses together. Join us! Have a question, suggestion or guest for us? Reach out. Or have a listen to the podcast here. The Prosthetic and Orthotic field is experiencing a revolution where manufacturing is being digitized. 3D scanning, CAD software, machine learning, automation software, apps, the internet, new materials and Additive Manufacturing are all impactful in and of themselves. These developments are now, in concert, collectively reshaping orthotics and prosthetics right now. We want to be on the cutting edge of these developments and understand them as they happen. We’ve decided to do a podcast to learn, understand and explore the revolution in prosthetics and orthotics.
The Prosthetics and Orthotics Podcast
Walking Is More Complicated Than You Think with Dr. Steven Gard
What if everything we think we know about human walking is oversimplified?
In this episode, we sit down with Dr. Steven Gard a biomedical engineer and leading gait researcher. We unpack the real biomechanics behind prosthetic design. From artificial heart labs to O&P innovation, Dr. Gard shares surprising insights on:
- Why shock absorption and “energy return” don’t always behave the way prosthetic marketing suggests
- How soft tissue acts as a natural spring, changing everything about how force is transmitted through a limb
- The ongoing debate between ischial containment, subischial, and elevated vacuum sockets — and why no design is one-size-fits-all
- Where microprocessor knees and 3D printing fit into the future of mobility
- The missing link between engineering theory and clinical practice
Whether you’re a clinician, researcher, or just prosthetics-curious — this episode reframes gait in a way you’ve never heard before.
Special thanks to Advanced 3D for sponsoring this episode.
Welcome to season 12 of the Prosthetics Orthotics Podcast. This is where we connect with experts in the field, patients who use these devices, physical therapists, and the vendors who help bring it all together. Our mission remains the same: to share stories, tips, and insights that help improve patient outcomes. Tune in and join the conversation. We're glad you're here and hope it's the highlight of your day.
SPEAKER_03:Hello, everyone. My name is Yoris Beals, and welcome to another episode of the Prosthetics Northotics Podcast with Brent Wright.
SPEAKER_02:How are you doing, Brent?
SPEAKER_01:Hey, Yoris. I'm doing well. Here's a funny story for you. So, you know, my son plays baseball. He's getting ready to go to college to play baseball at a junior college. And um, something actually came across my feed, and it it was this team that's in Texas that uh is looking to do a playoff push. It's a collegiate uh team, independent league. And so this was on a Saturday. So we say, Hey, Connor, is this something that you want to do? He's like, ah, I don't know. You know, I'm getting ready to go to the beach with my friends. Uh but he's like, it's free baseball. So literally we buy a ticket for him to go to Texas, and now he's in Texas, and he starts playing tonight uh with them. So he flew out the very next day. Uh, like we we had no idea where we're sending them. We knew the airport, and we, you know, had a promise that he was going to get picked up by the team, but uh he gets all his room and board covered, and they take charter buses everywhere, and so and he gets to play baseball. So kind of a funny, funny thing. And I look at my wife and I'm like, are are we good parents for this? I'm not sure.
SPEAKER_03:He comes back, okay. I think you're on.
SPEAKER_01:Yeah, it's you know, it was one of those things where the very last game is August 8th, so so literally less than 10 days. So I think he'll be fine. And uh it's it's a ton of baseball in a in a short amount of time. So I'm excited. But anyway, that's uh it's a funny thing.
SPEAKER_02:So who is on our podcast today?
SPEAKER_01:Well, I'm super excited to have uh Dr. Stephen Guard on our podcast today. He went to Northwestern University uh for biomedical engineering, got his PhD in biomedical engineering. He's been around the field of orthotics and prosthetics a long time. He's been uh not only in a research setting, but in the VA setting. And now he's a faculty at Northwestern University, which is one of the most uh famous and renowned universities for prosthetics and orthotics. They've been around for um a long time. And so I'm really excited to hear a little bit about his journey into the field, but then also looking at it from the education side of things, because I know that's actually come up quite a few times over the last uh probably two seasons is the state of education, the state of the student, um, that sort of thing. And he's seen some transitions over the years of not only technology, but also uh teaching requirements, uh educational requirements. And so uh hopping into that. He's also a researcher, uh, he's published multiple publications. Um he is also involved in podcasting, so uh we can chat a little bit about that as well. So I'm really excited to kind of get into it. He's like I said, he's been in the field for a long time. And so anytime that we get that amount of experience, and I know we'd have to cram it into a short amount of time, it it definitely makes it worthwhile for our listeners. Awesome. So, well, welcome to the show, Steven.
SPEAKER_00:Thank you very much, yours and Brent. I'm happy to be here. I'm happy to uh looking forward to our discussion on your podcast.
SPEAKER_03:So tell us how'd you get how'd you get involved in the uh and the uh prosthetics orthotics initially?
SPEAKER_00:Excellent question. I kind of got involved in a roundabout way. Um and let me just kind of preface that with I wish I had known more about clinical prosthetics and orthotics back when I was in high school early on. I grew up in a very small town, a very rural area. There were no prosthetics or orthodists in the town that I grew up in. But I became interested in high school in kind of the intersection between medicine and engineering. And what really grabbed my attention at the time was the artificial heart back in the mid-80s, uh uh getting a lot of publicity in the news. And I decided at that time I really wanted to go into engineering and design, develop, and test and evaluate artificial organs. And so I ended up, uh once I graduated high school, I went to uh Texas AM University, uh, enrolled in their uh bioengineering program, and uh which for anyone who is kind of undecided like me, if you're interested in medicine and engineering, I can't uh recommend highly enough to consider bioengineering or biomedical engineering as a major in college, uh, because you get exposed to a lot of engineering concepts and a lot of uh kind of medical uh uh training as well. And when I say medical, I mean I had uh several years of uh physiology, for example. I had a lot of chemistry, I had courses on biomaterials, talking about the compatibility of materials with the human body and things of that nature. And um so I was very uh, like I said, intent on uh designing artificial organs uh as an undergrad, but I had one of my professors tell me, and he had a lot of great advice, but he said, you're never gonna see artificial organs routinely used in clinical practice in your lifetime. It's not gonna happen. He said, the liability is just too high. And so I started rethinking my path a little bit. And uh at about that time I was also applying to graduate programs, and I applied to a handful of graduate programs across the country. Uh, I ended up coming to Northwestern University for my master's degree. And as Brent already indicated, I was uh enrolled in biomedical engineering, and I needed to seek out an advisor at that time. And some of the most uh interesting work that was being conducted at in the department I felt like at that time was in artificial limbs. And uh under the direction of Dudley Childress, he led the prosthetics research laboratory here at Northwestern at the time. And so I became uh involved in his program. And uh at the time I was very interested in kind of applying principles of electrical engineering uh to OP. So my master's research project was actually designing uh low power circuitry so that strain gauges could be used in uh upper limb prostheses. And it was a project that took me nine months to a year to complete. And along the way, though, uh I became very interested in the research being conducted by other graduate students around me in uh Dr. Childress's laboratory, uh, much of which involved the lower limb and involved gait. So once I completed my master's degree, I decided to go ahead and pursue a PhD because ultimately I knew I wanted to lead and direct research. And so for my PhD research, I actually started focusing on lower limb prosthetics and gait analysis. And ever since I got involved kind of in those areas, uh I've I've kind of stuck with it. Um I continue to do research in lower limb prostheses and orthoses at this point, but I'm very interested in gate biomechanics as well. And um so that that has kind of defined my career, but I will say too, I've I've always tended to focus on problems that I feel are clinically relevant to the profession of O and P, uh, problems that uh users of PO devices contend with on a day-to-day basis, problems that are identified by practitioners as being important to the field and need to be addressed, or those areas in O and P that simply aren't receiving sufficient attention in the field. And so, really, that's how I got into it. And like I said, in retrospect, had I known more about clinical PO to begin with, back when I was in high school, I may have pursued a completely different career path because I I'm just enamored with the work that prosodists and orthodists do. And uh I I can see why it's very appealing to uh people who choose to go into the profession and practice and get involved clinically.
SPEAKER_03:Maybe if you look at the the the engineering aspects of OMP, I think I I we were we were sometimes quite surprised how so many people kind of will will don't seem to rely too much on engineering or kind of shy away from the engineering portion, maybe don't use enough of it in in daily OMP work. Do you do you believe that as well? Is that or we or am I maybe maybe exaggerating it?
SPEAKER_00:No, I think you're actually spot on. Uh it recently uh I've had to come up with um we're starting a new course here at Northwestern for some of our MPO students and uh on advanced research methods. And I need to go back and brush up on some of my engineering training, some of the engineering aspects of my education, simply because I have tended to move away from it a little bit, because I feel like my studies are uh very clinical in nature. And uh I I use what I learned years ago, but I've gotten away from topics such as uh digital signal processing and linear algebra and things like that, for which I had years and years of education, but I just never really used it once I got into the research. It seemed like kind of the research pulled me in other directions. So I would say that observation, yours, is uh very accurate.
SPEAKER_03:Aaron Powell And how do we do that? How do we increase well on the one hand, how do we make it possible for current practitioners to kind of increase their biomechanical engineering kind of knowledge, exposure, uh uh uh and ability?
SPEAKER_00:Let's say that's a great question. And I feel like one of the ways they can do it is by uh getting more involved in the literature, in peer-reviewed literature, such as general prosthetics and orthotics, for example. I'm gonna throw that out there. And uh by engaging in or reading these articles that talk about the latest cutting-edge research and that can educate people and help bring them up to speed on some engineering aspects uh associated with OB.
SPEAKER_03:Okay. And how about like new students? I mean, uh uh, you know, what's the best way to teach them about these uh these these kind of more engineering type aspects? Is it because a lot of the education is quite practical, but this could also, this engineering part could also be in some cases uh, you know, quite a bit more abstract and some kind of bit more conceptual and quite a bit more involving math and stuff.
SPEAKER_00:Absolutely. I agree with you. You'll be surprised. There's a lot of students who come into these uh MPO programs now with engineering backgrounds. Uh you know, a lot of biomedical engineers, but also mechanical, electrical, some of these other areas. And people get drawn into O and P. So uh I would say roughly a third come in to Northwestern with engineering backgrounds. So they have a lot of the math and everything that goes along with it. But then the the courses that are being taught in the MPO programs do teach gate biomechanics. Uh they talk about uh kinematics associated with gate, uh, ground reaction forces, joint moments and powers and things like that. So we do delve into these topics a little bit, not to a real advanced level, because we do recognize not everyone comes in with strong mathematical backgrounds, uh, but these are areas that are being taught in MPO programs uh here in the US these days.
SPEAKER_03:And then like, okay, let's talk about this gate thing, for example. It's like, what makes the the human walk generally so complicated? Because it just, it just like, you know, initially it could seem really simple. It's like, but we know it's really, there's a really a lot going on, and and it's it's actually really very, very complicated, uh complicated. And just looking at, let's say gate, for example, like what makes that so complicated and so difficult to understand and calculate and and then to to to make the right tools for it?
SPEAKER_00:You know, that that's a really good question. And I would have to to uh initially say we don't uh fully understand normal human walking. Uh there were some papers that were published back in the 50s. There was a paper in particular, a seminal paper on the six determinants of GATE. And it seemed to suggest uh or it uh uh indicated that GATE was made up of these six motions for the purposes or attributes, I guess you could say, for the purpose of minimizing body center of mass displacements, thereby saving energy. And people bought into these concepts. They were easy to understand, they were readily observable. Um but what we found is uh back in in the 90s, people started questioning these six determinants of gait and actually found that they didn't have the effects that were claimed by the original authors. And so I think we kind of disrupted this simple model of walking, able-bodied walking in our mind at the time. And then so we started kind of uh looking for what are the uh objectives of gate? What are we trying to achieve? You know, it's more than just putting one foot in front of the other and moving from point A to point B. Uh, there are functional aspects of gait that we are trying to accomplish. Uh, for example, we need to provide shock absorption whenever we walk. Uh, we need to provide a uh nice rocker or rollover shape mechanism with the foot and the ankle. Uh and there's other areas. We do try to minimize uh energy expenditure whenever we walk, not by the ways claimed by the original six determinants of Gate argument, but in other ways that we uh conserve mechanical energy in order to reduce metabolic energy uh from step to step. Um so I I I hope I've answered your question, Yoris. Maybe I I've kind of deviated a little from what you were asking, but uh those were that's what immediately came to mind.
SPEAKER_03:I didn't hear anything because I was just too shocked that we don't understand how we can walk.
SPEAKER_01:Um, I do have a question though for you, uh Dr. Gard, on on some of that. You know, so I uh so I was uh part of uh Cal State Dominguez Hills uh during Tim Stat's last um year. Actually, I think we were the last class when he was teaching there. And then uh we had Ed Ayapa uh uh uh from the Long Beach VA, who I know had done some publishing and and such. But then even over the years, you know, you hear, okay, so you've got the six determinants of gate, and then you have some people saying there's rockers, and you've got other people saying levers uh for for walking. What are some of your personal um not necessarily beliefs, but um things that you know about gate that would benefit clinicians to know at a at a very basic level?
SPEAKER_00:Sure. Uh and and let me let me begin by answering. I I can't say enough good things about Dr. Jacqueline Perry's book on gate analysis. Uh I've actually got uh both editions of her book on my shelf, and I refer to it often. Uh, she provides a lot of good fundamental information, then she goes really in depth on uh various areas associated with gate analysis, uh, with understanding gate, understanding what's going on. But in terms of my own personal beliefs, um uh Dr. Childress and I actually published a couple of papers on simple models of gate, in which we looked at things such as vertical motion of the body whenever you walk. Where does that come from? Uh we also uh investigated a couple of the six determinants of gate and helped uh demonstrate that they're uh not quite correct uh in the thinking or in terms of what they accomplish in able-bodied walking. But I really think foot-ankle rocker mechanisms are key, are crucial for fitting prosthetic and orthotic devices. To be able to duplicate that, what and trying to mimic uh using the term biomimetic, you could say, uh, duplicate what able-bodied people are accomplishing whenever they walk. Um and uh with regard to that too, I I believe that walking speed is a parameter that we really need to pay a lot of uh attention to uh because if you can't achieve walking speeds above about 0.8 meters per second, your gait is going to tend to be very slow, very labored, very energy inefficient. But there are mechanisms that kick in at about 0.8 meters per second and faster, uh, in which you actually can expend less energy due to the mechanical energy you're saving from step to step. Uh due to the inverted pendulum mechanism, if you're familiar with that. Um so I again foot rocker mechanisms I really tend to focus on, and I I pay a lot of attention to walking speed, freely selected walking speed that people are able to achieve with their devices.
SPEAKER_01:When when we're talking about some of the prosthetic, so you have the your normal walking, and then you have these prosthetic devices, and I love that you've really looked into or you've really specialized in the lower extremity prostheses side of things. What are you finding? And I'd love for you to just share a little bit about the uh you know, transtibial say socket and its implications on uh gate deviations, and then uh and then if we can touch on some of the transphemoral um stuff as well.
SPEAKER_00:Absolutely. We've done a lot of work with transtibial prosthesis users uh going back about 20, 25 years now. In particular, I started looking at shock absorbing components for transtibial prosthesis users back in early 2000s. Uh specifically, we were looking at shock absorbing pylons. And shock absorbing pylons at that time had only been on the market, what, five or eight years or so? Uh, by the time uh looking at 2000, 2002. But what we expected to see, what I was hoping to demonstrate, was that people could walk with shock absorbing pylons and reduce impact forces under the foot during the stance phase of gate, essentially decrease uh peat ground reaction forces as a result. So we conducted our study and we looked at the ground reaction forces in all of our subjects walking with and without shock absorbing pylons, and we found there was absolutely no difference in peat ground reaction forces. And at the time we really couldn't figure out why. We thought it was perhaps that uh uh prosthesis users simply weren't walking fast enough to obtain substantial benefit from these components. And um so we ended up publishing our first paper, and we said, well, when people walk faster, they're probably deriving more benefit uh as a result uh by reducing impact forces under the foot, specifically in the vertical ground reaction force. And uh but whenever we started transitioning to transphemoral prosthesis users, doing a very similar study looking at the effect of shock absorbing pylons, we again found no effect of these components on ground reaction force peaks. And uh we started digging a little deeper in that case. In fact, we ended up making a device uh uh that would essentially uh we would put people in this device's apparatus, they would sit on it with their uh prosthesis outstretched, and we would drop them from an elevated uh position, and they would roll down this ramp and strike their foot onto a force platform. So it was an impact testing device, uh you could say. And um as a result, we were able to characterize the effect at the shock absorbing pylons uh independent of walking, independent of user control. And even in that testing, we didn't find that that these components had any effect on peak forces that were being generated due to this impact, which was really perplexing to us at the at the time. So uh myself and the graduate students who were involved working on this project, we continued to think about what was going on here and finally recognized we were probably in error with the model we were thinking about uh for fitting people with these types of components. And uh that is, we weren't really taking into account the interface between the residual limb and the prosthetic socket, and which is a very compliant interface. And in fact, it's been referred to, I've heard, as a pseudo-arthrosis, as a pseudo-joint at that interface. And so it's not stiff. And inherently, that was an assumption we were making when fitting people with shock observing pylons. But whenever we considered the compliance, the soft tissue effect at that interface, it suddenly started making more sense why we're not seeing changes in ground reaction forces when people walk with shock observing pylons. And that's because, in essence, we have two springs in series. So, for any engineers out there, you'll understand exactly what I'm saying, talking about springs in series here of two different stiffnesses. So, whatever spring has the lowest stiffness is going to dominate system response. And in this case, the spring with the lowest stiffness was actually the residual limb socket interface. It was a much lower stiffness uh based upon some of our preliminary testing than of the shock absorbing pylons. And so it doesn't matter if you put a shock absorbing pylon in the prosthesis, um, you're not gonna see an effect on ground reaction forces because that effect is already being dictated by the soft tissue on the residual limb. And but there still may be advantages. I'm gonna throw this caveat out there that people who jog or run on prostheses may still benefit from shock absorbing components. They may also still play uh a role when stepping off of a curb, when uh walking down stairs, for example. Um so I I don't want to completely discard shock absorbing pylons because I I think they still may have benefits. And um you mentioned transtibial, transfemoral. I'm gonna go to osteointegration. We know that that is a stiff or rigid interface in the case of people with bone-anchored prostheses. And it could be that shock absorbing pylons are uh would have tremendous benefit for this population, but I've yet to read any studies where people have tested individuals walking with bone-anchored prostheses with and without shock absorbing pylons. But it's an area that needs to be looked at.
SPEAKER_03:I've got like about all this tracking and and trying to get the right data. I mean, I know in in shoes a lot of people have tried to make 3D printed kind of circuits and pressure circuits, uh stuff like this. And they've tried to make uh sensors. And the idea of a lot of these shoe and soul people is like, hey, we want to get people to wear our shoe soles for a long time, and then we can eventually end up getting the best soles, right? Uh because we have the most data. And it seems like there's a real opportunity for kind of semi-low-cost devices that would be worn either by patients for a long time to help data gathering, like months or years, even. And maybe even like a huge opportunity to get like thousands and thousands of people with lots of different walks and conditions and uh and things to wear these things for a long time, to get a lot more data to really understand this better. Is that could that be a good idea?
SPEAKER_00:Absolutely. I think that's a great idea. Uh, we need instruments that we can fit uh on prostheses and orthoses or fit in them uh so that we can gather information, gather data for people outside of the research laboratory. Whenever we conduct experiments in a motion analysis lab, I mean, those are the best of circumstances. Those are not uh real-world activities necessarily. And uh, yeah, what you're talking about, uh data loggers to collect forces, to collect pressures, to collect uh movements, uh that would be very useful. And you're right, being able to use these instruments on a large number of people, I think would tell us a lot about how people are really uh using their prostheses, how much mobility they actually have from day to day. Um it would provide a lot of information we can't get in a uh gate lab.
SPEAKER_03:Yeah, I think that'd be really cool. And then how about like well, how about just generally about 3D printing? Do you think this is like a detail thing? Is it a transformative technology? What's your opinion about the impact on out of manufacturer on OMP field?
SPEAKER_00:Uh, very good question. I do have some very definite opinions on uh 3D printing. Um, I think it can be very useful for creating interfaces between uh the body and prosthetic or orthotic technologies. Uh, in particular, prosthetic sockets for uh lower limb prosthesis users, I think makes a lot of sense. And I would like to see more of that done clinically, actually. Uh and I think the technology is there that we could we could do that. Um it it concerns me a little bit whenever I see people using 3D printing as simply a manufacturing uh tool to make uh uh components, for example. Uh I don't it because I know the media in particular, the press tends to talk about how these are low-cost devices. You can print them for next to nothing, but it kind of neglects the time that goes into designing the components for uh once they're printed, assembling the components and things like that. Plus, I'm not sure the materials are quite there yet in terms of their strength, durability, robustness uh for making prosthetic components. Um when I say components, I'm talking about not sockets, not AFOs. Uh I'm talking about uh knees and feet and hands and things like that. Uh but like I said, I think there is tremendous potential. I'm excited about seeing 3D printing used for creating interfaces for PO devices.
SPEAKER_01:I think this idea of the interfaces, I think it's very interesting. And, you know, I look back through some of the old uh, like I love looking through old patents, uh, old catalogs. I was actually up at Century College not too long ago, and I got to look through the uh uh the Bennett uh Wilson collection of things and go and looking through some of the old catalogs and such. And, you know, it there seems to be a move towards some flexible sockets. And, you know, all through history, there's been like you have some regions of flexibility, regions of rigidity. I just wanted to get your take on that, the adding of the flexibility, adding of the dynamics, and do you see that as a benefit?
SPEAKER_00:I think it is a benefit. And in fact, I remember uh from many years ago, we had one of our investigators here in the um our research laboratory uh had put together a proposal to develop sockets that were selectively uh compliant in some areas and stiffer in other areas. And I always thought that was an intriguing idea. I've never really seen much done with it, though. Um, but uh I think there would be a lot of benefit for creating devices like that. And and that's something else. I mean, I feel like the field of PO has been historically very much an art form. Uh you get people who really develop an eye and expertise in making good quality devices, but there hasn't necessarily been a lot of scientific rationale for uh creating uh uh for processes, for devices, for things like that. Uh much of what we do, uh it seems like in clinical practice is very biomimetic. We're trying to duplicate uh normal anatomy and normal function. Uh but I think we need to consider kind of alternative means. You and and not just making or providing someone with a rigid socket, but if we can really determine, well, the socket needs to be stiffer in this region, more compliant over here, for these very particular reasons, uh, I think that could help advance the field. I really do.
SPEAKER_03:And if we talk about these interface layer things, I mean, just generally, I think there's so much possible with additive in the sense of the texture and of uh you know, changing kind of internal structures, encapsulated airspace, uh air, and then kind of like customized airspace kind of thing. But we we don't really see that much research. We see a lot of innovators and stuff, people using it at the front line on the same. We see a lot of people trying to develop tools around it. We don't really see a lot of academic uh research where where a lot of stuff is really kind of being applied to the interfaces specifically, applied to OMP, right?
SPEAKER_00:You're absolutely right. We were doing some work in this area 20, 30 years ago. Some of you may recall hearing about SquirtShape, um, in which it was an additive manufacturing method uh that was actually developed in our laboratory by uh one of our uh, he was a PhD student at the time, later became faculty. But uh he modified a CNC machine to control an extruder head and build up a layer, build up a prosthetic socket in a spiral fashion, uh layer by layer, and uh really got some interesting work, got a lot of traction in 3D printing at the time. There were some patent issues we had to overcome. There were some prototypes created that were actually sent out into the field. Uh, we were working close very closely with a uh a prosthetic facility down in the southeast region of the U.S. who continues to use this method for fabricating prosthetic sockets. Um this was also the time whenever uh uh CADCAM uh was very popular in the field. A lot of people were buying into it. And uh from what I understand, uh company, some of the companies started going out of business. Uh people became suspect about CADCAM. They became, they didn't trust it anymore. Uh people started shying away from it, essentially. And I'm hoping that I so I I'm wondering if the profession is a little more cautious about uh kind of buying into 3D printing in spite of all the uh advantages that it it appears to offer.
SPEAKER_03:Yeah, I think well the thing, I think people are interested in using it in daily practice and stuff, and people are using it in places where no other part of work or no other cost structure will really work. But the weirdest thing is like in the interface thing, I'm like, well, this is this is where you need to do this. Because if you could just make it a little bit, you know, wicking of heat a little bit better, if you could just make it a little bit better shock absorber, because we can make a liner that's more of a shock absorber and then wicks sweat and heat better, you know? Absolutely. I I can a hundred percent guarantee you that we can do that without a very quite easy, well, not quite easily getting perfecting is difficult. It's like making a cookie, right? In the beginning, it's really easy, but to make it really good is really difficult. But but but but I can guarantee you you can get a really good result with that. But I'm just seeing like very or comparatively little work going on where the rubber meets the road, if you will.
SPEAKER_00:I know that there are private companies working in these areas. Uh, I'm aware of uh a handful, but I think you're absolutely right, Yoris. There's I I can't really think of any universities currently working in this area.
SPEAKER_03:And then how about like this whole idea of shock absorption and stuff? Because comparatively, there's lots of shock absorption at technologies. You could do a lot of like hydraulic kind of solutions, you could do a lot of stuff, right? And you don't really see, well, you know, is there like a new frontier out there? Because uh, we know, like, for example, with metal additive, we can make uh really very, very compact uh actuators and very compact high-end hydraulics. Um, and very and they're still really expensive, by the way. But we're talking a couple of grand or something. And we're seeing a lot of like innovation on the electric electrical front, right? Sensors, all these robot arm kind of things. But we're not seeing anybody spend like a couple of grand on making the ultimate shock absorber for uh uh some of these prosthetics, and especially like, you know, the below-the-knee stuff, it would seem to be uh that it could be really advantageous there to have like very well-calibrated, very well-functioning shock absorption.
SPEAKER_00:Yeah, that's that's a really good point. I I suspect there are developments in improved shock absorbing components uh that are occurring and people maybe are not recognizing it. And I'm thinking in particular of microprocessor-controlled foot ankle mechanisms. Um, that some of these incorporate uh some of the hydraulic uh mechanisms that you mentioned. Um but people are creating, they're pursuing this line of work for other reasons besides shock absorption. But yet I believe they provide enhanced shock absorption at the same time. So it would be interesting to do a study to see if some of these microprocessor-controlled foot ankle mechanisms don't provide improved shock absorption over mechanical uh devices.
SPEAKER_03:Yeah, that could be really cool. And I think at the same time, I don't know. It's it's really strange that the the the you know, really improved mechanical devices could really uh improve this experience so much uh and the the people aren't really looking at it. So, how about like this education of of uh uh of OMP or education in OMP? Are there are things going well? Is everything perfect there, or do we need to radically change it? What's your opinion there?
SPEAKER_00:I think things are going really well since everyone is tran everyone in the U.S. has transitioned to a master's degree in PO at this point. Um I think we all tend to have very similar uh curricula. Uh we're teaching very similar courses. Like I said, I believe all students are getting biomechanics now. I believe they're getting research methodology courses, uh, in addition to the emphasis, of course, on the clinical aspects of O and P, which they should be getting in these MPO programs. Um, I will mention Northwestern recently went to a master's in prosthetics orthotics research degree, very distinct from our regular MPO degree program. Uh we just launched this last year. We currently have our first cohort of students uh engaged in the MPOR program. And uh the idea here is we're gonna be trained, giving them more intense training in research. The program is a little bit longer, by about six months, in which students will be engaged in an independent research project and ultimately produce a thesis and probably several research publications as a result. So we are creating this specialized degree program for those, the handful of students who come through every year who have been asking us, you know, I'd like to get more research experience. Do you all offer anything like that? Well, now we do. And uh so and I suspect other uh MPO programs may follow as a result. We'll see what happens there.
SPEAKER_03:And do you think, and then uh, and do you think that uh that the education thing like has to be, do we need to update it with new things, like new design tools, things about like additive, more uh, you know, things like FEA uh tools or stuff like that? Is that is that is that lacking in today's uh educational system?
SPEAKER_00:That's a really good question. And yes, I I suspect uh doing FEA, more 3D printing, things of that nature is simply exposing students to more of what they're gonna be seeing potentially in the future. So I can see the advantages of doing that. From what I understand, though, most of the uh O and P educational programs, they pretty much align themselves to uh uh uh KEP standards, what ENCO wants to see taught, essentially preparing the students for their uh uh accreditation exams is where the emphasis is very much placed. But at the same time, I I think we need to kind of push the boundaries a little bit more by exposing them to areas we think are going to become more prominent in the future.
SPEAKER_03:And then how about the the the the landscape for OMP or the market? We we notice a lot of things are changing. Uh companies are getting balt. You seem to be now having these big corporations that kind of have, well, they do they make devices, they uh they make the parts for the devices, they do the fabrication, they do the retail. They seem to be very integrated type of uh firms. Uh Emblem and all these guys. Uh, you know, is that landscape gonna mean that we need to be educating like a different type of person or preparing them for a different type of world out there?
SPEAKER_00:Um that's an excellent question. And I've I've kind of wondered, I mean, I've spoken with some practitioners uh about uh these manufacturers, these companies buying out clinics uh and setting up essentially their own operations. I think we're all kind of sitting back and kind of watching to see what develops here. Uh I don't know if the education is going to change uh as a result. Maybe it should. We'll have to just wait and see kind of uh uh what happens, I think, you know, for the moment.
SPEAKER_03:Okay, okay. And then and across your time, like in working on this OMP, mechanical engineering, biomechanics, like what have been some of the biggest changes? What have been some of the things that maybe uh uh have changed the most since you joined the field and like kind of right right about now?
SPEAKER_00:That's a good question. And uh I'm I'm gonna date myself a little bit with my answer. So one of the early developments when I became when I came on faculty here at Northwestern University was microprocessor control knees. At the time, that was new and novel. What was it? I think the uh, for example, the C leg came to the U.S. in 97, 98, something like that. And again, that was about the time I was through with my education, entering the field as a researcher. And I thought that microprocessor control needs were just kind of a fad. I thought it I didn't think it would catch on the way that it has. However, now I see there is tremendous benefit to these types of components. And uh now we're seeing more microprocessor controlled physical mechanisms. And uh, in fact, we've had been having some conversations with manufacturers about potentially doing some studies in that area uh just to determine what are the benefits provided by these types of devices. So, more and more, I think we're gonna see uh more computers being incorporated into lower limb prostheses in particular, and uh more active control, uh, more use of EMG for uh powering joints, for actuating joints, um, much like the upper limb. Uh and again, we're not actively engaged in that type of research at the moment, but I think it's in the back of our mind. We're kind of watching the field, see what develops, and we may end up moving in that direction.
SPEAKER_01:So I did have some questions for you. I know Northwestern has done a lot of uh when we talk about like the transphemoral side of design, they've done a lot of studying into that. What is your take, um you know, looking at all of all of the history of the importance of socket design for transtibule? And if specifically, there's always the discussion uh ischal containment, sub ischial, uh suction vacuum, lanyard, and then even alignment. Uh, I know even uh so like Willowwood in the early 2000s, they suggested some alternative, alternative alignments that they actually had pretty good results with, but it had to do with the sub ischial socket. So kind of curious to get your take on that.
SPEAKER_00:Yeah, we're actually very interested in different socket designs. Uh, you may recall Dr. Stefania Fitone, who used to be one of the investigators here at uh Northwestern. She's now at University of Washington. Uh, but Dr. Fatone and Mr. Ryan Caldwell uh developed this sub-issual socket design. And um it it they did a number of trials, uh randomized controlled trial on this device, comparing it to issual containment socket. And it did see some distinct benefits in providing this kind of technology. Uh since then, we are continuing to investigate um issual contain uh uh subissual sockets, comparing them to ischial containment sockets because it was interesting. One of the one of the anecdotal observations was some people who were fitted with a subissual socket came in and commented that they their uh uh lower back pain disappeared, it went away, or it was greatly reduced, that they noticed a change. And that got us thinking that perhaps, because we know people who use transphemoral prostheses tend to develop low back pain at a higher incidence than the able body population over time. And um but we don't really understand or know why uh this happens. Why do people develop these secondary health uh conditions as a result of walking with a prosthesis for long periods like that? So we are actually trying to get a study funded right now. Uh we'd got a proposal submitted, we're waiting to hear back on it to uh to see how do subissual sockets compare with uh ischial containment sockets on the potential development of these secondary health conditions. Uh you also mentioned, for example, uh different suspension methods. I think there's uh a lot of work that still needs to be done there as well. One of my colleagues here in the laboratory, uh Dr. Matty Major, has been uh developing a new uh uh pump for uh uh active vacuum uh suspension in lower limb prosthesis users. And that study is uh coming to a conclusion here uh very soon, uh, but they're getting some very interesting results as well. So we are actively engaged in looking at uh issues pertaining to transfemoral prosthesis use. And I I think that's that's gonna remain. There's a lot of good work that needs to be done in this area.
SPEAKER_01:So, as far as like the stability of sockets between the subischial and say ischial containment, and I know there's a lot of people that will say, hey, you know, the your sub ischial socket or your ischial containment socket uh uh really isn't containing anything. Uh what are your what are you seeing as far as stability in these sockets?
SPEAKER_00:That's an excellent question. I'm not sure I can answer that, Brent, but let me give it to God here. Basically, I I I think the stability is about the same between the two based upon the data that I've seen coming out of these gate biomechanic studies. Just to state it a little more clearly, I don't think an individual in a subissual socket is less stable than someone walking with an ischial containment. If if anything, I I I think there are uh distinct advantages, again, to the subisschial that you don't get with an ischial containment. And one is increased range of motion at the hip joint. Uh one, uh another one is increased uh pelvic rotations or the potential for increased pelvic rotations in a subissual socket compared to an ischial containment because you're not constraining uh the pelvis in any way with the prosthesis in that case. And um so those are just kind of some thoughts right off the top of my head there.
SPEAKER_01:Well, and people don't like ischial containment. I mean, even when it's done well, the the uh sitting comfort and all that stuff is is an issue. Um so I I think that's I think it's I think it's great, and I'm glad that you guys are um working on some of that. I'd love for you to kind of uh uh put your time machine hat on and go back, and I'd love for you just to describe to our listeners what you've seen as far as uh the movement from the certificate or certification program, kind of to the bachelor's. We skipped kind of straight to this master's program and what you feel the challenges are uh so positives and negatives of of doing that. And I can just say from my experience with our current residents, our current residents are amazing at East Point. And uh so I I love what the education side is doing. And I I do feel like we're getting a newer style clinician, which I can really appreciate too. And we're moving away from this you have to do everything yourself, and you're working from five o'clock in the morning in the lab till you know 10 o'clock at night when you finish up your uh skilled nursing facilities visits, uh, to something more sustainable and more uh attractive to these younger clinicians. So I just I'd love for you to share a little bit about that.
SPEAKER_00:Sure. Uh and I was involved with the certificate program that we used to have at Northwestern, uh, where uh essentially students would come for a five-month period and they would have to select either P or O to go through the program to get their education, but most would come back for the other discipline eventually anyway. So we were talking at the time a total of a 10-month program. And um at the time, I mean, of course, with that limited time, you weren't able to go as deep in uh uh classroom instruction for uh people training to be proselyteus and orthodists at that time. Uh they spent most of their time in uh laboratory activities, as they they still do in the MPO program. Um but I was uh fortunate to have been involved in some of the early discussions on the field transitioning to uh a master's degree back in the late 90s, early 2000s. And at the time I was somewhat uh hesitant to see the field move in that direction. I didn't appreciate the need for a more in-depth educational experience, for uh a greater diversity of uh education, for the inclusion of this additional material uh to really build a more informed, um uh more articulate, um, more respected practitioner. And uh I even uh had a conversation, a side conversation at one of these uh meetings that I attended on transitioning uh to the master's degree, had a side conversation with a practitioner who impressed upon me the need to elevate the education um uh credentials essentially to enable prosodists and orthodists to be more respected by their peers, by their colleagues, by physicians, by therapists, uh, by others they interact with on this educational team. And um then I was pleasantly surprised to see uh the uh Georgia Tech program, you know, really thrive there for a while uh with their master's program after they transitioned. And uh Northwestern was actually the last school to transition to the master's program uh in 2015, I believe, is whenever we graduated our first class. But it was because the certificate program was just so popular right up until the very last minute. Uh people wanting to get in and do this shorter duration program. And I can understand uh, you know, because the NPO program is really uh it it's a big commitment for students to make. But I think as a result, uh they they really take it seriously. Um I mean, I can remember back uh, you know, 20, 25 years ago, that the mentality of some of the students, not all of them by any means, but some of the students they would look at this time in Chicago as kind of an extended vacation. They really wouldn't take the education part serious enough. And um, it was actually in the education program that we introduced the research methods and the biomechanics course. And in fact, um I taught the biomechanics course for a couple of years there at the very beginning, and uh where we we were exposing students to more mathematical concepts and things like that. And um I I had somebody come to my office one time really upset at the math we were teaching because as he he indicated to me, he said, I'm here to learn how to be a clinician. Uh I'm not here to learn to be a biomechanist. And so I I think as we've elevated the education credential, we've gone to this master's program, students know more is gonna be expected of them. That they're gonna have to learn more. Uh, they're gonna be expected to associate biomechanics with clinical practice. Uh they're gonna have to be adept at research methodology, at the very least, for seeking out research articles and critically evaluating that information uh and determining, you know, was it is good information being presented, or is there a bias to it? Um so I mean I in in looking back, I I think it was a very good decision, an excellent decision to go to this master's program. And I know there's already discussion, there's already speculation that eventually we're probably gonna go to something like a a doctorate in prosthetics and orthotics. And um, so I I I think you know, we'll give it another 10 years, but don't be surprised if there's going to be DPO programs out there. All right, Steve.
SPEAKER_03:I think I think we can talk for hours and hours and hours on this. Uh, but but thank you so much for your time. Maybe we we can have you on again someday. And then uh and uh yeah, thank you so much for your time and your wisdom.
SPEAKER_00:Well, thank you for having me on your podcast. I appreciate it. It's been a lot of fun.
SPEAKER_03:And Brent, thanks for you for being here as well.
SPEAKER_01:Yeah, thank you, Dr. Guard, for uh coming on. This was this was really great. And uh and uh I think there could be a part two because we could go on and on and on, but I know our listeners are gonna get a lot out of this. And I just thank you for uh advocating for a field, advocating for uh great education, solid clinical education as well, and also you know, going against some of the normal conventions that have been, you know, taught throughout history and really focusing on is this a good outcome and are we getting the data that we need to? I think those that combination is really going to push our generation of clinicians to the next level.
SPEAKER_03:All right. Thank you for that, Brent. And thank you for listening to another episode of the prosthetics and orthotics podcast. Have a great day.
