070- Interview with Clinical Researcher Dr. Charles Penza
11 Nov 2025 · 17 min
Dr. Charles Penza discusses his research on how spinal manipulation reduces pain by changing brain activity. He explains pain as a brain-produced experience shaped by expectation and the central nervous system, and argues that labs need to track real patient outcomes to prove their findings work in clinics.
Chapters
Welcome to the Evidence Based Chiropractor. Providing you with elegant and efficient research based content to help your practice prosper and succeed. Now get ready for a variety of dynamic communication tools designed for immediate growth. Courtesy of your host, Dr. Jeff Langmaid.
S.A. evidence based chiropractor. I am your host, Dr. Jeff langmaid. This week, super pumped got Chaz Penza, my good friend from chiropractic school. I've known him a long time and we're going to talk about the exciting research that he's been doing and, and that I can't wait to dive into. So Chaz, thanks for joining. Pleasure. And tell us a little bit about your chiropractic history. How'd you come to be a chiropractor? How'd you come to sit here today?
First, thanks for having me on. Big fan of what you're doing with Evans Based Chiropractic.
Thanks.
So I guess me as a chiropractor, we graduated together in 2006 from Palmer, Florida. From that period of time I got to work with some of the big names I think in chiropractic. Craig Liebensohn in California along with Craig Morris.
Nice.
Then worked with Don Murphy a little bit in Rhode Island. So that was really great. And then from there came back to Florida because of the weather. Weather, like to surf, stuff like that, play a lot of golf.
Good.
So practiced a little bit and then around 2010 had the opportunity to get back to go back to University of Florida to get my PhD, talk with some of the people there. And then we decided to do that some of the projects and it's really kind of exciting. So hope to talk a little bit about what we're doing.
Right on. So did you, when you were working with Liebensohn, with Murphy, did you feel like you were gonna go the direction of research or did it kind of evolve over time?
What's.
I know, I feel like you're an interesting guy because as we kind of talked about off camera, you like to be a practitioner. You like to get in there hands on and not just be. You like to be a clinician and a clinical researcher. So how'd that come to be?
I think it's always, you know, I think it goes back to almost chiropractic school wanting to understand what is it that we do and how's it work, you know, And I think that really can help us understand our own profession. I think we're the ones who needs to really kind of take a hold of that and figure it out. And while we're going through school, we're getting a lot of evidence and you know, from 2005 on, all through, all through those years, we're getting, you know, some of the effectiveness of, of it. So that was really kind of cool. But we're not, you know, we don't really know exactly how it works. So that's always been in the back of my mind. That being said, I think after school was more about becoming the best clinician I could be. So Riebenson, a lot of the rehabilitation of the spine aspects. Craig Morrison, textbook on low back syndromes. There's a lot of things that we'll treat. Don Murphy, he's an evidence based chiropractor. He's kind of really integrated in healthcare himself as almost like a. The primary spine practitioner models. He wrote cervical spine syndrome. So got a lot of on how to evaluate patients coming in with back pain. What are the contributing factors to it that I can address or look at and then how to treat them. So that I think was kind of where I was going and saw myself almost in that model of wanting to be like a primary spine practitioner.
Right on.
And then in Florida was getting very much into that was sponsored, starting to integrate with Brooks Rehabilitation Hospital, which is kind of a good thing. They had a lot of outpatients and they started to create a spine center and they do research, rehabilitation research with University of Florida. And UF had some really great researchers, Stephen George, Mark Bishop, Jason Benechek, all looking at spinal manipulation.
Okay.
And how they kind of work as well as spine pain. Those factors contribute to it. A lot of conversations, a lot of things going on. Kind of same thing. What are you guys doing there? What's going on? And they started really looking at central mechanisms of manual therapy, how it may relieve pain. And they said, you interested in getting a PhD?
Yeah, there you go.
And that thing of like, man, let's try to understand where this is going and how to do it and almost give back to the profession. That being said, now the PhD has been done 2014 did a bit of a postdoc there as well, but had been back into practice part time. So a couple days a week. I think it really evolved. So my understanding of pain has evolved and then. But how I treat, I think we really kind of get in. When we model people that we, you know, how they treat patients, it's real same way that I treat patients now. You know, you want to get really good at manual therapy, really good at understanding the population that you're seeing and how we kind of fit in and integrate them with other healthcare practitioners.
Right on. And I know that you've been, throughout that time, you've been busy. I think you have well over 12 published pieces with you with your name on the bottom of them. What's tell us a little, I mean, again, we were talking off camera a little bit about how chiropractic manipulation, how spinal manipulation, chiropractic adjustment, how that impacts the central nervous system, how placebo plays a role. Tell us a little bit about what you've been up to. Sure.
So that's a good. Yeah, kind of lead into it. So I think one of the things when we think about chiropractic research, a lot of it has been on what's the effect that it has on biomechanics, how does the spine work, how does it go into that? Now one of the things we also need to understand though is how does it relieve pain? Pain is ultimately a brain experience. So it's an output of the brain, so we have no susception going in, but all these kind of signals and eventually it's an experience that you have. So in some ways, when we look at the evidence, spinal manipulation is more effective than a lot of sham procedures and stuff like that in relieving pain. So how is it influencing? Is it reducing the amount of input that's going into the brain? Is it, do we change how the brain is processing some of that stimulus that's coming in? How are those all things going there? So what we do at University of Florida is I think, really kind of unique because we're not just looking at what are the mechanisms, spinal manipulation, biomechanically, but what are the mechanisms specifically revolved in reduction of pain.
Okay.
And for that, I think when you mentioned placebo, that's one of the ways that we can look at what are the mechanisms in the body that's already there that relieves pain, what mechanisms are involved when it modulates, increases pain or decreases pain, what are those influences? And you can do that really, really well with placebo and give medications and understanding it. And when you talk about placebo mechanism, it's not one. There's multiple mechanisms, neurophysiological mechanism that can reduce or increase pain. So learning those and then the ability to study them now obviously in the last 20 years has gone through the roof with functional imaging. So now we can non invasively study changes in the brain that we're processing these information and do it multiple times with functional imaging because there's no radiation involved with that. And that's exactly what we started doing in some of the things at University of Florida. So we're looking at how does manipulation, we're looking at what are some of the changes involved with back pain and then what are those changes that we see that are, you know, kind of immediately after the manual therapy and at some point. So we've done it right now just pre post kind of stuff. But we know in clinically we don't just treat someone one time, we treat them multiple times. So I think coming down the road we're looking at some of those things where we'll do more of this kind of information. But this, this early stuff is trying to almost get some markers of what do we think is going to happen. Okay, we're seeing early changes. These are some of the changes we see with pain. These are the differences between healthy controls, chronic low back pain patients, and how are we changing it? Because we know we're effective.
Right.
So the question is that we're getting how is it effective, how are we doing it? And the same way we don't treat everyone perfectly, right? Not everyone responds to what we do. So what are some of the things that contribute that we may not be affecting? And that's how we start comparing things or almost a mechanism based treatment plan that we're saying what are some of the mechanisms that we do is exercise the same way? What are some of you, a placebo with expectation and some of those mechanisms. So I think that comes down right now. We're in the beginning of it. I think that's what's exciting for me to understand all that kind of.
That's cool. How do you think, how does functional outcome play a role in that? So I mean, I think from a clinical perspective, when we see a patient, you or I or anybody else out there, you know, we're looking to have that patient walk out happier than they came in. Right. So pain reduction, important component of that and why people pick up the phone nine times out of ten. Now there's also the component to quality of life, functional outcome. Do you see function as a subset of that pain relief? Is it totally different? I know it's a different goal when you break down the research. But do you track function and what's kind of your thoughts on that?
Yeah, definitely. So I think there's a lot of play. So a lot of it start with us with the idea of pain perception. But pain is not only a sensation but also an emotion.
Okay, Right.
Almost by definition it's emotional and sensory experience and emotions what's funny though is pain is not considered one of the primary senses or one of the primary emotions. It's not considering those.
But it's interesting how that works.
So when it comes into that, it's really kind of interesting the fact that emotions are motivators.
Okay. Right.
If you're happy, you're going to be drawn toward things. If it's negative things, you're kind of push away. So the aversive part. So I think sometimes understanding pain, but then also understanding how pain and some of these mechanisms of push function, functional ability are there. It's not linear. I don't think it's, you know, a one to one, but there's a ratio there. And I think that's sometimes another aspect of the things that we do. We do measure different, I wouldn't say functional outcomes. I mean, we measure disability and stuff like that, but we also kind of starting to look at some of the effects on muscle function and how those may go. And if you're reducing pain, your perception of pain, I mean, you engage things differently. So we know there's some neuromuscular dysfunctions that are happening there. And some of those changes, even with people like stiffness in the group, Kyle Chuck and his group up in Canada, looking at how manipulation changes the stiffness, that may change how muscular goes. So you may affect how you're behaving in the short term into those things. But I do think what you're saying though, looking at when a patient gets more functional, re engages into their life, re engaging activities that they love, I mean, that's our goal as a clinician, whether it's, you know, end of the day with their quality of life to be better and their pain may not be completely less and they still might have some level, especially if it was chronic, you know, they're not going to have chronic pain necessarily go completely gone. So their expectation of that, but they may have less impedance to doing things that they love if the pain is dampened, if they understand those kind of things, and what are the contributing factors like sleep, anxiety and things that we can do and then what are some of the manual things that we do. So I think ultimately though, we still may see some things that once patients are relieved from care, there might be ways of studying what are the ones who maintain that ability, maintain that function, what are some of the predictors of that and what are some of the predictors of ones who get relief but then start to lose that kind of their pain comes back period of time, they do well, for a period of time. But then it kind of comes back and look at some of those things, other things related. There are some central nervous system changes that weren't addressed. Some of those connections are still stronger, easier for them to feel pain during an activity. So there's also activity related pain. So that's some of the other interesting. Not just how much pain you have right now, but how much pain do you have when you're walking? How much pain do you have while you're lifting? And can we. You know, it's interesting is that sometimes we're starting to move towards that of measuring pain in different ways, like activity related pain, activity provoking pain as a way that may even be a larger predictor. And we've looked at some of those things. When you look at, there's a whole lot of variability and disability, you know, some have small, some have less. And pain, you know, maybe explains the level of pain they have, explains 20, 25% of that variability. But when you add in activity related pain, it explains a little bit more. So it's an additional kind of explainer that if we can maybe affect these as well, other aspects or other ways of kind of asking about pain, it's a whole pain experience. And when we say what's your VAs? 0 to 10, but trying to get that necessarily more information that eventually affects their pain, their life.
Yeah. That's awesome. What. And with that, I think that you can kind of go exactly where I'm moving, which is what do you see as the next horizons? Like what's exciting to you? I know you touched on a little bit at the top, but elaborate a little bit more in terms of, you know, maybe predictors for patients that are going to be super successful or patients that you can probably expect to see again. And certainly as far as impact on brain function, central nervous system, outcomes assessment, what's kind of the cutting edge or what's on the horizon that gets you excited from a research perspective?
Yeah, I think from a research perspective, I think it's gonna be some of the translation in the clinics.
Okay.
You know, a lot of what we do right now is in laboratories, and that's a different beast than it is in the clinic.
Well, sad.
Yep. So in some of that, we need to kind of translate into that. So I think that's on the horizon. That's things that we're looking to do. As you know, I'm back in clinic, but I want to start collecting data from clinic and doing some of those. So it's more patients that are seeking care and came into this for purpose, but then also maybe be open to us collecting some other things on them. So I think that's on the horizon for sure. And then for me, it's different hypothesis, but one of the ones I'm thinking when we talked about placebo a little bit is that we can start to see there's a lot of variation in how patients are able to modulate pain. So some might be really good at it. Maybe they can really distract themselves from pain, or they have these abilities that other people may not do. We have kind of seen that patients like fibromyalgia and chronic low back pain, their ability to modulate pain is less, but there's still variation in those. So when they come in, maybe some of that. This old idea that chiropractic engages the body's own ability to heal itself might be predictors on this thing. They have good function, therefore they come in.
We.
We treat them, we talk to them, we do different things, we affect their expectations, we create a good bond with them, we understand them to some degree. We're able to say, yes, I think I know what's going on. This is where we might be going. So I think that part of being the doctor also the predictors of them also might be our abilities to engage their own systems that are functioning there and then see with treatment, how long are there certain things that get better with. Are they able to modulate better over time, better? We know some patients with fibromyalgia do well with what we do. So it's not as though it's saying that you can't get better with us, but it's a more predictive that you're maybe have a better outcome sooner. So can I tell someone, hey, you're likely to respond in four to six weeks, couple treatments, better expectations.
Right.
And I can give them a more realistic. Versus you'll be better in four to six weeks. They come in four to six weeks later. They're like, I'm not really there. And now they're frustrated with it.
Right, right.
But you can almost get a better understanding of what we might, you know, what's their trajectory on average over time, and are they maybe a slower trajectory or faster trajectory? Are some of the things that we might be able to kind of look at in the horizon, which I think can help overall? You know, if we are primary spine practitioners, if we understand this research, then we are kind of the ones who can really treat spinal pain, spinal conditions better than others.
Yep. No doubt. Right on so how can people, how can people connect with you? They want to learn more about what you're up to, what you're into, what's the best way.
So we talked a little bit about publications. I was just recently married and I took my wife's last name so my surname changed. Kind of progressive. She thinks I'm progressive. So before that it was gay. So it was Charles Gay and published his app. So it's gay cw. If I'm looking for me some of the publications that I have and talked about but moving forward it'll be Charles Penza. So PensACW on Pubmed and people can more than happy kind of contact. I'm not the media savvy person. I'm not on Facebook, not on those kind of things. So it's not easy to follow me media wise. But hopefully as things like this are going forward, I'll keep in mind that even through you trying to get the information out because I think that's for me I love doing it because it's I learn but at the same time I think, you know, giving that back and making it clinically relevant for practitioners because even for myself when I'm back in clinics I'm not really using changes in brain and how I treat that kind of came in more about early getting good at what we do. But I think at some point we want to start. My goal is to really make it more clinically relevant.
Right on. Cool. Thanks for hanging. So everybody out there definitely check out CWgay Charles Penza. If you're searching on PubMed, it's where the lab meets the clinic. It's really the forefront and what's going on next with chiropractic research and where it's going. So I appreciate Chaz taking the time to come down. I'm sure everybody out there has as well so be sure to check him out, be on the lookout for him speaking at a variety of events, hopefully coming soon to near you. So hope you have a fantastic day and we will talk to you soon.
We appreciate you joining us for this episode of the Evidence Based Chiropractor. Learn more tips for explosive practice development@the evidencebasedchiropractor.com youm can also join the Premier MD monthly membership enabling you to use what you just heard to maximize results in your office. We look forward to providing you with more dynamic communication tools for immediate growth right here on the Evidence Based Chiropractor.
More from Jeff


564- Transforming Back Pain Pathways: Chiropractor-Led Triage in Neurosurgery Referrals


563- How Spinal Adjustments Impact Multifidus Muscle Firing in Acute Low Back Pain


562- New Evidence on Cervical Adjustments: Immediate Effects on Pain and Muscle Response


560- Exploring the Overlooked Connection Between Airway Health and Posture in Chiropractic Practice


559- Vertebral Nerve Ablation for Chronic Low Back Pain After Lumbar Fusion Surgery


557- What Cervical X-rays Really Reveal About Pain, Degeneration, and Alignment in Practice


554- Understanding the Neurological Effects of Spinal Manipulation on Pain Relief and Proprioceptive Processing