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

Welcome to The Evidence Based Chiropractor, where each week we deliver the latest chiropractic research and marketing strategies, all in the time it takes to get to your office. Now here's your host, Dr. Jeff Langmaid.

Hello and welcome to The Evidence Based Chiropractor. I'm your host, Dr. Jeff Langmaid. This week we are back with more brand new research. This one's about spinal adjustments, proprioception, and pain relief. Those are— that's a great combination for a chiropractic-related podcast. So we're gonna dive into this study, highlight what it says, what it means, how you can use it in your practice, and much more. Before we get started, big shout out to two of our partners, Leander Tables. $750 off their Series 950 table. Step up your clinical game. Uh, you can connect with them and get $750 off by being a listener to this podcast and/or using the code EBC2026. Additionally, Shockwave Centers of America, $500 off one of their shockwave units and a free cart. Big savings just by being a listener to this podcast. Be sure to let those companies know, even if you're just having a conversation, let them know you heard about them on this podcast. That helps for them to continue to support this podcast, which means we can produce awesome content rebates, opportunities for you as a listener. But as I said at the top, today's episode all about the research. Title of the study: The Impact of Spinal Manipulation on Lumbar Proprioception and Its Link to Pain Relief: A Randomized Controlled Trial. We'll drop a link down to this study in the show notes. But I know we've all had patients, we give them an adjustment, they say, I I feel more balanced. I feel like I'm standing a little bit differently. It's one of those comments that we hear day in and day out. Now, depending upon your clinical perspective, you might describe that as improved movement, reduced tension, change in muscle tone, simply feeling less guarded. This study said, what if there's a measurable neurological reason for that experience? What if a spinal adjustment changes the way the nervous system uses sensory information? That comes from the muscles of the low back? And what if that change explains why some people experience immediate pain relief after an adjustment and some not? So this is exactly what the researchers explored in this study. It's a randomized controlled trial, which is great in scientific reports. And again, that title is The Impact of Spinal Manipulation on Lumbar Proprioception and Its Link to Pain Relief. So the researchers compared lumbar spinal adjustments with lumbar mobilization and no intervention. They ultimately wanted to determine whether a single lumbar adjustment could change proprioceptive processing and whether a patient's baseline proprioceptive strategy, uh, or baseline ultimately could influence how much pain relief they experience. So the result's pretty cool. After the lumbar adjustment, the participants in the study did demonstrate a strong shift towards using proprioceptive information from the lumbar muscles. And I say even more interestingly, the researchers found that patients' proprioceptive profile before the care was delivered was associated with their pain response afterward. So it did not simply tell us that an adjustment can reduce pain. It begins to explain something really cool, which is how the nervous system could respond to the adjustment and why different patients might respond differently. So as you very well know, low back pain is, uh, not a small problem. It's the number one cause of disability worldwide. It is something that most people will experience in their life, and it's one of the most common health conditions worldwide. You've heard me say this a million times, but, you know, often there are chiropractors, there are clinicians of all ilks, low back pain, eye roll, boring, no big deal. This is like literally the biggest opportunity and biggest challenge that people are dealing with in the entire world. So there is absolutely nothing boring, nothing eye-rolly about low back pain in any meaningful way. Can we as chiropractors help and do much more than take care of people with low back pain?

Yes.

But I'm gonna— I'll make a controversial statement. I don't think we've done a good enough job taking care of people with literally the biggest problem on planet Earth. There is so much opportunity left there. And we know that based upon the amount of injections and elective surgeries that are being done, never mind the silent majority of individuals who are just living quietly, silently dealing with the issues when they could be living a far better, higher quality of life. So for For many people out there, there is no single identifiable cause or structural problem that explains your low back pain. Textbook definition, nonspecific low back pain. And that's why so many are classified as nonspecific low back pain, no fracture, no infection, no nerve compression. So even though the person has pain and clear functional limitations, the pain cannot be traced in many instances back to one isolated anatomical source or lesion. You know, spinal adjustments are commonly used for these patients, as you well know, and they're supported by multiple clinical guidelines as a non-pharmacological treatment option. So we already have plenty of evidence showcasing that adjustments help improve pain and function. So the bigger question becomes, what exactly happens when we perform an adjustment? Now, if you've been tuning in for 500 and some odd episodes of this podcast, we've gone through a lot of studies regarding this, and we're not gonna stop because this is the, This is the cool stuff showcasing, I say, the breadth and depth of who we are and what we do when we deliver an adjustment. So for many years, researchers out there have proposed a lot of different mechanisms, biomechanical effects, changes in joint motion, changes in muscle activity, spinal cord level neurological responses, brain processing, all of these things. This study focused on one specifically, and that was proprioception. Maybe, maybe the oldest of them all, proprioception. As you know, the nervous system's ability to know where the body is in space and how it's moving without needing to visually look at it. So if you close your eyes and raise your hand over your head, you still know where your hand is in general. So you know where your elbow is bent, you know whether your body's leaning forward or backward. That information is really continuously being sent through your nervous system, the bioreceptors in your muscles, tendons, joints, and other tissues. So one of the main proprioceptive receptors is the muscle spindle itself. Now, muscle spindles detect changes in muscle length and the speed of those changes. So they can provide the nervous system with really fantastic real-time feedback that can contribute to things like posture, movement, coordination, balance, all those things that we're assessing and ultimately helping with every day. And in people with chronic low back pain specifically, proprioceptive processing often becomes disrupted. So, you know, rather than relying on the sensory information from the muscles around the spine, there are patients out there that rely heavily on information coming from, let's say, their ankles, right? So, you know, they call that ankle steer proprioceptive strategy. So you can think of that like the nervous system having different sources of information available. And that's the truth because you have information coming from your feet, ankles, knees, hips, trunk, lumbar muscles, and the nervous system ultimately has to decide which information it trusts and prioritizes, which is really, really fascinating. So that process is called proprioceptive weighting. If the nervous system does not like basically trust or really effectively process the information coming from the lumbar region, it might rely more heavily on other regions like the ankles to maintain balance. And there's been previous research that suggested this type of altered sensory strategy can be associated, probably no surprise, with low back pain, with things like reduced trunk control, increased stiffness, and a greater potential risk for low back pain itself. So the researchers wanted to know whether spinal adjustments could change that weighting, and their hypothesis was pretty straightforward. The that a lumbar adjustment may increase the nervous system's use of proprioceptive input coming from the lumbar muscles. They also wanted to know whether the patient's proprioceptive strategy before care would influence the pain response afterward. So this was a single-blind randomized controlled trial. They recruited healthy adults, nonspecific chronic low back pain, between 18 and 50 years old. There's 200 initial, 206 initial participants, some exclusions. So the final analysis was 142 people. 90 healthy, 52 with chronic low back pain. And they were kind of randomized to one of three groups: spinal adjustments, lumbar spinal mobilization, or no care and treatment. So the adjustment was kind of a side posture, high velocity, low amplitude, pretty straightforward as far as that's concerned. Mobilization, standard mobilization, no intervention, was just resting on your side for 30 seconds basically. So they measured things before and after. And tried to see what was going on. So how do they measure proprioception? This is probably the most technical spot, part of the study. So the participants stood on a force plate, their vision was blocked with kind of opaque glasses, and they wore noise-canceling headphones. The researchers then applied vibration at 60 Hz to two different muscle areas. One area was the calf muscles, the other was the lumbar paraspinals. So the vibration stimulates the muscle spindles and creates the sensation that the muscle is changing length. The nervous system reacts to that altered sensory input and the person's body could sway. So when the calf muscles vibrated, the person typically sways backward. Lumbar muscles vibrated, person typically sways forward. Really interesting. The amount of sway tells the researchers how strong the nervous system is responding to that information. And they calculated something off this called the proprioceptive weighting ratio. A ratio closer to 1 indicated greater reliance on the ankles. Closer to 0, greater reliance on lumbar. So higher score means more ankle-driven, basically. Lower score means more lumbar-driven. So the participants completed these tasks while standing again on a stable surface and then a foam surface as well. Foam surface makes the ankle information less reliable, of course, which forces the nervous system to rely on other parts of the body. So the primary finding was the type of intervention significantly, significantly influenced the change in proprioception weighting. Pretty cool. After lumbar spinal adjustments, participants shifted more strongly towards using input from their lumbar muscles. There we go. Uh, that shift was significantly greater than the shift seen with no intervention. So the high-velocity lumbar adjustment changed proprioceptive weighting more than mobilization or simply resting in the same position. And that's really, really important because the mobilization group controlled for some factors. They were placed in a similar position. They had body, you know, they had hand-to-hand, you know, hand-to-body contact. They had movement, but they didn't get the thrust. And it's something I've said time and time again. There is just something different that happens when you get into that paraphysiological space. Physiologically, it's just different. So there's just something distinct about it. And the researcher's statistical model explained that over 62% of the overall variance in proprioceptive weighting were So it ultimately, when the adjustment is delivered over immobilization, just different things happen. And quite often, not every single time, but quite often better things happen. How do I define better? Ultimately it's based upon helping the patient reduce pain and improve function. So if we get to the really the clinically interesting part beyond that, this study had 52 people with chronic low back pain, remember. So the researchers measured their pain immediately before and after the intervention using a pain scale. The lumbar adjustment Adjustment produced the greatest pain reduction, more so than mobilization and no intervention, which is great. Probably no surprise there. But the response was not the same for every patient. The degree of pain reduction depended a lot on the patient's proprioceptive weighting before care. The researchers found a 3-way interaction between time, intervention, and baseline proprioceptive weighting. What does that mean? The patient starting proprioceptive strategy influenced how they responded to the treatments. Adjustments were especially effective compared with mobilization, participants who already had more lumbar-directed proprioceptive strategy before care. Um, that's just interesting. So among participants with a stronger baseline reliance on lumbar proprioceptive input, manipulation or adjustment produced pain reductions of around 3 points, so 30% or so, depends on where they started of course. But that's, that's a big, big difference. Mobilization produced very little reduction for those types of individuals. And the no intervention group, there was not too much going on there. So that's important to keep in mind. So this is kind of an early mechanistic study, but the concept is really, really important because it suggests that your patient's nervous system may have a kind of sensory profile, think of it that way, that influences how they're gonna respond to your care. That's really, really important. What does that mean? Well, it means some people might need longer care plans. It might be slower to adapt and respond. It means others might move faster. I know we see this every day, but it's just something I think many of us bluntly just don't, it's not what we're thinking about. We're just like, we're going through, we're taking care of our people each and every day. Some people we see get better faster, some not as much. This starts to explain the underlying mechanisms there. Now there's a billion factors beyond just what's highlighted in the study, but man, just starting to chip away at that and get a better understanding. Is so, so powerful. And this gives us stronger evidence than ever that spinal adjustments is not just about moving bones, that it really is about altering, influencing, and updating and optimizing, theoretically, sensory processing. So the rapid mechanical input that stimulates the receptors in the joints, tendons, muscles, ligaments, that travels through the central nervous system. And then your nervous system updates how it perceives and controls that region. And that's really, really impactful. So before an adjustment, the nervous system may be paying quote unquote less attention to that signal. After the adjustment, it's paying more attention to that signal. And that's a good thing when we're talking about being able to establish better lumbar proprioception. It's 'cause tying back to where we started in this study, it just impacts so many facets of life, of functional ability. And that is so, so important. So I thought this study was pretty cool. It's pretty interesting. Again, I'll drop a link down in the show notes, but ultimately it really highlights for us how what we do impacts the nervous system and how it's also not unilateral, right? Different people come in, you know, even with the same condition, quote unquote, chronic low back pain, certain people might be weighting their proprioceptive, not on purpose, but weighting their proprioceptive activity more towards their ankles and feet. Some people are more, so, So as you're going through your movement assessments, whether it's SFMA, DNS, range of motion, whatever you're using, as you're going through your movement assessments, you don't need to have all of the bells and whistles clearly that the researchers had here, force plates and different, you know, different devices. But what you can do is just go through your movement assessments and just really pay attention. You know, how are they swaying? How are they moving? How are they leaning? Or are they not at all? And as you watch them go through that movement assessment that you're providing, it's going to give you a ton of information. And that information, again, I always, I am a marketing guy at heart. So, you know, I think about that through the lens of how do I accurately communicate this? Now, again, I said accurately. Marketing doesn't mean that you're telling a dis-truth. It means you're telling the truth in the most clear and compelling fashion. So helping somebody understand where you think it might be taking them, let's say you're noticing, man, this person probably has a lot of proprioceptive input coming from their feet and ankles. Lumbar spine's not doing too much work here. That would indicate it might take them longer to reestablish a great baseline. That care plan might extend a little bit more because it's not just about pain relief, as you know, it's really about functional ability. Or you're like, wow, this person, they got chronic nonspecific low back pain, but man, their lumbars are fire and great. They're moves— maybe that means that they're gonna be able to get over the hump in a shorter amount of time. Now there's a variety of factors that's gonna influence how you approach that, how you discuss it, But man, talk about a cool study to at least be able to start that conversation. And I'd be remiss, 'cause I mentioned care plans, to not mention careplanpro.ai. If you wanna, I'll say it, sell more care plans, memberships, and concierge programs without having to sell, head over to careplanpro.ai. Big opportunity for you. It is a software, homegrown, home-developed. I wish I had it in my practice, which is why we built it. Docs are, are, are, The feedback has been tremendous. The adoption has been wild beyond what I, what I thought. So thank you if you are a new member to CarePlan Pro. But head on over to careplanpro.ai, check it out. The whole goal of CarePlan Pro is to make it easy for you to be able to present the care the patient needs in a clear and compelling fashion that makes it easy for the patient to start and get the care they need. Nothing more, nothing less. So as we wrap up today, big shout out to RehabFix Hybrid Program. If you're looking to extend beyond the four walls of your practice, Grant and his team, there's nobody better out there. Create more revenue for you, create more financial freedom, and help more people. RehabFix Hybrid Program, I'll drop that link down below, as well as the NovoPulse OA Recovery Program. OA, big deal, hardly anybody taking care of it, massive opportunity for you. And NovoPulse just started a managed service option, which gives you the opportunity to bring NovoPulse into your practice at zero upfront cost. Yes, you heard that correct. Zero upfront cost. Why would not you check that out? I'm gonna drop that down below. Check it out, connect with the team over at NovoPulse. If you're not up to rating a review for this podcast, I would love it if you would take a moment and do so. Additionally, I just want to say thank you for tuning in. Thank you for being a chiropractor. Have a fantastic week in practice, and I will talk to you soon.

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