505- Exploring Neurophysiological Effects of Upper Cervical Adjustment

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. On today's episode, we are back with more brand new research, another fantastic study that expands our knowledge of what an adjustment can do. We're gonna dive into what it is, the take home messages and even a little bit of really interesting information about how an adjustment works. On today's episode. Before we get started, lets talk about neck care, the best objective assessment tool for the cervical spine. Neccare.com, check it out. They will hook you up with 10% off your first year by being a listener of this podcast. Massive benefit right there. Check them out@neckcare.com but as I said at the top, we are talking research. Incidentally, we're talking also about research in the cervical spine. This is titled Selective Improvement in Neck and Limb Motor Control Outcomes Following Treatment of the Upper Neck and Spine A Repeated Measures Cohort Study. This is a brand new one. Of course we will drop a link down in the show notes so you can check it out and there's a lot of good information coming your way. Today we're going to talk about an overlooked area in that overlooked area in many cases seems ironic almost the occipital Atlanto joint CO&C1 and how addressing dysfunction here can selectively improve neck and limb motor control. Again, this comes from a brand new study published in the Journal of Integrative Neuroscience. Link down in the show notes and this is one of the first to look at this specific region's impact on motor control across the body. So if you've been in practice, like any amount of time, you've seen the patient that probably just couldn't get back to full strength, just couldn't get back to their full range of motion, whether that's their shoulder, their neck or even their lower limbs. Despite resolving their pain, their pain's totally gone. They're feeling great, but they just can't get that strength or range of motion back. Now clearly when we're talking about strength, I'm eliminating the fact that there's some, you know, direct reason on why there's a limitation of strength. But when it seems as though everything should be fine and it's not, whether range of motion or strength wise, something is fishy, right? So it's a matter of determining, it's you and myself, it's our job to say what's going, going on. And often when you look one level deeper, it's because motor control just isn't about muscles. It's about the nervous system's ability to coordinate, and that's a key word here, coordinate those muscles and those movements. And here's a quote from the authors that I think puts it really well. Sensory feedback from the upper cervical region is used by the central nervous system to stabilize the CoC1 joint for leveled vision and to assess head position, which is used in sensory motor integration of the neck and upper limb motor control. So when that sensory feedback loop is off because of joint dysfunction, restricted motion, chronic pain, you name it, there's a lot of things that can cause that dysfunction. Your patients may be running on a really compromised motor control program in their brain. So what this study did is try to say, well, if that dysfunction is addressed through manual therapy, through spinal adjustments, what happens? And I think you're gonna love the outcomes. We'll also talk about our current understanding of how this works, which I think is really, really critical as well. That it's not, it's not super esoteric, and we'll go through that in a moment. But in this study, they looked at 22 people with joint dysfunction at CoC1 and with chronic musculoskeletal issues. This was a repeated measure study. So each participant acted as their own control with two baseline measurements before treatment to ensure that any changes weren't just from kind of learning effects or familiarity with what was going on. Now, in terms of the spinal adjustments, they use something called the OTZ system. Totally unfamiliar with that, but it started with a high velocity, low amplitude thrust to the COC1 joint and then addressed other spinal regions as needed. Frequency on this one twice a week. Patients were seen twice a week until 80% improvement in symptoms, usually over five to 15 visits. So I say pretty standard in terms of how that was laid out. And the measurements were shoulder range of motion, force production of the neck, upper limb and lower limb muscles, grip strength, and EMG analysis. So what did they find? They found that without treatment, impairments in the neck and limb control group persisted. So there was no change between the two baseline measurements. But with treatment with care, selective and really meaningful improvements were found pretty much across the board. So what does that include? They saw that there is significant improvement in shoulder abduction. They found that there is significant improvement in shoulder extension, significant improvement in SCM peak force, significant improvement in upper trap peak force Significant improvement in quadriceps peak force and a 51% improvement which was clinically meaningful in dash score, which is disability of the arm, shoulder and hand. So the authors put it this way. Selective improvement in neck and limb motor control outcomes post treatment suggest that increased corticospinal drive motor neuron excitability from normalized afferent input may impact gross motor output first. That is massive. Again, pretty much every single one that we went through, everything measured had significant improvement. And you have to remember these were adjustments to CoC1 and they were measuring quadricep, they were measuring upper trap, they were measuring scm. So the question then becomes like, how is this working? Right? I think we all as chiropractors have seen tremendous benefit that may seem non linear in our practice with patients. We also have heard historically with chiropractic, I mean going back, literally the first chiropractic patient, and it not being pain, but being a hearing dysfunction that potentially improved that. There's a lot going on as we talk about every week on this podcast, practically there's a lot going on when you deliver an adjustment. But in this case, let's go one level deeper with CoC1 and explore how is this really working from a research backed science perspective. And a lot of this comes down to neurophysiological chain reactions that ultimately start in the upper cervical spine and then ripple really throughout the entire central nervous system to influence motor control throughout the body. So the really the starting point here is the fact that the CoC1 joint is a sensory hotspot. The sub occipital muscles that surround CoC1 have some of the highest densities of muscle spindle fibers in the entire body. These muscle spindles are specialized sensory receptors that can constantly feed information to the central nervous system about joint position and movement. So their sensory feedback is sent to really important places. Brainstem, cerebellum, cortex via dorsal column cunecerebellar and spinocellubellar pathways. Excuse me. So when CoC1 is restricted or it's dysfunctional, that sensory input becomes distorted and that leads to what's called maladaptive sensory motor integration, smi. That's basically the dysfunction. So you can think of it like a bad signal in your body's awareness system. This affects movement control throughout the body, not only in the head and shoulders and neck, but also even down to the lower limbs. So when we go again, let's go one level deeper into spinal dysfunction and how it can alter cortical processing. So chronic joint dysfunction can Cause a few things, none of which are advantageous. One, increased inhibitory activity in the neural circuits. Two, reduced corticospinal drive to the muscles. That means weaker activation potentials and changes in motor unit recruitment patterns. So this is some of the reason why someone with chronic neck or spinal issues may have lower muscle strength challenges or altered activation patterns even when they're not in acute pain. And this is important to keep in mind as, again, as you think about the patients that you're seeing in your practice, in going beyond just the pain alone and into human performance, whether that human performance is at a professional athlete level or whether it's at a I just want to get up and move around kind of level, all of this matters. We also know that high velocity, low amplitude thrust spinal adjustments restore or have the ability to influence, at the bare minimum, normalizing afferent input. So targeting C1 first before addressing other spinal regions can help normalize joint mechanics, of course, in that area, from a biomechanical perspective, but also reset that muscle spindle activity. And we just talked about how the muscle spindle density in that area is so great. It's an interesting thing. You know, some. Some docs, again, like to start at sacrum, work their way up, some start upper cervical and work their way down. A lot of that comes down to technique. But ultimately, it's important to keep in mind every joint of the spine is not the same. And, you know, there are. There are really different functions, different attitudes, so to speak, in terms of how that segment moves, of course. But when we look at the cervical spine versus the lumbar spine, we look at the orientation of the facets, but also all of that surrounding tissue can vary really heavily in terms of its makeup. So by delivering a spinal adjustment, you're able to help restore sensory feedback, accurate and normalized sensory feedback to the central nervous system. And then when we go into the central nervous system, adaptation with corrected afferent input or normalized input to the central nervous system can then recalibrate the motor commands. So there's been studies using tms, transcranial magnetic stimulation, that have shown spinal adjustments can reduce intracortical inhibition and increase cortical spinal excitability. This results in better synchronization between the motor units firing, which translates into measurable strength gains. Now, again, this isn't something where, oh, you get adjusted and all of a sudden you're a deadlift champion. That's not the way it works. But it certainly is something that you're making a positive influence and a positive Impact. And the paper noted, increased cortical spinal drive motor neuro excitability from normalized afferent input may impact gross motor output first. So really important things to keep in mind, especially as you're discussing this. Now, this is technical. We'll get into how you can apply this to your patient. Communication. But it's really, really exciting. I hope as you're hearing this. So let's also touch on systemic motor control effects. So because upper cervical afferent input integrates directly with whole body postural and movement control systems, the improvements aren't limited only to the neck. So this is where we see things like shoulder range of motion improvements. Why? Because of better scapular positioning and better activation of the trapezius and scm. We see lower limb strength improvements through global reductions in those inhibitory reflex activities and increasing that cortical drive again. And that is really important. So before care, there's a lot of people that come in, almost everybody that comes into your practice, that has distorted sensory input, that leads to maladaptive motor control, that leads to weaker muscle output and restricted range of motion. It's just how it works. After you deliver that spinal adjustment and you start restoring that joint function, you start to get more accurate sensory input. The CNS starts basically a recalibration process to a certain extent. There can be improved cortical drive, and then that can lead to stronger muscle output and better range of motion. So it's not this magic thing. It's really neurophysiology, physiology in action in your practice. So for many of us, these patients, many patients we see are looking for pain relief, but. But many want improvement in function after that in human performance and the ability to stay as well as they can, as long as they can, doing the things they love with people they love, as I like to say. And that's function in a nutshell. So the fact that there can be things like quadriceps strength improvement after treating the upper cervical spine, it not only suggests, it really highlights the central nervous system influences that we have when we deliver the adjustment beyond the local effect. And a couple of weeks ago, I was discussing always looking at the next joint somebody comes in with a cervical spine issue, always ensure they look at the shoulder. If somebody goes to the shoulder issue, check the elbow and the cervical spine. Always look towards the next joint or the spinal region as part of your evaluation. And I think that this just speaks to it again. And I'll just continue to encourage everybody not to become so myopic, too myopic. I should say looking at the area of pain alone because you wanna be a pain relief specialist and you don't wanna feel like you're selling or taking advantage of somebody or whatever those excuses are that go on in many chiropractors minds trying to do the right thing, but actually encumbering their patient's ability to get maximum benefit. So as with everything, there's a continuum. But understanding the research of how things, how the. How the care that you deliver, I should say, can improve people beyond the local effects is something that we all should consistently be reminded of and consistently remind our patients of as well, because I can guarantee you they have no idea. So as we're learning, as you're learning, I hope you're able to take some of this knowledge and communicate it to your current patients so that they can appreciate the depth of what you are providing with them. So this study aligns with broader research that has come out showing that the spinal adjustments that are delivered can do things like reduce cortical inhibition, improve cortical drive, and enhance neuromuscular efficiency. So it's another thing, you know, when you adjust, you're not just, you know, helping the joint move better, you're really recalibrating the body's control systems, which is really, really impactful. So in practice, don't overlook the upper cervical spine. Even if there's things going on elsewhere. It's probably not a bad idea to check the upper cervical spine with patients, especially if they're coming in with neck, shoulder, or even lower extremity issues. Looking beyond the pain, even if the patient reports low pain levels, making sure you're going through your functional assessments, whether that's DNS, SFMA strength test, range of motion. However you apply it, make sure you're doing those things because that helps you expand beyond just the pain relief alone, which is really. Most people are looking for pain relief, but ultimately they're not looking for a chiropractic aspirin. They're looking for the ability to live their life without having to constantly battle back and forth between pain. And that only comes when their threshold increases. Also educating patients, letting them know that you're not addressing just their pain, but how their brain and body communicate for better performance and a lower risk of re injury. And then documenting, of course, those functional changes using those objective measurements, grip strength, range of motion, force output, however you do it, documenting that each and every step along the way. So I loved this study. I think, again, it expands the knowledge of how an adjustment works. It helps highlight Some really important things that all of us need to keep in mind. And it also continues to build on the breadth and depth of what we deliver with our patients each and every week. Now, before we wrap up, if you are on the smart Chiropractor email list, check your emails because we have an open enrollment period going on for Patient Pilot right now. If you have more than a few inactive patients, if you've been in practice more than a few years and you're not consistently reaching out to your list, you're just missing the best opportunity to engage with your people, which to me is just a baseline thing of being a good doctor and a good chiropractor. And the benefit is some of them probably each week will come back in and reactivate. That's what we do with Patient Pilot automated messaging. Over 65 campaigns you get to choose from. I wrote them all, they're scienced back. I think they're pretty good. We send millions of emails on behalf of hundreds of doctors. We would love to have you on our team impacting the world by ultimately reaching out to your people. You can put up a social media post, it'll reach 1% of people, our emails 50% plus open rate. So you're gonna be able to reach way more people, way more consistently. That's what Patient Pilot is all about. Reactivations are the side benefit of that. We have special pricing going on right now as well for a limited time, so be sure to check that out. Otherwise, I thank you so much for tuning into this podcast. Thank you for being a chiropractor. Have a fantastic week in practice and I will talk to you soon.

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