The Effect of Axial Load on Cervical Motor Control | Podcast Ep. 315

Foreign hello and welcome to the Evidence Based Chiropractor. I am your host, Dr. Jeff Langmaid. I hope you had a fantastic holiday today. We have a great episode of this podcast where we're talking about a brand new study that came out titled the Effects of Increasing Axial Load on Cervical Motor Control. A lot of clinical pearls in this one, lot of thought provoking statements and some things that I learned. Certainly I hope you learn as well as we break down this brand new research study. But as I said at the top, this episode is devoted to the research. This is a brand new study that came out in Scientific Reports. It's titled Effects of Increasing Axial Load on Cervical Motor Control and it is a good, good one. So how and why is this relevant to you as a chiropractor? A lot of different reasons, but let's just start with when cervical motor control is functioning at its highest level or it's functioning at all. It is critical and essential to maintaining balance during activities of daily living. So all your patients, old, young, anywhere in between. Cervical motor control is really important to pretty much everything all of us are doing throughout each and every day. A couple things I did not know is that sensory inputs to the cervical motor control system originate from three areas. Proprioceptive, visual and vestibular systems. Makes sense, but just something I hadn't thought about in a while. And among those three systems, only proprioception directly interacts with mechanical axial loading, which also makes sense. But this is a big deal because as chirofractors we're constantly, I think, you know, looking at proprioceptive input, you know, gating pain through mechanoreceptive input. Proprioception, how are you moving in space? This certainly matters for those high level athletes or low level athletes that want to be mid level. Right. You know, many weekend warriors, it matters. And having great proprioception can make a big difference in performance no matter what level of performance somebody's at. So this is something that I think all of us should take note of. And proprioception itself is really dependent and interdependent on cervical flexibility. If you've listened to this podcast for a little while, you know, I talk a lot about the balance of strength and flexibility. You know, in my opinion, you know, chiropractic is a movement based profession that helps people maintain the best balance possible between strength and flexibility. If you have great strength and great flexibility, you're gonna be probably functioning pretty well. And proprioception is dependent upon that flexibility. Now, when flexibility is limited, mechanoreception is reduced, which it results in decreased proprioception. So these things start to become self perpetuating and self actualizing again. We feel limited flexibility. Mechanoreceptive input comes down and proprioceptive input goes down. And this can affect functional ability. It can impact performance, and it can impact, you know, maintaining balance. Not like somebody's necessary. In an extreme case, you might fall over, but it's not like somebody's gonna fall over. But maintaining that balance during activities of daily living in balance is, you know, critical to functional performance. So all of these things tie together. And when we're delivering an adjustment a little bit outside of what this study's gonna talk about today with axial load, but when we're delivering that adjustment and we're really just, you know, inundating somebody's neurosensory input system with mechanoreception, and that in turn can impact and affect proprioception and improve the flexibility, you know, the range of motion of that segment, that region, and ultimately whole body motion that matters. And it can impact daily living activities all the way up to. To high level athletic performance. So why is axial loading being brought into this equation? Well, axial loading is a risk factor for neck pain. How did they figure this out? They saw a whole bunch of aviators wearing headgear and people that carry sort of loads on their head, basically. And there is an increased rate of neck pain in those populations. Now you might say, well, I don't take care of a lot of aviators or people that carry a lot of heavy loads on their head in my practice, so let's make it more practical. Football, ice hockey, rugby, neck injury incidents, is high and primarily due to axial loading. I don't think you can watch a college football game or an NFL game at this point and not have, you know, a break on the field due to somebody leading with their helmet. They've tried to make all these rule changes. People, it's. It's a fast sport with big guys moving really fast. So there often is at least one time a game, once every other game, somebody that is, you know, taken out of the game due to a potential concussion due to an axial load. That happens when they lead with their head or somebody just got in an awkward position. Ice hockey, we see it a little bit less frequently, I'm going to say, than football and rugby, the same thing. So when we see these neck injuries that happen in sports, a lot of times it is due to axial loading. And neck pain itself is associated with decreased cervical range of motion. And I know there are differences between range of motion and flexibility. In a technical sense, I use them a little bit interchangeably. But the gist of it is neck pain, axial loading, decreased cervical range of motion, decreased mechanoreceptive input, decreased proprioception, decreased function and performance. I think you can see how all of these things kind of tie together. And we also know movements in the cervical spine are ridiculously complex. They're complex biomechanically, they're complex neurophysiologically. And there's a lot of, you know, whether it's the Z joints, whether it's the disc, whether it's the unclevertebral joints, there's coupled motion, there's uncoupled motion. There's a lot of, you know, three planes that are being moved in, and those can overlap as well. So there's a lot going on when somebody moves their cervical spine. And oversimplifying here, but, you know, it's like a lollipop. We got this head, you know, £11, whatever it might be, sitting on top of this little tiny stick, which is our cervical spine and our neck, and we're moving around and we're under gravity. We do things, car accidents, sports injuries, whatever it might be, that impact the structural function of what's going on with ligaments, what have you, based upon the injury itself. And that's a lot of action, right? That's a lot of action in the cervical spine. It's no surprise that hundreds of millions of people deal with cervical spine issues, cervical spine pain, and. And then you tap onto the fact that nowadays we're sitting in front of computers. We're sitting, you know, commuting to work, sitting in front of computers all day or over the last year and a half, we're sitting at home in, like, these cramped suboptimal conditions. You know, your patients are dealing with this all day, every day. And these are compounding factors that can result in pain, decreased performance, both, you know, you name it. So important stuff to keep in mind. Now, this study, they took 50 male participants, that's who they utilized. They checked out a couple things, what they called jpe, Joint position error was one of those. One of those items. And they were testing, okay, when we load the cervical spine, basically what happens when we give axial load. Now, axial loading resulted in decreased cervical range of motion in extension, but increased lateral flexion. Very interesting. That's not necessarily what I would have expected. But again, when they put axial load into the cervical spine, decrease in extension, increase in lateral flexion. Again, coupled uncoupled motion. In my opinion, another possible Explanation for the decreased cervical range of motion in extension with axial loading could be conscious and non conscious attempts to protect the cervical spine. So that's another interesting fact. When somebody gets into a loaded and extended position. I don't, I mean, I just think about it doing it myself right now and it's kind of uncomfortable. So there might be some conscious unconscious protection mechanisms going on at the same time. Now they also say additional axial loading could enhance this effect and supraspinal protective reflexes would inhibit extension via inhibitory sensory afference. Now, in contrast to the effects of axial loading on cervical extension, lateral inflection was increased with additional axial loading. Again, super interesting. I would not have expected that, but that's what they found. Joint position error was found to be increased with load irrespective of movement direction, albeit the increase reached significance with 2 kg of axial load. So joint position error result in this study could be explained by the sensory perception somatosensory system. Essentially, you know, somatosensory divided into vestibular, visual and somatosensory, excuse me, sensory perceptive system divided into vestibular, visual and somatosensory. So proprioception might be affected by additional weight because of cervical anatomic structures such as ligaments, joint capsules and muscles which contain a large number of, we can drum roll it, proprioceptors. Right. So proprioception might be impacted by that additional weight. They found joint position error. You start loading the cervical spine, you get over 2 kg of axial load and you start to have a lot of error in terms of joint position, understanding where you are in space. So cervical axial loading seems to trigger protective active and passive mechanisms, possibly causing decreased cervical extension range of motion and increase that lateral flexion. So what's the take home message? They say, quote, integrating higher axial loading into rehab or prevention exercises might be useful, especially if an individual should perform heavy physical work or endure axial spinal loading, such as personnel wearing headgear, rescue personnel, soldiers, high performance military aviators, or in populations using their heads to carry loads. So if you've never thought about axial loading during rehab or during prehab or during prevention maintenance wellness in your clinic gym, you might want to do so for certain populations. It's very clear at this point, axial loading, you know, can really change how we know where we are in space. Right. It can impact and influence our proprioceptive input, which can have a downstream effect of decreased performance. And when somebody gets into extension, if they are passively, actively, you know, sort of resisting that motion, you know that can be challenging if they're super into sports, if they're, you know, one of these individuals that's wearing headgear all day. So taking that into account and, and perhaps exploring axial loading of the cervical spine during your rehab exercises might be a great idea. I'd love to see a study like this. Now take it to the next level and get in there with spinal adjustment, spinal manipulation and see how that impacts as well, because, wow, you really do get a, you know, unscientific, I'll say blast, you know, of proprioceptive and mechanoreceptive input when an adjustment is delivered into your, to your patient. So I would be fascinated to see how that plays a role with all this. I think we'll continue to learn and discover more as time goes on, which is part of the fun of research, is that, you know, it's constantly uncovering new questions to be answered. And I think that's maybe where I've viewed research a little bit differently over the last year or two. Instead of looking for answers, I've looked at it more in terms of every paper stimulates new questions and continues that journey because finding a definitive answer in anything relative to health, because our bodies are so dynamic, is challenging at best. But understanding more and asking better questions, I think is continually a great step in the right direction. So that's the research for today. Hopefully there's some clinical pearls there for you and think about some axial loading with your patients specifically, if they're do that as a part of their job or for fun, I guess, as I guess I would say so a couple things to tidy up before we finish this episode. We are down to the end of the year. Happy New Year's, New Year's Eve, all that fun stuff to everybody. Thank you so much for tuning in. Over the course of whether this is your first week listening or whether you've been tuning in for years. Thank you so much. One big favor I would ask if you have not left us a review on Spotify, if you have not left us a review on itunes, please do so. That's what helps more and more docs find out about this podcast. So thank you so much for tuning in. If you'd be so kind as to take a moment and leave a review, I would greatly, greatly appreciate it. Also, couple things I want to ensure you know about before the end of the year comes one smart chiropractor. Our open enrollment period is wrapping up, so if you want to have more new patients, better retention and more reactivations next year, with we automate all of this process, coach you up along the way via social email, you name it, it is a full featured suite of tools for patient engagement, patient education. Head over to the smart chiropractor.com our open enrollment is wrapping up. Additionally, the Evidence Based Chiropractor building those relationships with other healthcare providers. We had a little bit of a launch open enrollment period which I very rarely do. Smart Evidence Based Chiropractor is always available, but it is available at a little bit of a decreased price right now. So it's if you are looking to build better relationships and have referrals come into your practice from other healthcare providers, head over to the evidencebasedchiropractor.com or you can shoot me a message. Jeff the evidence basedchiropractor.com and finally, if you're looking for your next career step, Chiro Matchmakers we have over 100 open positions paying $85,000 a year plus. That's just base alone. Check it out. There's a map. There's tons of positions. Florida, California, Midwest, northeast with over 100 active open positions throughout the United States and beyond. To be honest with there is probably something for you if you have been thinking about making a change. So get into the ecosystem over there. Chiromatchmakers.com have an awesome new year. Thank you so much for being a chiropractor. Thank you so much for tuning in and I will talk to you soon.

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