In this video, we are providing an excerpt from our Essentials of Elite Performance course that outlines the primary sensory inputs that influence movement, and the possible consequences of sensory mismatch. While we definitely go into more detail on these topics throughout the Z-Health curriculum, this foundational framework will help guide your thinking and your client programming for the rest of your career!
Now, whenever we talk about this concept of prediction, this moves us into discussing what we call the neural hierarchy. And you can see basically, at the beginning stages of all this, we just talk about three major systems. And the way that we describe this to clients, is we will usually use the concept of GPS. So everyone’s familiar with GPS at this point, years ago, you know, you had the unit that sat on the dashboard of your car, or whatever. And I usually will ask people, do you know how GPS works? And most people go, well kind of, there’s a computer and it talks to a satellite, and it tells me where we are? Well, it doesn’t work just with one. The way GPS typically works is, we need a minimum of three satellite for the central computer to be able to access in order to triangulate our actual position. Most modern GPS actually use more than three satellites, but we need a minimum of three to know where we are? So we find this to be a great analogy, for how the human body functions? So for us, the central computer, the actual GPS unit in the human body would be the brain. And when we think about the three satellite systems; We’re going to talk about the visual, the vestibular, and the proprioceptive. Now, the reason that this is listed out and looks this way is that when we talk about the hierarchy, we give weighting to different systems.
If you remember in the visual section, we talked about the idea that four primates for humans, the visual system is the dominant sensory system. More areas of the neocortex are devoted to processing visual signals than anything else. And so in the hierarchy, we tend to consider the visual system as priority number one. From there, we next have the vestibular system. The vestibular system obviously is, as we’re going to discuss in a minute. And as I mentioned previously. It’s the inner ear, has five sensors per side, and it has an enormous impact on multiple functional systems. It’s going to allow us to really locate ourselves in space. And then finally we have the proprioceptive system. Now, why this is super important for us, even at the Essentials level to convey is that most of our classical education is around improving the proprioceptive system. And I keep mentioning this, right. We work on movement and we do a lot of mechanoreceptor based work. As we mobilize people, we have them move, we tape we ice, et cetera. That’s great. But what you need to understand is that in the hierarchy, the proprioceptive system will almost always be the system that is forced to adapt to problems that are occurring higher in the hierarchy.
So, as an example, when I first was, I mentioned this in one of the earlier sections. My first experience with the client, with chronic neck pain, changing her glasses and her neck pain going away. So think about clients in you have. And if I, I usually do this whenever we have group classes, everyone is in here. I say, Hey, I want everyone to assume the posture of your typical client. And usually about 70% of the class will go, right? And they go into that, anterior head carriage, thoracic hyperkyphosis, rounded shoulder position, that so many of us adopt over time sitting at the computer, et cetera. So at that point, we then start to talk about that because if someone comes to you and they have anterior head carriage, they’re hyperkyphotic. And if we only use a proprioceptive approach without ever evaluating their visual system, their vestibular system, we are probably going to struggle to make any type of long term change. Because the proprioceptive system usually is the system that pays the price for higher order deficits. So if I have someone that’s sitting at a computer, eight to 10 hours a day, and they have visual deficits, as their eyes are fresh in the morning, hopefully they’ve slept well. They wake up, they will have a maybe reasonable level of acuity, right? So if we go back to the Snellen chart, maybe they’re 20-20 at 7:00 AM, when they wake up. If you test people throughout the day, probably by nine or 10, they will have moved from 20-20, to maybe 20-25, maybe in one eye. So now I have maybe 20-20 in my right eye, 20-25 or 20-30 in my left eye. This eye is getting a little more blurry. So now my ability to move my eyes around on the screen, focus on what I’m seeing and understand it is beginning to be, is becoming more difficult, because now I have a blurry camera lens, and a clear camera lens. So at that point, what we may see is a slight rotation of the cervical spine to bring the better eye closer to what the client’s trying to see on the screen.
Now we test them maybe at two o’clock, and their eyes are getting really tired, really fatigued, because they’ve been on the computer all day. So now maybe they’re 20-40 in the left eye, 20-30 in the right eye. So their acuity is getting worse, because they’re developing visual fatigue. So now, head-turning is not solving the problem. So now, they’re going to begin moving the head closer to the screen, adjusting the lighting conditions, et cetera, all in an effort to use their dominant sense in the way that they need to. That person then shows up for training, or they show up in your therapy clinic or wherever. And what are they complaining about? And you’re like, well, my shoulders are killing me all the time. I have neck pain. And as you see them, they have a little bit of an anterior head carriage. Maybe they have a little rotation and a head tilt. The proprioceptive approach would be to go in and start palpating the trapezius, and the paraspinals, and then maybe testing deep neck flexors, mobilizing the cervical spine, giving them a lot of mobility drills. And all of that may be beneficial. It may help their pain. It may help their muscle tension, but what may never do is solve the problem, because we have ignored the higher order deficit. So when we talk about all this stuff, as I said, the goal here is for you to leave this particular course with a broadened view of the multiple systems involved in high quality movement so that you can assess and train your clients more efficiently.
So three systems we have for prediction, obviously, as I said, we have the visual, vestibular, and proprioceptive. This is the hierarchy. And we would prefer for you to learn it in this order. There are times when we will say maybe it switches a little bit based off a individual presentation but for us, it’s really important that you learn it in this order. All right. So whenever we talk about this, we’re going to now start using a term called “Sensory Matching.” Because in order for us to move efficiently through the world, we need our brain to receive information from our three major satellite systems. And there are a couple of requirements for all this to work well. So number one, we need clear information from all three systems. So I need my visual system to give me similar information, to my vestibular system. And I need those two systems to match up with what I’m feeling proprioceptive. All right. So I need clear information from the three systems. This is where it gets really interesting, because again, we have two eyes, we have two sets of vestibular organs. We have obviously huge number of muscles and joints, and et cetera. So the idea of having clear information from all three systems means that as a movement coach, I need to be able to test each system, and each side of the system independently. I need to also make sure that they are working together. And then I need to make sure that they’re integrating with the other systems. So over time I have to test the right eye, I have to test the left eye. Make sure that the left eye and right eye are working well independently, and then working together. I have to test the right vestibular system, left vestibular system, and make sure that they are talking to one another well in integrating and saying the same thing. And then I have to look at the right side of the body, the left side of the body, the midline, the right side and left side of the body, make sure that those are functioning well. And that those are also integrating with what we’re receiving from the visual and vestibular systems. So accurate prediction is honestly a miracle, right? At some level. The fact that we can move well through the world with all these different things going on, I think is one of the coolest things. But it also means that there are lot of possible areas for things to go wrong, that we need to be able to test. All right.
So we need clear information from our three satellite systems. That’s number one. And then number two, we now have to remember that the brain needs to be able to integrate that information appropriately as well. So it’s not enough to just test the eyes. We have to make sure that the brain knows what the eyes are saying. It’s not enough to test the vestibular system, the proprioceptive system. We have to make sure that the brain is healthy enough, to integrate that information, make a decision about it, and then create an appropriate motor output. All of this is tied up into the assessments and exercises, et cetera, that we teach throughout the curriculum. Well, we want to make sure that you understand this particular concept, because it helps shape everything that you’re going to do with a client. Safety begins with accurate prediction. Accurate prediction comes from clear information, from our major neuro hierarchical systems, and the ability of the brain to correctly integrate that information. So it starts to show you why there are so many different areas of applied neuroscience that are so interesting, and are often so effective in creating change. Now, when we have problems with sensory matching, we just call it sensory mismatch. So now instead of having our satellites, we’ve got a, you know, we’re in Vegas here. So, we have a slot machine that’s gone badly wrong, right? We didn’t win anything on this one. So now all of a sudden I’m getting information from one of the systems, or all the systems. Or my brain’s not integrating the information correctly, or all of that’s going on.
So let’s say I have a visual problem. I have a vestibular problem. I have proprioceptive problems. And I’ve had a brain injury, which makes integration difficult. We call this process of inappropriate information, or inappropriate integration from each of the systems coming into the brain, sensory mismatch. The most common example of sensory mismatch that everyone is familiar with at some level, is motion sickness. So what is motion sickness, right? You’re riding in the car, you’re on a boat, and what’s happening is your visual system is receiving one type of information. Your vestibular system is receiving a different type of information. And because the brain is experiencing this mismatch, you get symptoms, right? The brain wants you to stop what’s going on, and wants you to change behavior. So then it will typically enact one of its most useful tools for getting you out of a moving, you know, object, which is nausea and vomiting. So right. You’re on a boat. Maybe you’ve not been on a boat, and you go down, you’re sitting in the cabin, and you’re getting the vestibular sensation of movement. The boat’s going up and down, it’s rocking side to side, but maybe you’re sitting there reading. And because your brain’s so good at stabilizing your eyes, it feels like you’re not moving visually, but your vestibular system’s getting this constant sense of up and down and side to side motion. And if that goes on long enough, all of a sudden your brain says, wait, I’m not sure what’s actually happening. I’m getting different information from my eyes. As I compare it to my vestibular system, I don’t like this, I want you to stop. I need you to get off this boat, or at least need you to stop reading. And the motion sickness starts to occur. So that’s a classic example of sensory mismatch. Another example that we often will talk about. If, you come from a biomechanical background, obviously, people been talking about fascia for 15 or 20 years. And if you’ve done a lot of hands on work with people, you’ll find examples, or you will have seen, or felt people that feel twisted, right? They feel rotated. They have thoracic rotation, cervical rotations. Once again, this is a classic example, often of sensory mismatch. So we were talking earlier about this example of a client that comes in. They work at a computer all day, and they have a very different level of acuity in each eye. So let’s take that to its logical conclusion. So you can understand what we’re talking about with sensory mismatch, and how the proprioceptive system may pay the price. So let’s say you have a client that comes in, they’re 45 years old, and we’re going to imagine that their eyes are even worse than we thought. All right. So they have maybe 20-50 vision in the left eye, and 20-20 vision in the right eye. Meaning the right eye nice and clear. The left eye is not very good. The typical instinctual response to this is to use the better visual side, to explore or work in the environment. So if my right eye is my dominant eye, usually what will happen? Dominant eye and more sorry, eye with more acuity. We will typically see people do this. They will actually rotate the head to bring the better eye toward the midline of the body, because it will allow them to both use foveal vision, and access more peripheral vision. So we have a little bit of a left head rotation to bring that right eye to the midline. Okay. So that’s number one. Now let’s add a vestibular problem to that. All right. Say that again. We’re going to add a vestibular problem to that.
So let’s imagine that this person, maybe they fell and hit their head a couple of years ago. It was mild, they were dizzy for a couple of days, but thought nothing of it really, they were checked out and now they have a underlying low grade vestibular problem. We haven’t talked about the vestibular system a lot yet, but we’re going to, but what I want you to know right now is that we have these different canals in the inner ear. And some of those canals are dedicated to telling the brain, if I’m turning my head right, or turning my head left, right? In other words, they’re going to handle horizontal movements. So now let’s say we’ve got this person, they have this right head rotation. And let’s say their vestibular injury has altered the firing rates, and firing patterns in their inner ear. And the altered firing rates are actually indicating to the brain that their head is turning right. So now we have a left head rotation, to bring my dominant eye online. But now my inner ear is actually telling me that I am turning my head right. And this is a common issue. All right. So I now have competitive stimuli occurring. I have a visual stimulus saying, I want you to keep your head turned left. I have a vestibular stimulus that’s telling me, I’m constantly turning my head right. So now I have a tug of war going on between the visual and vestibular systems. Guess who’s going to pay the price? The proprioceptive system. Imagine the amount of tension that’s going to build up as a result of that sensory mismatch. I will have ongoing neck, shoulder, thoracic, full body tension, actually. And if that goes on free years, the proprioceptive system will do its best to adjust for those tensions, and start to alter fascial tensions, and even fascial structures over time. So sensory mismatch is not just a, Hey temporary. I got car sick. It can have long term ramifications on the musculoskeletal system.
Other example, where we see sensory mismatch in at least a literature, scoliosis, a high number of patients with scoliosis, also have on-testing, significant vestibular disorders. It’s not completely consistent. We cannot say 100% of people with scoliosis have detectable vestibular disorders, but it is a relatively high percentage, depending on what age groups you look at? Sensory mismatch, obviously we’ve been talking about pain throughout. So you would expect that to be a potential ramification of the mismatch. Neuro behavioral disorders. Another interesting side of all of this. And remember, when we talk about research, sometimes we can correlate findings. We can’t say definitively if X causes Y, but we can see that they’re associated. There is a lot of research looking at sensory mismatch. So visuals, vestibular, and proprioceptive mismatch in both children and adults with neuro behavioral disorders.