Ep 189: Training the brain for the chaos of sport, with Dr Meredith Chaput (part 1)

[00:00:04] Hello and welcome to JOSPT Insights, the podcast that aims to help you translate quality research to quality practice. I'm Claire Ardern, the Editor-in-Chief of the Journal of Orthopaedic and Sports Physical Therapy. It's great to have you listening today.

[00:00:22] Sports injury rehabilitation has moved well beyond simply focusing on physical function and recovery. There's various emphases on psychological responses to injury, mental readiness to return to sport, and now the visual cognitive components of recovery and return to sport.

[00:00:39] Here's where changes in the way that the nervous system works after injury, or neuroplasticity, can compensate for impairments like joint instability, pain and muscle inhibition.

[00:00:50] My guest today is Dr Meredith Chaput, a residency-trained, board-certified sports physical therapist and assistant professor of physical therapy at the University of Central Florida.

[00:01:00] Her research uses functional MRI to evaluate neuroplasticity after knee injuries, focusing on understanding how people use visual attention to compensate for motor control and how rehabilitation might better target these compensations.

[00:01:16] In part 1 of this two-part chat, Meredith introduces the visual cognitive control chaos continuum as a framework for sports injury rehabilitation.

[00:01:26] Okay, let's get started.

[00:01:29] Dr Meredith Chaput, welcome to JOSPT Insights.

[00:01:33] Thank you for having me today.

[00:01:34] I'm really excited to talk about this topic.

[00:01:36] I am very excited to hear about this topic from you, Meredith.

[00:01:40] We have lots of enthusiasm and lots of people asking me for more on the control chaos continuum, which is what we're going to talk a bit about today.

[00:01:48] We're talking more broadly, I think, about the central nervous system, plasticity and how to harness those changes for good during sports injury rehab.

[00:01:58] And the sports injury we're focusing on today is an ACL injury and reconstruction.

[00:02:03] Although I suspect probably the principles we're going to talk through today can apply to other sports injuries.

[00:02:10] Meredith, let's start with what happens in the brain and the nervous system after an ACL injury and reconstruction.

[00:02:17] What's specific to the chaos continuum and what my area of research mainly focuses on is what we call cross-modal plasticity.

[00:02:28] And so this is brain changes in regions of the brain that are responsible for integrating multiple sensations for motor control.

[00:02:41] So if you think about trying to pick up like a water bottle that might be next to on the table, you often use vision to visualize the object and then proprioception from your hand to reach for it.

[00:02:53] And then those two signals tie together to produce smooth arm movement to it.

[00:02:58] But if you close your eyes, as you reach for the bottle, your arm trajectory is a little bit different.

[00:03:04] The path is a little bit slower.

[00:03:06] And so this involves your cerebellum.

[00:03:10] It involves basal ganglia.

[00:03:11] It involves many resources, but specific to sensations of vision and proprioception.

[00:03:16] Those are the regions that we're talking about, and we call them cross-modal regions.

[00:03:19] After ACL reconstruction, we see when individuals return to sport, these regions that particularly tie together vision and proprioception are elevated compared to healthy controls.

[00:03:33] I think the general commentary around this is we assume individuals become more visual reliant, but really it's more of visual and cognitive reliance because these regions are driven by attention.

[00:03:52] So without tying in that attention piece to our rehabilitation, we sort of miss targeting these aspects of the brain changes or neuroplasticity after ACL injury.

[00:04:04] That's so fascinating.

[00:04:06] Can you talk a little bit more about the attention part of this?

[00:04:10] How does attention come into this sort of cross-modal changes that you're talking about?

[00:04:15] The attentional networks, basically, like the frontal parietal network is one example and one that we wrote about in the chaos commentary actually.

[00:04:26] Functionally is connected with these other regions.

[00:04:29] That means that when the frontal parietal or attention network activates, it is in sequence sort of at the same time as these other regions.

[00:04:38] And cognition is very powerful.

[00:04:42] Whereas if I tell you to attend to something, you can miss other relevant important information.

[00:04:50] And so there's sort of like these classic examples of this on YouTube.

[00:04:53] If you just Google like a visual attention test where you'll have like basketball players that are in like white shirts and maybe like black shirts.

[00:05:04] And the prompt will tell you to only look at the players in white and count the number of passes that they make.

[00:05:11] And you're, they're all moving around.

[00:05:13] Both teams are moving around passing the ball.

[00:05:16] And then all of a sudden there'll be like a bear or something, somebody in a costume that walks through the middle of the screen and you miss it.

[00:05:22] But you accurately count the number of passes.

[00:05:25] That's because you've just used attention to directly tune into the sensation or, you know, the visual stimuli that you want to attend to.

[00:05:34] And so you miss what might be relevant information because of it.

[00:05:38] And we do this in rehab all the time where we tell somebody to attend to their body movements.

[00:05:45] But if there was an external stimuli, like in sport, like an opponent or a teammate, that's where their attention has to be.

[00:05:52] It can't be on their body movements.

[00:05:54] So that's more of a similar, I guess, a clinical translation of attention from brain plasticity.

[00:06:01] So cool.

[00:06:02] And I do remember seeing some of those examples on YouTube and you think, oh, you couldn't possibly miss that bear or that whatever that thing is.

[00:06:11] And then you go and do the test and you think, oh my goodness, I really did miss it.

[00:06:15] I was so focused on something else.

[00:06:16] Absolutely.

[00:06:17] That's just a very quick demonstration of just like how powerful attention is and why I think we can use like dual tasks in this framework in rehabilitation to help readjust it.

[00:06:29] So then where do our current approaches to rehabilitation after ACL injury fall down in your view?

[00:06:37] What are these programs typically missing?

[00:06:40] Typically, our rehabilitation is so motor focused.

[00:06:44] And I think this is both rehabilitation, but also like sports performance is all of our outcomes that we measure are based off of physical performance,

[00:06:55] whether that's muscle strength, power, hop distance, you know, jump height, biomechanics.

[00:07:03] They're all physical movement performance focused.

[00:07:07] But in sport, honestly, most sports that have high prevalence of ACL injuries, you work at sort of this like the maximal neural resiliency level.

[00:07:19] You have spurts of this max performance, but that's what we're quantifying every individual off of.

[00:07:26] And what I think we're missing in our return to sport tests and even in interventions is this visual cognitive component.

[00:07:34] Because the sports that have high prevalence of ACL injuries, they usually occur during some sort of neurocognitive, high neurocognitive demand that then induces what we call like a sensory motor prediction error.

[00:07:50] Or your perceived sensory stimuli and environment doesn't match what is actually occurring.

[00:07:58] So then you have to recreate a new motor for a plan.

[00:08:02] And I don't think our rehabilitation replicates that environment really well, starting from a very early stage.

[00:08:10] Because honestly, there's so much to focus on from a returning range of motion perspective, quad activation, and then progressing physically.

[00:08:20] That I think it's just easier to do all of those things first.

[00:08:26] And then at end stage, get to the dual task when they've already figured out all the physical stuff, right?

[00:08:32] Then it's easier for me to implement more of those elements.

[00:08:35] And so that's usually the typical progression that you see.

[00:08:39] But neurologically, I think waiting until the end is too late.

[00:08:44] From a typical rehab perspective, it would be great if we can start to implement some of those elements very early on.

[00:08:51] Meredith, you used the term neuroresilience.

[00:08:55] What does that mean?

[00:08:57] Adaptability of your nervous system.

[00:08:59] So in the term or in the phrase of like sensory motor prediction errors or that mismatch that I talked about, it's your ability to handle those mismatches.

[00:09:09] A lot of your ability, this goes back to motor learning, is just exposure to them.

[00:09:14] So if never exposed to the load, you're not going to be able to handle it physically.

[00:09:18] I view the same thing neurologically.

[00:09:20] If you're not exposed to the load over the course of, you know, six months, and now you're expected to return to sport, that's going to be really difficult.

[00:09:29] Now, the other thing I want to pick up before we get stuck into visual cognitive control chaos continuum is a comment I made right at the start of the podcast.

[00:09:38] And that was about suspecting these principles might apply to other sports injuries than ACL.

[00:09:45] Are these principles or are these very specific to an injury type?

[00:09:49] I think they are very broad, actually.

[00:09:51] So a lot of this research that has informed the commentary and has informed this area of research actually is much more developed in aging.

[00:10:03] And individuals with mild cognitive impairment, I would say we're a good maybe 20 years behind.

[00:10:09] I think from a musculoskeletal injury perspective, it transfers to any musculoskeletal injury because all of it is involved with neural consequence, whether that is a hamstring strain.

[00:10:23] There's decent literature now emerging with lateral ankle sprain, looking at neurocognitive recovery and also neurologic brain activation sort of recovery.

[00:10:32] And then also it's starting to come into play in like shoulder rehabilitation.

[00:10:36] I think another good tie-in is concussion and management of concussion.

[00:10:40] So we know that if you had a concussion, you're at much higher risk of lower extremity injury.

[00:10:45] And so understanding the relationship between those through a neurocognitive or visual cognitive lens, I think is very important.

[00:10:54] For sure.

[00:10:55] And I like this idea of principles that you can take from and apply in the clinical context where you are.

[00:11:02] Let's pick up this idea of the control chaos continuum.

[00:11:06] What is the control chaos continuum, Meredith?

[00:11:09] And why was it important to add a visual cognitive progression to the original control chaos continuum?

[00:11:17] So the control chaos continuum was developed by Dr. Matt Tabiner.

[00:11:21] I actually read it just as I was starting my PhD, I think, around the first version of it came out.

[00:11:29] The original purpose was basically to bridge the gap between rehab and performance for on-pitch rehabilitation.

[00:11:37] And so it progresses all aspects of physical performance through five stages of chaos to then return to performance.

[00:11:46] Keeping in mind that in order to return to performance means that you have really high cognitive demand.

[00:11:54] I had just read a few articles by like Buzz Swanick and co.

[00:12:00] And I was like, oh, cognitive processing might be important for ACL injury.

[00:12:05] So I went to my PhD advisor, Dustin Grooms, like probably three weeks into my PhD.

[00:12:13] And I was like, this is a really cool continuum.

[00:12:16] Like, what do you think about adding cognition into this?

[00:12:19] And he said to me, he said, sound great.

[00:12:21] Figure out how to do it.

[00:12:23] And so that started the four-year journey of working with Matt to figure out how can we bridge this gap.

[00:12:29] And originally it started with like the performance spectrum where like, okay, we can add these element end stage to help bridge the gap.

[00:12:40] But then as I grew through my PhD, I realized like these changes in the brain likely occur over time.

[00:12:48] And that we probably as rehab practitioners have a lot of like influence in that progression.

[00:12:54] And as I began to appreciate that, it sort of transformed to, okay, we probably need to do this earlier.

[00:13:02] And so that's how we decided to plug it into acute rehab based off of some of the preliminary brain data that we had from Dustin's work.

[00:13:11] I felt that as a clinician, there was a handful of commentaries that came out on neurocognition, but nothing gave me a framework.

[00:13:20] And that was the number one thing that I always got asked was like, how?

[00:13:24] And there was yet to be something that provided a clear neurophysiologic basis for progression to target the nervous system or different avenues of visual attention and attention in general.

[00:13:40] A lot of the tasks that were out there were what I would call district divided attention paradigms where it's just a simple dual task where you're literally doing maybe a squat and serial seven subtraction.

[00:13:54] But my whole premise was that's great.

[00:13:57] That's a good, that's a decent dual task, but is it targeting the neural reason why?

[00:14:02] And I was becoming, I think, frustrated as a clinician and like young clinical scientist in the implementation.

[00:14:12] And so I really wanted to develop something that could easily be implemented, but had the neural foundation of why.

[00:14:21] That's such a wonderful insight into the work that goes into, into something like this, Meredith.

[00:14:28] You didn't just wake up one day and think, oh, I might write a paper about this.

[00:14:31] It's a four year process of thinking, working through the underpinning, pulling from different research areas, from different clinical areas, as you say, from aging and mild cognitive impairment and thinking about how those are principles of the brain and plasticity also apply to a very different context in sports injury rehabilitation.

[00:14:51] And I'm really grateful for this work for so many reasons.

[00:14:55] Number one, probably that I, in physio school, like probably many listeners, didn't get much about neurocognition.

[00:15:03] Of course, we all learn about neuroanatomy and we learn about control of moving and we learn about motor control theory, probably.

[00:15:12] But there's not really that bridge from the theory of it to actually what does that mean in clinical practice?

[00:15:18] And what does that mean for me as a sports or an orthopedics clinician?

[00:15:22] And that's part of what I really love about the work that you've been doing, you and others in the team, is to try to bridge that gap.

[00:15:30] So let's talk a little bit about the how and maybe the underpinnings as well of what does that look like and how would one approach it in clinical practice?

[00:15:40] I guess maybe let's start with what does the visual cognitive control chaos continuum do for clinicians and for the athletes they're working with?

[00:15:51] The idea of the progression is, like I said, to start very early.

[00:15:58] And so an example I always like to give is maybe like post-op week one or two, right?

[00:16:07] Your patient comes into rehabilitation, you're starting with quad sets, straight leg raises, NMES.

[00:16:14] If you're practicing at a very high level, they shouldn't have to attend to the stimuli because it's already contracting for them.

[00:16:23] So from that very small or like acute stage, I'm teaching individuals to attend to their knee joint and to attend to muscle contraction to promote motor control.

[00:16:36] That's where like stage one comes in of high control.

[00:16:40] That is just like the patient understands like the foundation of the physical control that they're supposed to be doing.

[00:16:47] Something that we try to emphasize throughout the paper is that like for motor learning and for like improving motor control, things can't be 100% errorless.

[00:16:56] I think as clinicians, we have the patient's best interest in our heart where we want them to be perfect.

[00:17:04] And it hurts us to allow them to struggle a little bit and really they need to.

[00:17:11] So the idea is that you have this like five stage progression of visual cognitive challenges that progresses from divided attention to like high level selective visual attention mechanisms.

[00:17:25] And basically you are like able to induce error of about 30% following the continuum.

[00:17:33] So as a clinician, and if I'm going to implement this in, let's say one rehab setting or one rehab like treatment, let's say,

[00:17:42] I might in anywhere use three or four different stages for different interventions.

[00:17:48] So typically in like motor learning, we might say everybody is in this one, you're in the cognitive phase of motor learning.

[00:17:56] But the way I would like this continuum to be implemented, and I think our team would like this continuum to be implemented,

[00:18:02] is that based off of whatever intervention you're doing, you might be at a different stage of the control chaos continuum.

[00:18:10] So for a quad set with NMES, you might be able to do something that's at phase four or five.

[00:18:16] But if you're doing a squat and it's the first time that they've squatted, you might be at high control or control greater than chaos phases of the continuum.

[00:18:27] So instead of lumping every intervention into the same phase, it allows you both a cognitive progression when clinicians are very well versed on physical progressions.

[00:18:40] So then it allows you to layer easily, especially in acute phases of rehab.

[00:18:45] You are chronically, physically underloading individuals because they have quadriceps muscle inhibition.

[00:18:54] They have all of these like neurologic consequences, like the biology of healing.

[00:18:58] You have to respect that throughout your rehab.

[00:19:01] And so if you are physically underloading them, but then you're allowing this neurologic compensation, what's the benefit of that?

[00:19:10] Whereas if I'm physically underloading them, I can cognitively load them to make that task harder.

[00:19:15] It doesn't always have to be a physical progression if biologically they're not ready to progress.

[00:19:22] I love that flexibility, Meredith.

[00:19:24] And it really opens up so many different opportunities to say, okay, biologically, I need to stay at this lower level of physical loading.

[00:19:34] But as you say, you can then layer on top of that a lot more cognitive load, if you like, to make that much harder.

[00:19:41] Can you share a couple of examples of what that might look like?

[00:19:43] How would you balance the physical load with the cognitive load and change those things up?

[00:19:49] We get from a performance perspective, very in tune with physical progression.

[00:19:55] Your focus of your training session is hypertrophy max strength.

[00:20:00] Then go ahead and do that.

[00:20:01] I'm not saying that we need to add a cognitive challenge onto that.

[00:20:05] But in phases where it is more, I would say, submaximal efforts, like in acute rehab and especially in transition to dynamic tasks, a very simple, you could use like a forward lunge, let's say.

[00:20:22] And for high control or for phase one, you might have somebody just like lunge to a target at their own pace.

[00:20:29] In phase two, you would then layer on like a very simple working memory task where they just basically follow directions.

[00:20:41] So this could be a PowerPoint screen where the cones are colored and they just lunge to the color cone.

[00:20:48] This could be actually you pointing in a direction in the clinic where you're pointing right, left or forward based off of what cone you want them to lunge to.

[00:20:59] And then phase two might be or phase three, excuse me, might be adding like a simple decision into it.

[00:21:06] So an example that I think we use in the videos is either doing a lunge or like a submaximal jump.

[00:21:14] So now you hold up fingers or you hold up flashcards or a PowerPoint screen and it has math problems on it.

[00:21:22] So if the answer is odd, they have to do a lunge or if the answer is even, they have to do a squat or a jump.

[00:21:29] So then it just adds one more layer of complexity where they have to now decide between two physical tasks that are predetermined.

[00:21:37] The following stage after that now involves like inhibition.

[00:21:42] And so all of the movements are still predetermined where they're either going to do like a lunge or a jump.

[00:21:48] And now you might add either a noise or a color that is inhibition.

[00:21:53] So I think in an example, we use like orange as an inhibition color where they're still solving the same math problems.

[00:22:00] The movements are still predetermined.

[00:22:02] And now if something pops up that's orange on the screen behind the math problem, then as a rest, you don't have to do the task there.

[00:22:09] And then the last phase would be what I would say chaotic.

[00:22:13] And that's where you can add visual perturbation, manual perturbation.

[00:22:17] You could add auditory stimuli.

[00:22:19] So something that would draw attention away from the physical tasks, such as, you know, having to change direction.

[00:22:29] Or I think of it similar as like a coach calling a different play, like in the middle of like what you're trying to do, something like that.

[00:22:36] That's like not necessarily a visual stimuli.

[00:22:38] But still causes like chaos in whatever you're trying to do.

[00:22:42] So that's like a, I would say like a low level to like intermediate progression.

[00:22:48] And then you can also scale that based off of whatever technology you have.

[00:22:51] So I'm very passionate about making everything like as clinically applicable as possible.

[00:22:57] So like PowerPoints, tablets, fingers and flashcards are like always in the clinic or you can get them easily.

[00:23:07] But if you have access to some of these higher technology things like Blaze pods or vector balls or whatever, I support none of them.

[00:23:15] But if you have access to these other.

[00:23:17] This podcast is not sponsored by any of those companies.

[00:23:21] If you use any of those products or you have access to them, that's great.

[00:23:25] Virtual reality.

[00:23:25] That's great.

[00:23:26] But I like to operate under the definition that like we don't have those things available to us.

[00:23:33] I love the really basic clinical application and without so much technology.

[00:23:41] I think we've talked about what sort of tech you need as a very basic starting point.

[00:23:46] If you've got a pretty Spartan existence in your clinic, there's actually, there's a lot you can do with your own laptop and a PowerPoint slide and the laptop screen, a tablet screen.

[00:23:56] Or if you're fortunate to have a slightly larger screen that you can project onto in the clinic.

[00:24:02] Wonderful.

[00:24:03] If you have a bit more money, what's the sort of thing that you would encourage people to invest in?

[00:24:09] I would say stroboscopic glasses are very good for like visual perturbation.

[00:24:14] And I think visual perturbation is something that can go a long way.

[00:24:20] And those are meant to be used with external stimuli.

[00:24:24] So I think visual perturbation sort of glasses and even using preliminary like some virtual reality can help because it takes away your visual compensation.

[00:24:36] But you can use virtual reality for so many things, honestly, for motor imagery type work.

[00:24:44] There's a lot of besides cognitive challenges that can be displayed in them or used simultaneously.

[00:24:51] I'm a huge fan of reaction sensors of any type, whatever you prefer.

[00:24:58] That's like programable, because I think that steps into return to play testing.

[00:25:03] And having something where you're able to, your clinic can program like sequences, I think is important.

[00:25:11] So we use Fitlight in our research lab here.

[00:25:14] And that's mainly because I can get really good reaction time from them.

[00:25:18] And they're reliable from a research perspective.

[00:25:21] If you don't have the capacity to program those and whatnot, I think blaze pods are like a really good alternative.

[00:25:28] I would say that I'm most passionate about understanding the why and that understanding that you can do all of this with very low technology.

[00:25:39] And that the sequence is really important, I think, about like how you're applying the dual tasks.

[00:25:45] I think we get really excited about technology.

[00:25:47] And then we just like throw the whole gamut of things at people.

[00:25:52] And I don't know that that's the solution.

[00:25:54] So I would actually advocate for like save your clinic money and like do more work to try and implement with low technology first.

[00:26:02] Figure out what works best for you and then implement with higher technology.

[00:26:07] Love it.

[00:26:08] I love it, Meredith.

[00:26:08] And maybe we can put a plug in for if you're saving your money on the tech, you might invest it in a neuromuscular electrical stimulation machine or some other piece of equipment.

[00:26:19] Yes.

[00:26:19] Stim the quads.

[00:26:22] Thanks for joining us for part one of this two-part chat.

[00:26:25] Check out the show notes for links to more information on the visual cognitive control chaos continuum.

[00:26:31] And join us next week as Dr. Chaput explains how to progress visual cognitive training in your sports injury rehabilitation.

[00:26:42] Thanks for listening to this episode of JOSPT Insights.

[00:26:45] For more discussion of the issues in musculoskeletal rehabilitation that are relevant to your practice, subscribe to JOSPT Insights on Apple Podcasts, Spotify, TuneIn, Stitcher, Google or your favourite podcast app.

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