Sport-Related Concussion and Lower Extremity Injury

Sport-Related Concussion and Lower Extremity Injury

In this blog, I will be discussing the primary research I am conducting for my PhD studies at the University of Nevada, Las Vegas.  It has been a bit since I last posted, so I figured it would be best to provide an update of what I have been doing all semester, so I hope you enjoy!  (One caveat, I’m not going to reference any literature in this piece, this will be based strictly off my knowledge of the current research.  I recently submitted a literature review on this topic for peer-review with the expectation of publication in the near future.  I will certainly share this heavily referenced text once that process is complete).  Before I get into the nitty gritty of this post, I’d like to start with a cliff notes version of the crux of my dissertation research, which will be followed by a more in-depth analysis.

Sport-related concussions (SRCs) are now classified as a major public health crisis affecting athletes across all major sporting levels.  Injury surveillance data has recently determined that compared to their non-concussed counterparts, athletes who sustain a SRC are at greater risk for lower extremity injury well beyond the resolution of traditional SRC assessment batteries.  This may in part be attributed to subtle cognitive and neuromuscular deficits that are exposed during dynamic sporting tasks.  However, the current literature has yet to elucidate the biomechanical movement patterns of sport-specific activities (i.e. jump-landing) post-SRC.  Examination of lower extremity biomechanics after a concussive event may offer objective analysis to provide a rationale for the association between SRC and lower extremity injury risk.  Therefore, the purpose of my research is to examine jump-landing biomechanics in adolescent and collegiate athletes with and without a history of SRC.

Our knowledge of SRCs have come a long way in the past few decades.  Initially viewed as a lack of “mental toughness”, we are now starting to understand the short- and long-term ramifications of this injury.  Millions of athletes per year will sustain a SRC across all sporting levels.  While (US) football receives most of the media attention, sports such as soccer, ice hockey, and lacrosse also pose significant risk for a concussive injury.  While the risk of subsequent SRCs are significantly (up to 6x) higher following a first concussive event, what many do not know is that these same athletes are at a much greater risk for a lower extremity injury (i.e., anterior cruciate ligament (ACL) tears, ankle sprains, hamstring strains, etc.) for reasons that are largely unknown at this point.  Specially, concussed athletes across sporting levels (high school, collegiate, and professional) are at an approximately 1.5 – 4 times greater risk for the aforementioned injuries when compared to athletes who have not sustained a SRC.  But here’s where it gets really interesting: The risk of lower extremity injuries post-SRC extends well beyond the resolution of traditional SRC reporting measures – in some cases up to a year after the initial concussive event.  In order to best understand the SRC complexity, practitioners must first understand the common assessment batteries administered following such an event.  Following this, I discuss why these measures may lack the precision to adequately detect an at-risk athlete for further injury, particularly to the lower extremity.

The three most common ways to assess a SRC are as follows: symptom reporting, neurocognitive evaluation, and balance / sway measures.  However, there are issues with all three in terms of returning an athlete back to the field.  Bearing in mind that I value all of these tools as part of a multifactorial approach to SRC assessment, it is my goal to develop methods in conjunction with these tools to mitigate further injury after a SRC. Let’s discuss.

Symptom Reporting: With symptom reporting, many athletes (especially adolescents) are unaware of the most common signs following a sustained SRC.  There have been numerous studies published on the lack of SRC knowledge at the youth level and it continues to be a big problem (If interested, I can provide a few posters from the CDC HEADS UP program to share with your team!).  Another issue is that some athletes will attempt to hide their symptoms in order to stay on the field, there’s a reason why approximately 50% of all SRC are believed to go unreported.  This is typically the case in male contact sports, as the literature indicates that female athletes are much more likely to report a suspected SRC.  What we must understand is that not every SRC is obvious.  Some athletes will experience a headache that can be easily passed off as just the nature of contact sports.  Others will demonstrate obvious signs such as postural imbalances, dizziness, or loss of consciousness.  The main takeaway with symptom reporting is that education for athletes, parents, and coaches is an absolute must at the start of every season.  Even more important is re-education throughout the year, which can be as simple as impromptu quizzes at the end of a training session.

Neurocognitive Evaluation: Neurocognitive exams can be administered with a paper-and-pencil or computerized testing module.  These test batteries evaluate various neurocognitive performance indices such as verbal memory, visual memory, reaction time, and visual motor processing speed, and impulse control.  While neurocognitive testing has demonstrated superior sensitivity and specificity for determination of a sustained SRC, there a few limitations that must be considered.  First, there are issues with athletes “sandbagging” the baseline exam, especially those at the collegiate and professional levels.  These athletes are aware of the ramifications of their baseline score, a poor score at the start makes it that much easier to surpass if a SRC were to occur mid-season.  This limitation is more directed toward the paper-and-pencil exams, as the computerized modules are typically equipped with validity benchmarks.  When an athlete is subjected to neurocognitive testing post-SRC, they are often administered multiple (3-5) exams within a very short time period, potentially inducing practice effects.  Essentially what this means is that athletes may score higher on these exams just because they are more familiar with the test itself and may learn testing strategies to score higher.  When these exams are administered to non-concussed control athletes over the same time period, baseline scores are typically surpassed.  Therefore the question becomes, should concussed athletes be required to best their baseline scores in order to be cleared to play?

The last thing I want to discuss is the administration of these neurocognitive exams.  Athletes are seated in a quiet room alone to minimize any distractions – almost the exact opposite of their dynamic sporting environment.  This situation begs the question of the generalizability of the results given the conditions.  During training and competition, athletes are required to interpret task relevant (e.g., opposition and teammate position) and irrelevant (e.g., crowd noise) environmental cues while performing complex motor tasks.  Further, these tests do not account for mental or physical fatigue.  An athlete may perform to “baseline” during a computerized exam, but do they demonstrate this same performance in the 4th quarter?

Balance / Sway Measures: The two most common balance and sway measures post-SRC are the Balance Error Scoring System (BESS) and Sensory Organization Test (SOT).

                                      BESS                                               SOT

The BESS test is subjectively scored by the clinician as the athlete completes various stances on two surface conditions (flat and foam) with their eyes closed.  Error scores are calculated (e.g., opening eyes, lifting hand off hip) for each stance condition over the course of 20 second trials. Despite athletes typically requiring a greater recovery time, BESS data has demonstrated impaired postural control up to 3-5 days post-SRC.  However, recent review papers on the BESS has demonstrated inadequate reliability in a clinical setting (< 0.75), and this may be attributed to the subjective nature of the test (e.g., different clinicians analyzing the same athlete over an acute time frame) and the aforementioned practice effects from repeated testing.

On the other hand, the SOT produces objective balance scores utilizing dynamic posturography under six different stance conditions.  Sensory deprivations under certain conditions allow the SOT to determine visual, vestibular and / or proprioceptive impairments.  Not surprisingly, the SOT has demonstrated superior sensitivity and reliability, when compared to the BESS.  Reviews of SOT data have demonstrated balance impairments up to 10 days following a SRC.  However, researchers question the practicality of the SOT, again due to its analysis of static posture not representative of dynamic sporting movements.  Additionally, the SOT is a very expensive tool, excluding many concussed athletes from access to this type of analysis.

So you have stated the issues…what are the solutions?

To reiterate, I believe the above-mentioned assessment tools have great clinical utility and should absolutely be implemented prior to- and post-SRC.  My concern lies in the ability of these tools to translate into a dynamic sporting environment that poses a potentially  heightened risk for a lower body injury post-SRC.  However, recent gait analysis in concussed athletes has demonstrated locomotor deficits that extend beyond the resolution traditional SRC management tools.  Post-SRC, adolescent and collegiate athletes have demonstrated slower walking speeds, greater frontal plane instability, and decreased cognitive performance as the gait task becomes increasingly difficult (e.g., performing a dual motor and/or cognitive task).  Studies have also obstacle avoidance strategies during gait that suggest deficiencies in executive functioning, spatial awareness, and information processing.  It is recommended that gait analysis be included within a SRC assessment protocol, but more research is warranted to determine best practices in sport.  Perhaps it is best to have the athlete perform various walking tasks (i.e., forward, backward, and tandem) while implementing a cognitive task (i.e., reciting the months backwards or counting by threes).

oldham_2017

(Oldham, 2017)

This now brings me to my current research.  Specifically, I am examining jump-landing biomechanics in adolescent and collegiate athletes with and without a history of SRC.  My (current) first study is in the adolescent population.  Thus far, our data has shown landing mechanics that would suggest a greater risk of injury to the lower body in those who have sustained a previous SRC.  Post-SRC, athletes are demonstrating greater ground reaction forces and loading rates, increased knee valgus angles, and less sagittal knee ROM during various landing tasks.  A large sample size is necessary before making any definitive conclusions, but if these patterns hold with a larger n, it may start to provide a biomechanical explanation as to why athletes are at greater risk for a lower body injury post-SRC.  It has been suggested that subtle cognitive and neuromuscular impairments linger well after an athlete has been cleared for sporting participation.  Biomechanical analysis of dynamic, complex movement tasks may help reveal these abnormalities that are not detected by our traditional reporting measures.  The goal moving forward with these studies is to incorporate cognitive stressors during the jump-landing maneuvers to make the analysis more sport-specific.  With the tools and the assistance of my current research, it is the hope that we will be able to further advance and develop appropriate lower body movement screenings that will be quintessential to any SRC toolbox. Stay tuned!

(Adolescent landing biomechanics from my first concussion study)

Thanks for reading!

Jason

Twitter: @JasonAvedesian

Email: jason.avedesian@unlv.edu

 

#BernsteinBuzz – September 2018

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Topic: How to mitigate cognitive noise?

 

The #BernsteinBuzz, an interdisciplinary effort to studying skill acquisition, is a monthly conference call series started by Harjiv in May 2018. With participants spanning all backgrounds, we bring together those in coaching, research, biomechanics, neuroscience, rehabilitation, and psychology, just to name a few. In memory of Nikolai Bernstein, a Russian neurophysiologist and pioneer in motor control and learning, our aim is to use each other’s strengths to build each other’s weaknesses and provide our industry with a new perspective of philosophy and science. These calls are open to anyone, please reach out to Harjiv at singh.harjiv@gmail.com.

Using this platform, we will share each call’s recordings. Thanks!

#BernsteinBuzz – August 2018

220px-Cyclogram_Gastev_TSIT

 

The #BernsteinBuzz, an interdisciplinary effort to studying skill acquisition, is a monthly conference call series started by Harjiv in May 2018. With participants spanning all backgrounds, we bring together those in coaching, research, biomechanics, neuroscience, rehabilitation, and psychology, just to name a few. In memory of Nikolai Bernstein, a Russian neurophysiologist and pioneer in motor control and learning, our aim is to use each other’s strengths to build each other’s weaknesses and provide our industry with a new perspective of philosophy and science. These calls are open to anyone, please reach out to Harjiv at singh.harjiv@gmail.com.

Using this platform, we will share each call’s recordings. Thanks!

“Syntax of Action” – Part 1 – Enhanced Expectancies.

Motivation, movement, and motor share the same Latin root (movere, to move). In sport, motivation is used as a description of drive toward some goal usually in terms of level of intensity and direction of movement and also as a study of its causes and consequences.

Ryan and Deci (2000) described intrinsic motivation as, “inherent tendency to seek out novelty and challenges, to extend and exercise one’s capacities, to explore, and to learn.” As coaches and practitioners, we have fallen accustomed to this idea of blocked and random practice because it facilitates what is learned. Meanwhile, we tend to forget that there is a success and challenge bandwidth for instructing and constructing learning and performance pertaining to how a skill learned. After all, expectancies for personal performance appear to serve a task readying function, creating a proactive rather than a reactive motor system. Movement-system readying occurs through pre movement excitation or inhibitions mechanisms which are associated to both attention and cognition. Expectancies anticipate rewarding properties of significance fulfilling a performer’s needs. They influence working memory and long term memory biasing our motor system to expected stimuli. Self efficacy or confidence, is more than just a consciously experienced perception. It is a function of control, significance, and achievement, influencing situation specific sense that he or she will be able to effect the actions that bring about task outcomes (Bandura 1977). Throughout the next couple of blog posts, I’ll be digging into the motivational and attentional affects on motor learning and performance. My goal is to shed light onto the importance of instructional cueing and feedback with the purpose of achieving movement automaticity. It’s interesting to think about performer’s who are ‘in the zone’, have the ‘hot hand’, are considered ‘clutch’, and are able to perform even as conditions continue to vary.

(Social Comparative Feedback)

A common approach in sport today is to provide individuals and teams with veridical feedback about their own performance in reference to a standard or gold standard. Competence, or having a sense of growth and the possibility of future success, is hindered if feedback is considered bad or not enough. Normative feedback is a tool used to support competence and relatedness, or showing that others are in similar situations typically given as information such as the average performance scores of other performer’s. While the research remains limited within the social comparative feedback realm, this idea of enhanced expectancies is embedded in the dopamine response literature which I will review towards the end of this series. The studies that have included such interventions have seen increased frequency and low amplitude (improved efficiency in motor control) in balance when performer’s were given normative feedback suggesting that their performance was better than average even when it wasn’t (Lewthwaite and Wulf, 2010). Learning and performance was improved through retention. Now of course, in practicality, we don’t want to lie to our athlete or patient, but we want them feel successful. I’ll touch on positive feedback in the next post, because I know thats what you’re thinking. Another study showed that normative feedback has a functional motivation affect that directly influences physiological changes at the level of stability control specifically in the soleus and peroneus, both muscles that function primarily for plantar flexion (Navaee et al., 2016). Similarly, Hutchinson et al., (2008) showed greater tolerance for sustained effort in a continuous force production task with lower perceived exertion as a function of positive normative feedback. The role of positive normative feedback is to reduce nervousness about ability during performance. In contrast, negative feedback, a sense of outside control, induce self regulatory mechanisms which in turn allow performer’s to focus more on bodily movements (internal focus) and other processes that hamper learning and performance.

This makes sense. When we are told our performance is on average similar to others within the same performance domain, we feel good as compared to it being the opposite. Moreover, it is conceivable that a success with challenge approach is a function of the resultant dopamine response which may give way to a variety of beneficial learning and memory effects often attributed to challenge or task difficulty. Think about it. Dopamine will dampen when we are challenged to do something. For example, if we have just taken the lead as a team in a basketball game but the other team comes back and takes the lead again leaving us with the last possession, this level of dopamine will only amplify to the impact of subsequent positive cues, strengthening the learning effect. This may be a terrible example, so let’s try another one. Challenge is a risk to expected reward. Let’s take a volleyball outside hitter for example. After five kills in a row, she is blocked twice, and therefore her movement, awareness, and swing power will constrain because now its about not making a mistake. Only when her coach says, “keep swinging away” will her level of dopamine increase because in her task readying space, she feels ownership and less nervousness as compared to a coach saying, “tip the ball down the line.” One of the main takeaways is that it is more likely a player will make a mistake after a mistake is made. We will continue this chat in further posts. Giving social comparative feedback to make performer’s feel as if their results are on par with those amongst them is crucial, especially for novice performer’s. At the same time, it allows performer’s not to think too much about their mistake. I hear it all the time.

“You can’t miss this serve”

“You’ve only made 3/8 from the three point line, so pass the ball”

Stuff like this.

Back to my first point. Coaches and practitioners are more keen on changing what is learned as compared to how it is learned. Conditions of practice are impactful and it really matters. What also matters is the unique interplay between how conditions of practice facilitate positive adaptation.

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While many intuitively may provide such feedback, others may be more focused on correcting errors, with unintended consequences for motivation and learning. In the hippocampus, learning increases the survival of newly generalized cells into differentiated neurons to the extent that the learning experience is new, effortful, and importantly successful (Shors, 2014). Feedback is learning, but we’re stuck looking at performance.The problem is that that we like to stop after some arbitrary criterion is reached. Concepts like overtraining and over practice start to create assumptions in our mind that take away from the importance of continuing practice. Performer’s who do not have a great deal practice beyond the stage of initial performance probably do not experience the beneficial increase is resistance to stress, fatigue, and interference that comes from extended overlearning. We are idiotically consumed by creating these habit patterns and we disallow the motor system to perform under stressful conditions where feedback and instruction are the main driver towards optimal performance.

Concepts like overtraining and over practice start to create assumptions in our mind that take away from the importance of continuing practice.

The point here is that performer’s need to develop many different cognitive sets which can be switched from one to another readily, and can include the same stimulus as members of different cognitive sets.

We are idiotically consumed by creating these habit patterns and we disallow the motor system to perform under stressful conditions where feedback and instruction are the main driver towards optimal performance.

The key takeaway from this is that there needs to be variability within the success and challenge bandwidth which is a function of practice conditions (i.e blocked and random). We talk a lot of the freeing of degrees of freedom, but tend to forget that this ‘freeing’ is a result of us as performer’s feeling good about our performance. Giving normative feedback and asking performer’s what they think about their performance is a key ingredient to the perceptual motor landscape. Social comparative feedback is one of the “syntax of action” that influence motivation and attention in motor learning, control and performance. Future research needs to study the influence of social comparative feedback within competitive team sporting events. I hope this makes you think a little bit!

Conditions of practice are impactful and it really matters. What also matters is the unique interplay between how conditions of practice facilitate positive adaptation.

 

Love and Light,

Harjiv Singh

References

Bandura, A. (1977). Self-efficacy: Toward a unifying theory of behavioral change. Psychological Review, 84, 191–215

Hutchinson, J. C., Sherman, T., Martinovic, N.,&Tenenbaum, G. (2008).The effect of manipulated self-efficacy on perceived and sustained effort. Journal of Applied Sport Psychology, 20, 457–472

Lewthwaite, R.,&Wulf,G. (2010b). Social-comparative feedback affects motor skill learning. Quarterly Journal of Experimental Psychology, 63, 738–749.

Navaee, S. A., Farsi, A., & Abdoli, B. (2016). The effect of normative feedback on stability and efficacy of some selected muscles in a balancing task. International Journal of Applied Exercise Physiology, 5(1), 43-52.

Ryan, R. M., & Deci, E. L. (2000). Self-Determination Theory and the facilitation of intrinsic motivation, social development, and wellbeing. American Psychologist, 55, 68–78.

Shors, T. J. (2014). The adult brain makes new neurons, and effortful learning keeps them alive. Current Directions in Psychological Science, 23, 311–318.

Smooth Sailing the Rough Waves of a Research Project

The entire research process is a demanding, yet rewarding endeavor which can kindle a positive revolution within our scientific community when completed successfully.  Thus, I would like to share with you how I go about initiating, processing, and completing a research project.  To provide context, I successfully defended my Master’s thesis earlier than what is typically anticipated, and I am currently going about the same process for my PhD dissertation studies.  While I do not claim to have all the answers, these tips may be especially helpful to first-year graduate researchers entering a program that requires completion of a thesis / dissertation project.  I also hope to provide new information for anyone looking to initiate a new research project.  In this post, I’ll go step-by-step through my methods for successfully completing research.

Step 1: Come prepared to bring the heat

A very basic requisite to starting a Master’s or PhD program is that you should have some semblance of an idea for a research project that you wish to accomplish during your time.  This should be based off your program’s current area(s) of study, which you have chosen based on your personal research interests.  It helps to come prepared with research ideas so that you initiate early discussions on these potential topics with your advisor.  I came to my Master’s advisor, Clark Dickin, with 3 potential thesis ideas.  After more detailed discussions early on in my studies, I finalized my thesis topic;  Examining the influence of warm-up strategies on landing mechanics in female volleyball athletes.  Those preliminary conversations helped my advisor gauge my personal research interests.  This is something you want known from the onset to allow for more centered conversations, which will help guide your journey deeper into the research process.  I had a very similar conversation with my PhD advisor, Janet Dufek, and we are now fully pursuing my dissertation studies;  The influence of prior concussion injury on biomechanical landing strategies in adolescent and collegiate athletes.

Step 2: Get involved ASAP

At the start of my Master’s, I had very minimal research experience.  My interest was spurred early by getting involved with the studies being completed by my advisor and second-year graduate students.  I was able to learn how to create informed consent sheets, the ins-and-outs of IRB (a fun process at times…), the proper placement of landmarks on a participant, collecting and analyzing data, etc.  Regardless of the field of study, more than likely you’ll be starting a graduate program without a ton of prior knowledge on the entire research process, so getting “in the trenches” from the onset is extremely beneficial, especially in fields that require multiple pieces of equipment for data analysis.  Even if you have previous experience, every lab and research group is different and there will always be an adjustment period. This step requires you to be PROACTIVE.  Take the necessary initiatives to learn the intricacies of your field and your lab/labmates, it will pay off in the long run once you’re tasked with completing your own research project.

Step 3: READ, READ, READ…systematically

Sound advice you will hear from most members of the scientific community in terms of research is to read, read, read.  However, you have to be very smart in how you initiate your review of the current literature.  A tip I was given early on from Joe Eisenmann, a previous mentor at Michigan State, is to start your overview of the research with comprehensive / systematic reviews and meta-analyses.  Bonus points for reading literature that is from the last 5 years (+/-) in order to engage yourself in the most updated advances within your topic of interest.  Typically, the most up-to-date systematic reviews/meta-analyses will provide great insight into a particular topic and have a reference list that runs into the hundreds.  Collecting a large database of research from different authors also provides many different perspectives on the same (or relatively similar) research (more on this, in step 4).  Your own personal investigations (through reading!) of these references will lead you well on your way to a thorough understanding of the research endeavor as it relates to what’s been completed previously, with your research providing new insight!  In terms of reading research, I strive to read at least one related research article per day in an attempt to grow an expansive knowledge base of the specific topic, along with an understanding of related sub-topics.

Step 4: Create a master summary table

If you’ve followed me on Twitter long enough, you know I’m a very big advocate of creating a literature summary table.  Below is an example from my current dissertation research.

lit_summary_table_pic

After reading an article, noting the major aspects pertaining to the study has significantly improved my understanding of a particular author’s viewpoint and how it relates to the literature as a whole.  In this sense, you are attacking an article from three distinct mediums: reading, writing, and summarizing in your own literature review for your thesis / dissertation (final step).  In completing this summary table for an entire topic (i.e., lower extremity injury risk post-concussion), you will allow yourself the opportunity to explore what has been previously studied, but more importantly, a stepping stone to the next crucial steps needed to further the research.  I’ve also found this method helps me get into the all-important “writing zone” for my own research- it is exciting to explore an area that has little to no research breath!!  While on the surface a summary table may seem time consuming and daunting, when completed correctly it’s actually quite the opposite- especially when writing sub-sections of your literature review.  Let me explain…

Step 5: The sectional summary tables

Whether it be a thesis or dissertation, your literature review will likely be broken into sections.  In parallel, you’ll want to create sectional summary tables branching off your master summary table.  This will help tremendously in keeping all related material in convenient locations.  For example, you will notice in the summary figure above, I referenced Lau with a highlighted 1C, a designated category for my overall literature review.  Further, I broke up the sections using summary table categorizations (see reference guide below).  Utilizing the tables, along with CLT+F to find “key” words or phrases, will allow you to be more efficient in the writing process.

thesis_lit_review_categorization

Step 6: Cue the horror music…writing your research paper

…BUT it doesn’t have to be if you have followed the previous five steps!  The hardest part to writing a research paper is those first few typed lines, but writing out the summary tables should give you a great starting point.  I have also found it extremely helpful to build (and defend!) time into each day that allows for writing the research paper.  It can be 30 minutes or three hours, but writing each day helps generate and sustain the momentum necessary to produce effective work.  One line leads to one paragraph, one paragraph leads to one page, and so on.  By building on your previous work each day, you’ll not only make great progress, but you’ll feel a tremendous sense of accomplishment.  Additionally, while most of our modern lives are electronic, it doesn’t hurt to save each daily document edits in a new file (noted with the date) in case said electronics do fail us.  I’d also highly recommend sending portions of your writing to your advisor at a time, that way you can continue to write while your previous writing is being reviewed and continue to build on each step of this process.

One theme I’d like to you to take away from this post is the value of consistency.  Whether it be staying up-to-date on the latest literature or writing your own document, consistency trumps all when it comes to research.  Keep in mind that from start to finish, you are looking at a project that takes roughly 18 months to complete (at minimum).  Those who are consistent in their endeavors usually produce the highest quality, and most applicable research.  Whether you are a first-year graduate student or an experienced researcher-practitioner, I hope my experiences in the research process offers some information that may be helpful for your initiatives.  As always, feel free to reach out!  I’d love to hear from you in regards to methods that have been most beneficial to your research.

– Jason

Twitter: @JasonAvedesian

Email: Jason.Avedesian@unlv.edu

Neuroplasticity and the Myth of Muscle Memory: An Introduction.

 

We marvel at the creativity of action. Yet, this abstract representation of the limitlessness of the human body is often boiled down to “muscle memory,” a made up summation of the craft that beautifies the power of the brain and its relevancy. Needless to say, it is not that simple. The behaviorists studied what was observable, while the structuralists studied action through the lens of intention and consciousness. Both were very successful in aiding the revolution of theory. However, neuroplasticity, or the the idea of variability and noise as an informative biological feature of movement remained obsolete. While the popular definition of neuroplasticity still exists around experience and the structural brain changes resulting from the formation of new connections by dendritic spine growth and enhanced internal representations, how does an elite level athlete activate cognitive control processes (adaptation) during complex and constrained motor performance? In other words, is creativity simply a result of muscle memory coming from this plasticity of experience?

Traditionally, the idea of movement variability was outcome dependent. As a result, any deviation from an intended movement pattern was constituted as error. It wasn’t until much later that researchers found such deviations to be potential sources of information in the process of analyzing and monitoring biomechanical qualities. While “muscle memory” confuses adaptation, learning, and performance as simple global parameters which define output, we tend to forget that variability is present in kinetic and kinematic parameters which control basic output. Thereby, creating a system which represents low outcome variability as a resultant of high movement coordination variability. This ability of our system to achieve a task goal through different patterns of coordination defines the compensatory and flexible nature of our ability to actively engage in our perceptual-motor landscape. In fact, it is within this variability that neuroplasticity is honed.

The realm of sport performance and rehabilitation has been very structured in the past. From sets and reps to a linear progression of more complex movement, and to the use of garbage cans, cones, ladders, and whatever else that has no relevancy to skill acquisition. Instead, props like these calibrate and attune the performer to the wrong interventions, many of which won’t transfer. For example, a hurdle jump will not make a volleyball blocker jump higher when there is no ball, transition, visual cue, etc. Creative movement is not just the interaction between different body parts, but an interaction with the environment through perturbation, adaptation, responsiveness, attention, intention, etc. In fact, as Orth et al., (2017) says, its adaptive variability. As animals, we have been resourceful since the onset of our evolution, constantly trying to solve motor problems rather than repeat solutions. We don’t look for creative solutions, we discover them according to the various task relevant and irrelevant changing demands of the organism-environment interaction.

Yes, memory plays a role in the performer’s ability to interpret this interaction. Memory is generally split between long term, short term, and working memory.

Long term memory – A vast resource that represents, or models, regularities in the co-occurrence of elements of information (Barnard and Redgrave, 2006).

Short term memory- The capacity to keep a small amount of information in mind in an active, readily available state for a short period of time (Saussereau et al., 2014).

Working memory – Processing resource of limited capacity, involved in the preservation of information while simultaneously processing the same or other information (Baddeley, 2012)

A muscle clearly can’t store memory. Muscle fibers do not have a separate independent mind of their own. Of course, when accepted as truth by a large number of people without proper investigation, a myth can create cultural change. The idea behind muscle memory is that muscles can function to produce a more receptive motor cortex through its ability to adapt to different training loads and cognitive demands. This happens through our brain’s capacity to store information, strategize, and create effective solutions. It is an interplay of emotion, expectations, autonomy, instruction, motivation, and attention. None of this is originates in the muscle itself, therefore, the muscle itself is never automatized.

So the question proposed in the beginning was how does an elite level athlete activate cognitive control processes (adaptation) during complex and constrained motor performance? In other words, is creativity simply a result of muscle memory coming from this plasticity of experience? My hope is you can formulate that answer yourself with the information above. The motor learning literature is filled with work on practice conditions, stages of learning, contextual interference, motor control, measuring performance, action preparation, feedback, retention, and transfer, all of which play a significant role in adaptive variability. However, one thing I do want to briefly mention is the role of language in all this. Applicable to coaches, is the way we instruct and facilitate learning and practice. Numerous studies have been conducted on the role of attentional focus, autonomy support, and enhanced expectancies which are inherent attributes to cueing. Whether its providing choice (task relevant or irrelevant), directing performers to engage in an external focus, or providing social-comparative feedback, sport performance is not just the training load. It is the cognitive constraint that your language has on a performer’s resultant movement strategy. Our assigned sets and reps meaning absolutely nothing if variability isn’t induced in the how and what, not just the when. Muscle memory is the adaptive variability that fluctuates the perceptual motor landscape. And neuroplasticity is  the longterm retention of this adaptive variability. To sum up, this is just an introduction to many other topics that are relatable, and I think its important to realize that as coaches and practitioners, we aren’t inducing muscle memory. We are reorganizing our ability to consolidate memory from differential practice in order to satisfy a coalition of organismic, task, and environmental constraints.

With Love and Light,

Harjiv Singh

 

References:

Cowan, N. (2008). What are the differences between long-term, short-term, and working memory?. Progress in brain research, 169, 323-338.

Olesen, P. J., Westerberg, H., & Klingberg, T. (2004). Increased prefrontal and parietal activity after training of working memory. Nature neuroscience, 7(1), 75.

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