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Tuesday, June 6, 2023

Search for Congruence

Brent Brookbush

Brent Brookbush


The Search for Congruence

A model for the refinement and multiplication of ideas in human movement science

by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS

Congruence (symbol: ) is the state achieved by coming together, the state of agreement. The Latin congruō meaning “I meet together, I agree”. As an abstract term, congruence means similarity between objects. Congruence, as opposed to approximation, is a relation which implies a species of equivalence. - http://en.wikipedia.org/wiki/Congruence

As an educator it becomes important to consider how you think about the information you teach, and how you can impart that “thinking” ability or relay that process to students. This is known as meta-cognition:

Metacognition is defined as "cognition about cognition", or "knowing about knowing." It can take many forms; it includes knowledge about when and how to use particular strategies for learning or for problem solving. There are generally two components of metacognition: knowledge about cognition, and regulation of cognition. - http://en.wikipedia.org/wiki/Meta-cognition

While constructing the “Predictive Models of Movement Impairment ” that are now featured on my site (also the backbone of my “Corrective Exercise Lab ” workshops and my next book), I struggled with teaching the logic I used to construct them. I noticed I was using certain algorithms, ideas, and concepts, but it was far from a tangible model that a student could take home and apply in their daily practice. It is my belief that as an educator I have a responsibility to not only dictate information, but to teach students how to construct the ideas themselves. In essence, relay my thinking process so that students may enhance their ability to formulate ideas, reflect on the information, and apply the same concepts for further development of the information presented.

The one concept that seemed to be pervasive, being mentioned every time I taught the model, was a need for all of the information I currently had to agree with the models I was creating. Every bit of it – textbooks from revered practitioners, etiology of chronic orthopedic pathology, exercise selection, the NASM model, the Maitland approach, Motor Learning Theory, research studies, meta-analysis, clinical prediction models, logic, case studies, experience, etc… in a word, everything. After all, my goal was not only to create something relevant, but to explain all findings to date and predict the most effective treatment strategies.

It is likely that my underlying desire for things to agree was born, first, from my love of debate and a talent for finding incongruities in logical argument, and second, from my admiration for a certain subset of work being done in theoretical physics. I must give credit to my career as an educator for honing my skills in debunking irrational claims and incongruent arguments in the misinformation machine that is the current state of the fitness industry – after all, I published a book with that objective (Fitness or Fiction: The Truth About Diet & Exercise ). As for the reference to physics; physicists are currently looking for a theory of everything, a model that would find congruence between the standard model and general relativity. This model would serve to explain the nature of all matter and potentially predict the results of any experiment in physics (I know what you’re thinking… “this kid watches way too much Discovery channel”). If physicists are doing it, why not human movement professionals?

If you flip the idea of finding logical fallacies and incongruities into looking for an explanation that would explain why two opposing schools of thought can co-exist, you are left looking for threads of information that coincide, or information that coincides with what you already know about the subject. You try to determine the congruities between the two opposing ideas, or try to validate bits of information from these ideas by looking for congruency with the information you know. If two things achieve the same goal, no matter how opposed on the surface, there are commonalities that are resulting in their success.

An analogy - consider all of the theories, research, assessments, treatment strategies, exercise programs, modalities, outcome measures, prediction models, etc., that you are currently aware of. Now, imagine that each of these bits of information is represented by a single dot on the same pointillistic painting (Example of Pointillism - Seurat, Sunday on La Grande Jatte - See image below) Every dot may be a different color, different shape, and a different size, but every dot is comprised of paint, on canvas, and on this canvas creates a single congruent painting. No matter how different the ideas, if the idea results in successful outcomes it has a place on the same “human movement painting”. Keep in mind, that you are not only aware of seemingly conflicting dots (clashing colors), but there are dots that you are unaware of, and initially this is going to make our painting a little hazy.

Example of Pointillism
Caption: Example of Pointillism

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Example of Pointillism - Goerges Seurat: Sunday on La Grande Jatte - http://www.metmuseum.org/toah/works-of-art/51.112.6

If we start to look beyond just two opposing schools of thought (two dots), and instead start to consider all the information in human movement science (all the dots we know), we start to see a larger picture that could refine our understanding of the human movement system. Potentially, this could lead to a complete understanding of human movement and optimal practice given enough thought, research, practice, analysis and time. Perhaps human movement professionals (PT’s, DC’s ATC’s, LMT’s, CPT’s) like physicists, could work toward “a theory of everything.” A theory that would predict all human movement impairment, the best possible treatment strategy, and the best possible outcomes.

As I continued to teach my “predictive models of movement impairment ” with the idea of congruence firmly implanted in my head I started to notice that I was testing these models against certain subsets of information. It is the idea of finding congruence with these subsets that I term the “Congruence Model"

  1. Theory
  2. Research
  3. Assessment (Observation)
  4. Practice
  5. Outcomes

Although the subsets above are listed in numerical order, they should be thought of as intertwined concepts, each leading-to and affecting the others – (similar to the graphic in the picture below from our live workshop “Advancements in Exercise Selection: Lumbo Pelvic Hip Complex Dysfunction "). Also, finding congruence is not limited to finding congruence between subsets, but within each subset as well. Finally, try not to simply consider this model as a way of refining and therefore reducing the number of optimal practices, but consider how thinking about any idea in reference to the various subsets could multiply ideas.

Teaching the Congruence Model at an "Advancements in Exercise Selection" workshop - https://brentbrookbush.com/online-courses/online-courses/b2cfitness-update/


When I “test (thought experiment, not literal test)” my models for congruence against current theories in the field it is important to make a clear distinction between “scientific theory,” and the word “theory” as it is used in common every-day speech. Often individuals think the term “theory” refers to something that is not proven, but “scientific theory” is not based solely on unproven assertions.

Scientific Theory - “A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of knowledge that has been corroborated by the scientific method, followed by evidence gathered to test their accuracy. As with all forms of scientific knowledge, scientific theories are inductive in nature and do not make apodictic proposition; instead, they aim for predictive and explanatory forces.”http://en.wikipedia.org/wiki/Scientific_theory

I believe a certain level of confusion has developed between how we use the word “theory” in every-day speech, leading to the insinuation that theory is somehow opinion - and worse, because it is “opinion” that individuals have the right to be dismissive of the scientific method and replace well founded theories with their own opinions based on anecdotal evidence. This misstep in logic cannot lead to better practice, and will only slow progress in our field.

In human movement science, theory often refers to concepts that serve to explain the way a system or group of systems interact with one another. Theories may be large over-arching concepts concerning how the human movement system adapts such as Motor Learning Theory, Motor Control, Postural Dysfunction/Movement Impairment, or the General Adaptation Syndrome, they may be theories about fundamental processes that occur within the human movement system such as the cumulative injury cycle, inflammation, Wolff’s and Davies’ Law, sliding filament theory, or may refer to theories from other sciences such as physics, chemistry, biology, and education that are pertinent to our practice.

At the very least, theory serves to give us direction. Rather than test every hypothesis, use every objective measure, and develop techniques for every possible scenario – theory allows us to direct our limited time, effort, and resources toward our most promising ideas. Theory itself is nothing more than a congruent rationale based what we already know, in essences, a foundation from which to build. For example, based on our current understanding of human movement impairment, in Upper Body Dysfunction (UBD) the pectoralis minor has a propensity toward adaptive shortening and over-activity; therefore, developing techniques that would increase activity, strength, or exacerbate adaptive shortening is likely a waste of time and resources. Conversely, the serratus anterior has a propensity to become under-active. Working on the development of better techniques for increasing the activity, rate of recruitment, strength and decreasing the relative length of the serratus anterior is likely to improve outcomes. There is far too much information pouring into the field of human movement science to try everything we are exposed to, not to mention that there may be ethical issues in trying potentially ineffective techniques on a client/patient population.

Back to our analogy, theory serves to fill the space between the dots. The other subsets of information discussed in this article all have the same inherent weakness – conciseness. They contribute one small dot, and often in slow fashion. Theory is the only tool we have that allows us the creative liberty to take a step back and consider what the whole painting is portraying. Just as a new dot may change the picture entirely, theory must remain dynamic and change with new information, but without theory, practice becomes nothing more than an endless series of “if-then” statements. Nothing more than an overwhelming sea of dots with little if any relationship to one another.


The next subset of information is research. Research has received far more attention in recent years due to the push for “evidence-based practice;” – a movement with altruistic intentions to improve the likelihood that individuals will receive the most efficacious care and resources will be used efficiently. Evidence-based practice is getting away from the all-to-commonly used rationale - "it worked for me," (which often means “will not work for everyone, but I’m going to try it anyway”) and moving toward evidence that "this technique resulted in successful outcomes for the majority of individuals within a population." Often programs are not effective for the reasons we think they are, and isolating the variable with research serves to improve the likelihood of successful outcomes while reducing the risks imposed by other variables within the program.

However, in order to use this powerful tool effectively, we must do so with perspective and a cursory understanding of what research is and is not. This movement in medicine, rehabilitation, fitness, and performance enhancement is almost solely based on the results of hypothesis-driven, experimental, quantitative research and holds the randomized control trial, meta-analysis, and systematic review in the highest regard. Although incredibly powerful data, if we are going to limit ourselves to this type of research we have to admit something to ourselves – a single research study is not capable of explaining the intricacies of human movement, in fact, thousands of research studies are likely not sufficient, and we do not have enough research to even begin to create a complete picture. If human movement can be explained by our analogy of the painting, then research is nothing more than an incredibly accurate, but slow-moving paint brush, applying a single dot with each touch to the canvas. Trying to understand the complexity of human movement with scientific research alone is like trying to fight a million-man army with a sniper rifle.

Each piece of research gives us a validation or falsification of a single hypothesis – in essence, a “yes” or “no” to a single direct question (although well-written research can often do more, it is still a very concise bit of information to a single question). One of the mistakes that is often made in the interpretation of research is gross generalization. Individuals will use a single study to validate a group of practices within a multivariate program despite the fact that any one of many variables inherent in those practices could have resulted in the outcome that the research study may or may not support. Research cannot isolate variables and test a multivariate hypothesis at the same time. If research examines a group of practices, then research can only support or refute that all variables combined or one of the variables within the study resulted in the outcome, but that same study cannot isolate the variable from others. If the study does isolate a variable, those findings cannot be generalized to an entire program. Research is like playing “20 questions”, we must consider each research study as a simple “yes” or “no” to one question, that we received within a group of questions, that was likely asked based on a preconceived framework of possible theoretical outcomes. Without a theoretical framework, research leaves far too many gaps to be useful.

So why rely so heavily on research?

Without research there is no scientific theory. I know this sounds like a circular argument (theory needs research and research needs theory), but what it actually highlights is the congruence and integration of these two subsets of information. Within a theoretical framework, research studies may be the single most powerful tool in our search for congruence. Despite the rather narrow scope, the accuracy of research is so high (relative to other contributing information) that unless the research itself is flawed, it cannot be dismissed. Although, not as commonly cited, even negative research that refutes our hypothesis gives us valuable information. Is it not just as important to have evidence that a technique did not work? One type of research I would like to see more of is “comparative practical research” – for example, comparing static and active release protocols or comparing flexibility outcomes using release, release and stretch, and release, mobilize and stretch protocols.

In summary, research is what it is - a yes or a no to a direct question (a hypothesis), a single dot in a mosaic of data points that create a complete picture. If research validates or refutes a hypothesis it is our responsibility to consider an explanation that is congruent with this new information and with our understanding of human movement.

Example of searching for congruence with research from “Refined Static Stretching Protocol

“The question of when professionals should recommend static stretching is not a matter of before or after, but whether or not a muscle exhibits tightness. Studies have shown a reduction in muscular force output post static stretching, and because of these findings, it has been suggested that stretching should be done after exercise3, 12. Neural inhibition, a reduction in musculotendinous rigidity, and changes in muscle length/tension relationships have been suggested when explaining the post-stretching reduction in force production3, 12. However, if a muscle is overactive and connective tissue has adaptively shortened there may be a benefit to pre-activity stretching. In the one study I could locate that selected individuals who exhibited clinical tightness before testing, stretching the tight hamstrings increased performance in a single leg hop test9. Could it be that inhibition and a change in hamstring length reduced resistance to motion and improved length tension relationships?” (for citations and further reading please click on the link – “Refined Static Stretching Protocol ”)


The next subset of information is the basis of our treatment, routine, and program design. I have purposely chosen the word “observation” as this subset embodies all information that is observed by the professional over the entire course of the professional/client relationship. Further, this includes trends seen between patients. Subjective evaluation, objective evaluation, differential diagnosis, re-assessment, functional status, conditioning, the performance of individual exercises, progress, attitude, compliance, communication with the client, the number of modalities, exercises, and techniques that the patient can tolerate per session, etc. all provide us with valuable information. Initial assessment is imperative; however, a professional gathers many times the amount of information over the course of the professional/client relationship than is gathered during the initial evaluation. Consider how a client/patient's attitude toward a particular exercise and the quality with which the exercise is performed changes your strategy for future sessions, and how that successful or unsuccessful outcome affects your use of that exercise with other clients/patients. This information may have a larger impact on your treatment/programming than anything you learned about the patient/client during the initial assessment, and rightfully so.

All of this information you gain through observation has value. Every nuance helps to clarify our painting. We must continually allow our minds to consider why we are observing a particular behavior, and how that behavior is congruent or incongruent with what we thought we understood. How does that change our painting? Just as research influences theory, research, and theory will influence observation. Orthopedic testing clusters are a wonderful example of finding congruence between research and observation. The overhead squat assessment is a wonderful example of theory and observation leading to further research. Although some will proclaim that they need to see research to validate our observations in the name of “evidence-based practice,” let’s get real - most often the research doesn’t exist. We will need to rely on congruence with other subsets of information to validate our understanding of a particular observation until research catches up to decades of dedicated practice and the creativity of many brilliant minds.

An abbreviated example of theory, research, and observation resulting in congruence:

A basketball athlete complaining of heel pain receives a 5/5 on manual muscle testing of the tibialis anterior, has 10 degrees of dorsiflexion (active-assisted range of motion), and palpation of the heel does not replicate the pain. Other than the initial complaint of heel pain this presentation is that of a normal/healthy pain-free individual. However, something is causing the symptom, so further observation is necessary. For this individual you decide to do a kinematic analysis of his jumping (you can buy some very inexpensive and effective applications for your phone camera) - During the loading phase of a vertical jump you note the feet externally rotate, evert, and he adopts an excessive forward lean, further, jumping replicates the pain. At this point, we may have to look to theory and research for more ideas. Although the objective measures found during goniometry and manual muscle testing may not be alarming for less active individuals, the compensation pattern noted during his vertical jump implies relative flexibility and the adoption of a compensation pattern. Could it be that anything less than optimal dorsiflexion (15-20 degrees) is a precursor to pain due to the large external loads placed on his neuromusculoskeletal system? After release, mobilization, and stretch of the appropriate structures, you retest dorsiflexion and have attained 17 degrees, further retesting the tibialis anterior in the new end range results in 3+/5. You recall reading research that indicated that strength is ROM specific, further, that strength throughout range was correlated with better flexibility over time. After performing tibialis anterior activation and integration the individuals scores a 4+/5 on tibialis anterior activation, mechanics and performance improve greatly during his vertical jump, and the individual reports 50% less pain.


Many of you know this is where I love to “geek-out.” This is the subset where we compare, contrast, and look for congruence with the “stuff” we do every day. I am a firm believer in practical education and further believe much could be gained from a more refined approach to the selection of modalities, techniques, and exercises. The question becomes, how do we decide which exercises, techniques, and modalities are better than others? Again, the answer lies in congruence.

A quick example of how our congruence model may lead to refined exercise selection (improved practice):

Observation of film of athletes prior to suffering non-contact ACL strains highlighted an inability to eccentrically decelerate femoral adduction and internal rotation – the muscle most likely to decelerate this motion is the gluteus medius. Could activation, integration, and conditioning of the gluteus medius result in a decrease in the number of non-contact ACL injuries? In theory (movement impairment), it could be viewed that these athletes demonstrate altered recruitment strategies resulting from an inhibited or hypotonic gluteus medius and synergistic dominance the internal rotators of the hip, namely the TFL and gluteus minimus. Could release and stretch of the TFL and gluteus minimus prior to activation of the gluteus medius further improve outcomes? Research comparing various exercises that targeted the gluteus medius while minimizing tensor fasciae lata activity using fine-wire electromyographic assessment showed the clam and resisted side-stepping to be most effective for achieving this goal. –

Selkowitz, DM, Beneck, GJ, and Powers CM. Which Exercises Target the Gluteal Muscles While Minimizing Activation of the Tensor Fascia Lata? Electromyographic Assessment Using Fine-Wire Electrodes. J Orthop Sports Phys Ther. 2013; 43(2):54-64.

Note: The study above is a great example of my favorite type of research – practical and comparative. At some point we need to stop being timid and start testing established methods against one another. Not all techniques, modalities and exercises are created equal. It is time we admitted that some approaches are simply less effective. It is not possible to find a congruent picture of human movement if we treat all ideas as equal. I admit, this is one aspect of this process that is not specifically a search for congruence, but rather a purging of incongruence. A similar process is occurring in research, in which studies are rated for quality and power (see Cochrane Library - http://www.thecochranelibrary.com/online-courses/online-courses/view/0/AboutCochraneSystematicReviews.html ). Rather than waiting for a research study to validate your choices, you can easily compare techniques in practice:

  • Step 1: Test, implement exercise 1, retest
  • Step 2: Test, implement exercise 2, retest
  • Step 3: Compare results
  • Step 4: In a follow-up session compare results using the more effective technique alone to ensure that it was not the combination of both techniques that improved results.


  1. Goniometric assessment reveals decreased internal rotation at 90º of hip flexion, use static release for the TFL, retest internal rotation
  2. Use active release for the TFL, retest internal rotation at 90º of hip flexion
  3. Compare results
  4. In a follow-up session test internal rotation at 90º of hip flexion, only use the “more effective technique,” and retest.

With that being said there is plenty of room for the integration of ideas. I am not suggesting that we compare techniques with completely different intents (for example, mobilization to muscle activation); I believe strongly in an integrated approach. Ideally, many effective techniques will be used in every session. Many of you are aware of the template I use (an expansion of the NASM CES model)

  1. Release
  2. Mobilize
  3. Stretch
  4. Activate
  5. Core Support
  6. Stabilization Integration
  7. Reactive Integration
  8. Subsystem Integration

We can use our “search for congruence” to compare and refine treatment methodologies. Often we have to deconstruct to reconstruct:

The practice of PNF is effective for some individuals with orthopedic impairment and so is Sahrmann’s approach to correcting movement impairment. The techniques they use are vastly different and seemingly in opposition to one another, but what is congruent between these two schools of thought? – They both use specific resisted patterns to alter recruitment strategies, both with the intention of better motor control. If we apply these two schools of thought to a common impairment, “shoulder impingement,” how do these approaches differ and where is their congruence? D1 Upper Extremity Extension (Cobra’s) is a good choice for strengthening external rotators and scapular stabilizers, whereas D1 Flexion generally results in pain and may exacerbate dysfunction. Could it be that some PNF patterns are effective and others could be refined or omitted? Could PNF patterns be added to Sahrmann’s approach? From my point of view, Sahrmann’s serratus anterior activation and D2 extension would seem to be great choices for a home exercise program for this population. (You can see the Brookbush/Fluegel modification of the Sahrmann exercise here - Serratus Anterior Isolated Activation , Serratus Anterior Activation Progression , Serratus Anterior Reactive Integration , ). Integrating methodologies certainly provides more options, and only in comparing various techniques will we find the ideal treatment strategy.

This may seem likely a fairly complicated way of going about exercise selection, but it is what we do. All day, every day for our entire careers. Concerted effort toward a congruent model of human movement, can only lead to a refined and eloquent approach. The integration and comparison of ideas leading to optimal practice.


Outcomes have the final say in our search for congruence. The best possible outcome must be the goal of any treatment strategy, exercise routine, or performance enhancement program. Regardless of how congruent your theory, research, observation and practice, if it does not result in better outcomes there is an incongruity in your approach. The convenient aspect of this subset of information is that we all work toward better outcomes, research is more geared toward outcomes than ever, our observations contribute to our understanding of outcomes, and as I mentioned in the section on practice, we compare the outcomes of various exercises in every session, every day. There are fewer missing dots in this subset than any other. The difficult part is determining where we went wrong when our outcomes are not what we expected.

Incongruent outcomes can be positive or negative. Everyone has experienced the pain of failure, but consider all of the successful methods that we utilize that lack a theoretical mechanism or research-based reason for how they affect the human movement system – How do McKenzie exercises reduce low back pain, what causes cavitations during manipulation and why does it help, what is the mechanism that reduces hypertonicity with release techniques, what role do fascial receptors and fascial techniques play in improving human movement, what is the cellular change that signals protein synthesis and hypertrophy, etc.? I could go on, but I think you get the point. I only mention these practices with missing pieces to reassure those of us in the trenches. As I mentioned at the beginning of this article, there will always be missing dots. Although it is important that we continue researching these issues, we cannot allow missing dots to obstruct progress, or worse still, cause us to dismiss effective practices. If it consistently works, use it - if it doesn’t, don’t. The practices that work but present with missing pieces are the perfect problem to test in this model – do your research, construct hypothesis, theorize, experiment with various practices, and observe other clients and professionals. There is a complete painting, you just can’t see it yet.

Examples of questions with multiple missing pieces that may result in positive outcomes

  • In CVA patients, will the use of release and low-grade mobilizations on mild spasticity prior to neuromuscular re-education improve the quality of movement?
  • Will the use of reactive activation techniques for the gluteus medius prior to sprint training enhance the performance of running athletes?
  • Will the use of regular thoracic mobilization reduce the likelihood of adopting upper body dysfunction (UBD) over time?

There is research that implies that the intention of the techniques or the attributes gained by these techniques may improve outcomes. Further, I have generated these questions from a theoretical model of human movement and my experience implementing that model (observation and practice). I will not deny that I lack sufficient research to confirm the methodology, there are holes in my theoretical model, and in the case of the CVA patient I am not nearly experienced enough to make a prediction based on observations in a clinical setting. How will I know if these are relevant strategies? - What was the outcome? Unless the technique you are proposing is inherently dangerous, or a blatant waste of resources what do you have to lose by setting time aside to test a well formulated idea that is congruent with everything you already know?

If the technique does work, I can continue to hypothesize, read, observe and practice. Eventually, I will fill in more dots. If it works in an unexpected way I have to consider how that affects my understanding of relevant information from the other subsets. If it does not work, I may also need to revisit my hypothesis, but most importantly, I have a responsibility to modify or abandon the activity.

Confession… I allow myself to try a new technique or technique that I am less familiar with every session. I am not talking about something wholly inappropriate, but something outside of my comfort zone. I often try a technique for months (assuming some level of success) before I decide whether it stays or goes. I think it is important to allow myself the freedom to fail for a few minutes every day to ensure that I keep growing. Of course, the outcome then gets fed back into my congruence model and I consider how that compares to the current research, theory, and my understanding of human movement science.


Strange that I would find such purpose in a single word, but In this model, we are searching for the answer, practice, concept, model, postulate or truth that is congruent with all available information. In essence, the term congruence is used to describe a harmonious relationship or agreement between all ideas. Admittedly, my use of this model is rarely formal.. In most cases, the search for congruence is a mental exercise that occurs continually in the backdrop of my mind as I try to synthesize, integrate, compare, and refine my understanding of all human movement science. In consideration of my own quest to find a congruent model of human movement impairment (predictive models of postural dysfunction), it is this model that is continually affording me new ideas, directions, and challenging my own logic. In essence, my predictive models of postural dysfunction are theories, based on research and observations, that predict a set of effective techniques to improve outcomes.

As an educator, I may be more impressed with the power of this model to increase horizontal or lateral reasoning and further entice students to use an integrated approach to solving complex problems in human movement science. It is not dismissive, skeptical for the sake of being skeptical, accepting without consideration, and always leads to better practice and outcomes. It is a disciplined, integrative, and creative approach to better practice.

© 2013 Brent Brookbush

Questions, comments, and criticisms are welcomed and encouraged