Theories and paradigms of foot function. Beneficial or a symptom of our inability to tolerate uncertainty?


From the moment we start university, biomechanics is instilled in us as one of the pinnacles of practice. Understanding how the human body moves and works is seen as ‘the key’ to helping solve all musculoskeletal ailments of the lower limb.

Debate often focuses around which of the different theories or paradigms of foot and lower limb posture and function are the most validated or ‘best’. However, the thing I have always had difficult reconciling is if any of our theories of foot and lower limb posture and function are correct, why has this has never translated into consistent, high-quality study findings? Why is it that our biomechanical treatments help some but not all, despite high levels of anecdotal success.Were things ever this simple?

The more I search and I read, the more I’m convinced that this isn’t a problem of a specific biomechanical theory, but a problem with how we utilise and apply these in our practice. You see, when I searched, I found very little evidence to suggest we comprehensively know how the foot works. So how can these biomechanical models explain how the foot works, without the evidence base to do so? And that is the crux of the issue – they can’t. So if nobody can explain how the foot works, why do we continue propagate theories of foot function as fact?

A theory or paradigm of foot function is a hypothesis of how the foot works. Since we don’t have concrete evidence to show how the foot works, we have to make assumptions in order to provide a comprehensive theory. The purpose of a hypothesis or theory is to guide research and design studies. Using findings from those studies we reconfirm and build on that theory to build evidence of foot function on a strong foundation of information

While hypothesis’ are beneficial to research, utilising them in practice requires careful consideration and an open and honest dialogue with the patient. However, based solely on anecdotal and correlative evidence, we are quick to adopt them into practice and communicate them as fact. The problem with this process is the powerful amount of cognitive biases that can enter our thought process when evaluating our patients results and how this stifles the iterate process of evidence based medicine. When new evidence arises to suggest that some fundamental assumptions aren’t true, we have to overcome these significant cognitive  biases, as well as potential financial and personal investments in the theory, in order to implement truly evidence based medicine.

Why does this happen?

Evidence based biomechanical practice is an absolute minefield of data that is often contradictory and not comprehensive, leaving us in a state of uncertainty and confusion. Sports Podiatrist Ian Griffiths in a blog post about biomechanical paradigms not only identifies this, but questions whether we need them at all. He highlights that in this confusing mess of data, a theory can be a comfortable compromise providing a set of rules, establishing right or wrong and provide a simple, repeatable process, whether this is established as factual or not.

He argues that instead of learning a theory or paradigm of foot function, we should instead learn a series of topics which if a Podiatrist was proficient in, he believes would provide all the information and evidence required to comprehensively assess and treat a patient. These were;

Research Methods & Critical Appraisal

History taking & Communication



Basic Engineering

Materials Science

Pain Science

While I agree with his suggestion, I think we need to consider what may be the underlying cause of why we continue to seek out foot function theories and paradigms.

Tolerating uncertainty – the next medical revolution?

In an article with the same title, Simpkin and Schwartzstein state:

“Our quest for certainty is central to human psychology, however, and it both guides and misguides us. Although physicians are rationally aware when uncertainty exists, the culture of medicine evinces a deep-rooted unwillingness to acknowledge and embrace it. Embodied in our teaching, our case-based learning curricula, and our research is the notion that we must unify a constellation of signs, symptoms, and test results into a solution. We demand a differential diagnosis after being presented with few facts and exhort our trainees to “put your money down” on a solution to the problem at hand despite the powerful effect of cognitive biases under these conditions.

Too often, we focus on transforming a patient’s gray-scale narrative into a black-and-white diagnosis that can be neatly categorized and labeled. The unintended consequence — an obsession with finding the right answer, at the risk of oversimplifying the richly iterative and evolutionary nature of clinical reasoning — is the very antithesis of humanistic, individualized patient-centered care. We believe that a shift toward the acknowledgment and acceptance of uncertainty is essential— for us as physicians, for our patients, and for our health care system as a whole.”


I think the authors identify what is behind why we hold theories with certainty and present assumptions as fact. That many of us aren’t taught how to tolerate the uncertainty of evidence based medicine and instead learn to practice in a way that prioritises absolute certainty, despite the fact that the scientific process underpinning the creation of medical evidence can never lead to such statements. This can lead to clinicians moving away from the use of medical evidence, as it cannot provide the certainty that they expect. Instead well-meaning clinicians may choose to find certainty in a theory or paradigm due to the appeal of providing all the answers.

This process of seeking certainty can blind us to the cognitive biases and fallacies we have to accept in order to believe the assumption these models come with. I think we also underestimate how difficult these cognitive biases make it to identify what is an assumption and what is an evidence based statement, especially when there are a number of other hidden assumptions. For example:

Root Theory suggested there was a physiological ‘normal’ foot position and theorised that ‘abnormal’ posture or movement outside this norm was the cause of injury and pain. We now know this isn’t the case, however this hasn’t stopped people continuing to hold other underlying assumptions from this theory. Such as the concept of needing to ‘correct’ foot posture, that devices such as foot orthoses can ‘correct’ foot posture and that foot posture or abnormal movements plays a causative role in all injuries of the foot and lower limb. None of which have any grounding in evidence.


Understanding how a lack of tolerance for uncertainty affects our foot function theories and paradigms, also identifies the problems our profession faces when implementing evidence based practice more widely. For example, how these types of cognitive biases can influence how we deal with subject specific responses. We’re almost never presented with a patient that represents the exact population from a study, meaning that there will always be some variability in how we implement evidence into practice. There is also a wide variety of subject specific responses to conditions, assessments and management plans, which aren’t often captured in the statistical analysis. Therefore implementing evidence requires not only a good understanding of the wider evidence base and current principles informing practice but the cognitive flexibility in order to apply this to patients that aren’t the typical population or don’t have a typical presentation.

The way I try to explain this problem to some of the students that visit my clinic is that clinical practice is like trying to solve a never ending jigsaw puzzle without the original image. As we put together the pieces, making assumptions about what we’re looking at is useful in helping us put together pieces. “Is that a house, or maybe it’s a barn?” There comes a point in time when we see that the picture or part of the picture is different to what we thought and those assumptions are no longer helpful in solving the puzzle. Sometimes it is also better to step back from trying to figure out the overall picture and look at pieces individually, unencumbered by previous assumptions or the weight of trying to solve the entire puzzle. What you never do in a puzzle is cut the pieces to fit your idea of what it should look like. How that happens is holding onto an assumption so tightly, you can’t see the picture any other way.

So what do we do from here?

Knowing all of the above, it is difficult for me to suggest that we should keep teaching and utilising theories and paradigms of foot function in clinical practice. Establishing how our inability to tolerate uncertainty affects foot function theories and paradigms, also alludes to how this issue can affect our ability to implement evidence based practice more widely.

As individuals I think we need to improve how we tolerate uncertainty in practice. However, I don’t think there is one single process to learn this. I think it is an individual journey.

Personally, I try to accomplish this by reading widely and surrounding myself with information and evidence that challenges my viewpoint. I try to find mentors with skills and experience I don’t have, that can provide significantly different opinions. I write down and try to argue against my own treatment/management plans to identify bias that may have entered into my thought process in the moment.

I also communicate my uncertainty to my patients. I highlight what we do and don’t know and why I decided on my suggestions. This was a massive leap of faith, but I was surprised how well patients appreciate genuine honesty and be treated like a partner in their own management.

As a profession, I think we need to come together and identify what parts of our practice are evidence based, what parts are inferences based upon high quality evidence and what are assumptions with limited to no support. I think we also need to identify what parts of foot function theories and paradigms are helpful and worth exploring further and what is no longer supported by the evidence. Which are the obvious suggestions. What this looks like and how it is accomplished, I have no idea.


Thank you for reading.

I spent a lot of time considering what should be my first piece of writing. This website was first conceived in April 2018 and it has taken me a year of thinking and writing before settling on this as my first topic.

This topic is of interest to me because I think our inability to tolerate the uncertainty that current practice requires is a barrier that limits our ability to truly implement evidence based practice across a multitude of topics. So before I start talking about new evidence and challenge people’s beliefs, I wanted to put a stake in the ground first and outline this issue.

The risk of writing about this or any other topic is that I’m going to come across like I’m superior. But nothing is further from the truth. The reason why I feel I can talk about this with some authority is that I went through this from start to finish. A good chunk of this last year writing has been me wrestling with my own beliefs and biases. Getting to a point of clarity where I think I can communicate these ideas and concepts in a way that is fitting with the current evidence.

What I really hope will come from this is people can benefit from my time spent working on this rather than having to start from scratch. More importantly, I hope I can draw attention to topics and have people talk and challenge what I write. Because as I said above, one of the ways I go about improving myself and my practice, is surrounding myself with new and challenging viewpoints

Alex Murray Podiatrist

Alex Murray is a Podiatrist working in private practice and the founder of website Making Sense in Podiatry. He's passionate about helping other clinicians make sense of evidence and clinical practice with a core philosophy of exploring the complexity of human beings, embracing the uncertainty of clinical practice, and avoiding overly reductionist thinking. In addition to his undergraduate degree from La Trobe, he also holds a Post Graduate Diploma in Sports and Exercise Medicine from the University of Otago. He has experience with both national and international athletes and has recently transitioned to focusing primarily on helping the general population and local athletes manage their pain and achieve their goals.

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