Clinical Biomechanics Boot Camps

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Global Podiatry and lower limb related courses and seminars


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“Too many toes” or “all the toes”

I think most of us have heard of the ‘too many toes sign’. This is when there are more than a few of the toes are visible on the lateral side due to an abduction of the forefoot when standing or walking.

This image from a screen grab of video that I did of a case I talk about during the Clinical Biomechanics Boot Camp could just about be considered as the “too many toes” sign:

Below is a screen grab of the video of the other foot. I like to call that one the “all the toes” sign rather than just the “too many toes” sign as all of the toes are visible laterally.

The key point in talking about this case was that it was the right foot that was the painful one and the left one with that severe “overpronation” was not the problem one. This means that the “too many toes” sign is not something to be necessarily worried about. What you need to be worried about is the forces behind the foot posture and be worried about them if they are high.

The “too many toes” sign is not really good terminology and is just something that clinicians may say to patient as part of a conversation. It is not a diagnosis. It is probably better to use the components of the Foot Posture index to put a number on the amount of forefoot abduction rather than just say too many toes.

Inhibition of the peroneal muscles

The concept of peroneal muscle inhibition has both intrigued me and confused me, yet I do see it clinically and see the results, but the lack of objective data does trouble me. I started this discussion to get a better understanding of it. I am not sure it did.

The concept is that there is some sort of inhibition of the peroneal muscles, particularly the peroneus longus and the muscle does not work as it should. This “weakness” can lead to a range of symptoms from functional hallux limitus (and its compensations), increased risk for ankle sprains, lateral foot pain and maybe Achilles tendon pain. Muscle testing will show a significantly weaker peroneus longus. Its not clear what it is that leads to this inhibition which without objective data to consider that is a problem.

Typically with a mobilization of the proximal and distal tibiofibular joint, you can see an almost immediate return to the strength of the peroneus longus. I have certainly seen that plenty of times clinically and have no doubt about its clinical usefulness. However, I really struggle to come up with a coherent explanation of how the inhibition was  caused and how the mobilization overcomes it. It you have something to contribute, please head over to Podiatry Arena and contribute your ideas in the thread on this topic.

The Supination Resistance Test

In the early days of the Clinical Biomechanics Boot Camps we spent a lot of time on the supination resistance test and the concept of supination resistance, as the concept was so new to so many, but as time went by less time was spent on it as the test has become so widely used and quite pervasive when it comes to prescribing foot orthotics.

The test was first described by Kevin Kirby, DPM and we have done a lot of work on it with a number of studies exploring the concept. Along with that research I used clinically and we did a lot of practical sessions on it in the boot camps – all of this lead to what I think was a good understanding of it and just how useful it was to use clinically when it came to the prescribing of foot orthotics in clinical practice. I think those who did the clinical biomechanics boot camps did get to agree with me just how important that the concept was for the prescribing of foot orthotics and understanding pathology. There are a lot of threads on Podiatry Arena on the topic that get updated regularly.

The supination resistance test is simply a test to estimate just how much force is needed to supinate the foot and then applying that knowledge to how much force is needed to come from the foot orthotic. If the force to supinate the foot is high, then the force needed from a foot orthotic needs to be high. No point using a soft flexible foot orthotic in those with a high supination resistance as the orthotic is probably going to do nothing. If the supination force is low, then a soft flexible foot orthotic is going to be adequate. Using a rigid inverted type of foot orthotic in a foot with low supination resistance is probably going to sprain the ankle.

For our research we used a device that we built to quantify it but that device really has no practical use in clinical practice, so the use of the hands and manually estimating is adequate. There are some devices on the market, such as the Keystone that can be used to put a number on it.

What I used to like saying to people who were unfamiliar with the test is to just do it. Get a feel for it. Find those feet that are high or low and see how that might relate to the pathology that the patient has. Get a feel for how people with different levels of supination resistance respond to different foot orthotic designs. You soon start to see patterns.

Volunteering at the parkrun

I hope no one from parkrun reads this!

The parkrun is a weekly 5k run held in over 2000 locations at 8AM on a Saturday morning all over the world (COVID restrictions permitting). I have run a few and volunteered at a lot. I mostly do the one here at Mullum Mullum in Mitcham. These events do not go ahead without the volunteers

You can read more on the parkrun here and here.

Why do I hope no one from parkrun reads this? I enjoy my Saturday morning interactions with the runners and walkers. I enjoy chatting with them. They have no idea of my interest and expertise in running, running injury and running shoes. I chat to them about what drives their shoe choices, how they managed with their injury, etc. It gives me insight into these issues. I do not generally give my advice. I like it that way. That is why I hope none of my new friends from the Mullum mullum park run see this post!

For those with an interest, please find a parkrun near you and give it a go at running it and helping out as a volunteer.

You may also find this book of interest:

Buy in Australia | UK | USA I Worldwide (free shipping)

Are foot orthotics active or passive physical therapies?

Within physiotherapy there has been a big trend to distinguish between active and passive treatments with the general considerations that active treatments are better and the evidence does generally link better outcomes coming from the active treatments. Passive treatments are generally those that are done to the patient such as manipulations, massage, TENS and dry needling. Active treatments are those that the patients does to themselves such as exercises.

Given this division within physiotherapy, the question comes up as to if foot orthotics come under the active or passive category. I assume the answer to this could be based on someone’s preconceived biases as they want them to be a passive treatments when active treatments are seen as better. I do not think foot orthotics come under either category. Arguments could be made either way. There are other types of treatments that do not fit into one or the other category either, so why would you want to try and put them into one or the other? Is there any point trying? If you need foot orthotics, you need foot orthotics. If you don’t need them, then you do not need them. Does it matter if they are considered active or passive treatments?

I do agree that active interventions are probably preferable for a whole lot of reasons that I will not get into here. That does not mean that there is anything wrong with passive treatments (but there is a lot wrong with some of them and others do not have a lot or any evidence supporting them). For example, what is wrong with self massage for plantar fasciitis with something like a PediRoller? Passive treatments are probably better options during the acute phase of an injury.

Posterior tibial tendon dysfunction or adult acquired flat foot or progressive collapsing foot deformity?

What should it be called? I have long been part of the school that thinks we should be sticking with the posterior tibial tendon dysfunction name as that is the one that has mostly stuck and the problem was considered one of the posterior tibial muscle no longer being able to do its job – it just made sense. Two things are starting to change my mind:

  1. The pathomechanical and other studies have shown there is a lot more to it than just the posterior tibial tendon.
  2. The confusion between posterior tibial tendon dysfunction and posterior tibial tendonitis is too common and leading to wrong treatment choices (especially in runners).

It is the later point that is getting more and more attention. They are not the same thing. Posterior tibial tendonitis is an overuse injury in active healthy people. Posterior tibial tendon dysfunction is a progressive flatfoot deformity in older, often overweight adults. Two totally different sets of symptoms; two totally different populations; two totally different sets of clinical features …. yet some think they are the same thing on a continuum and some mix the two up and use the same treatment interventions. Nope.

I now think we should be calling posterior tibial tendon dysfunction either adult acquired flatfoot or progressive collapsing foot deformity to avoid the confusion and better reflect the underpinning pathological process. This terminology of progressive collapsing foot deformity is the name that seems to be being used more frequently in the most recent literature on this problem.

On a light-hearted note…

With all the travel I used to do for the Clinical Biomechanics Boot Camps I took to having ‘bacon and eggs’ for breakfast once in every city I visited and posting a photo on Facebook. It was always a source of discussion about the breakfast and the travel. After doing it for so many years, I paid one of my girls to scroll through my Facebook feed and collect all the photos and put them together on its own website for a bit if fun: Breakfast of Champions.

Sadly the COVID restrictions have put the breaks on the travel, except for local travel I have not been able to update the site much with any new international cities.

Peroneal Tendinopathy is easy!

In my hands peroneal tendinopathy or tendonitis used to be a challenge. In the past I reckon I was close to a 100% failure rate in managing it. In the last 10 or so years I think I am now close to a 100% success in managing it. What changed? It was based on our research evidence. I talked about that in this blog post: Peroneal Tendonitis in Runners on my running research blog. It was pretty clear that almost everyone with peroneal tendinopathy had a lower than average supination resistance. That means the force needed to supinate the foot was low and as a consequence the peroneal tendons have to work harder, increasing the risk for tendinopathy. This also means that those with it need lateral wedging under the heel to decrease the loads in the tendon. That wedging actually leads to a substantial reduction in the forces that the tendon is subjected to, so hence the lateral wedging is a very and often is dramatically effective to manage peroneal tendonitis.

Yes, lateral wedging does try to pronate the foot more, but never had a problem with doing that. It did take a mindset change to get confident to start doing this 10 or more years ago, but I have not looked back. This is a perfect example of research informing and changing clinical practice.

This also means that a typically arch supporting medially wedged foot orthotic is going to increase the load on the peroneal tendon and is not going to be indicated. This also explains why I had almost a 100% failure on managing this in the past.

Also, of course, we do the usual load management approaches to this tendon once that reduction in load on the tendon with the wedge is done.

“Overpronation” …. oh no!

In social media, everyone is an expert on this. Opinions vary, but facts don’t, but all so often those opinions are being stated in the ignorance of the actual research evidence.

I have written so many times about this in so many places (eg here, here and here), so lets type it slowly and make it clear:

Firstly, there is no clear definition of “overpronation” which is why I generally put it in the “x”, but we all know it when we see it. Yes, pronation is normal, but we generally lack a clear definition of when that normal becomes too much. However, we do have normative data on the foot posture index (FPI), so there is some consensus as to what is normal and abnormal. I am pretty sure most of those posting in social media about “overpronation” have no clue what this normative data is or even what the FPI is that its based on is. This is also probably complicated that the division between normal and abnormal is most likely to be subject specific and mediated by many other factors, such as tissue capacity.

Secondly, yes there is something wrong with “overpronation”. Too many in social media keep saying that it is not a problem. Yes, there are studies that show its not and yes, there are studies showing that it is a problem. This also has to be interpreted in the context of how each study actually measured “overpronation”. When you get conflicting evidence you then need to turn to the systematic reviews and meta-analyses which assess the quality of studies and how much weight to give each of those studies. All those most recent reviews of the preponderance of that evidence have shown the same thing: “overpronation” is a problem; it is a risk factor for running injury. However, it is only a small risk factor, but it is still a statistically significant risk factor.

Thirdly, just becasue someone can show an example of someone who massively “overpronates” and does not have a problem is not evidence that it is not a problem. The video of Haille Gebrselassie (“the truth”) come to mind. This is no different to showing someone who has smoked cigarettes their whole life who did not develop lung cancer. Does that mean smoking does not cause lung cancer? People who use examples like that video of Haille Gebrselassie to support their case really should know better and are just showing their ignorance of causation and the actual scientific evidence and just what a risk factor is and how it works.

Fourthly, there are multiple causes of “overpronation” and if it needs to be dealt with, it is dealt with by dealing with that cause in that individual. Anyone who is advocating one particular treatment for “overpronation” really have no clue what they are talking about. There are multiple options, but the option that will only work is the one that is directed at the specific cause in each individual. You can tell how much someone in social media knows about this based on what they say you need to do to deal with it. One hit wonders are clueless, so ignore them.

Enough said … again.

The Clinical Importance of Navicular Drop and Navicular Drift

I am a big fan of teaching people how to measure the navicular drift and drop. However, the evidence is that for clinical use they are not that reliable, so that does limit the usefulness of these clinical tests in clinical practice.

Having said that, I still think we should be teaching how to do it, but in the context of the unreliability of them. The reason for this is that the concept behind navicular drift and drop does have implications for foot orthotic prescribing. What learning how to do the tests gives clinicians is an appreciation of the relative movements of the midfoot in the sagittal and transverse planes. Navicular drop measures the sagittal plane motion of the midfoot and navicular drift measures the transverse plane motion of the midfoot. Learning how to do the measurement of these two gives an appreciation of the relative motion of that midfoot in the sagittal and transverse plane. Once that appreciation and understanding is grasped, then there is probably no need to do the measurements on a routine basis in clinical practice. You can just observe it and note how much drop there is compared to how much drift there is. Are the about the same or is there more of one compared to the other?

My impression is that the amount of navicular drift should be about the same as navicular drop. If drop is greater, then that means that there is more movement in the sagittal place compared to the transverse plane. This means there is more arch collapse, when means that the foot orthotics need to have more support in the midfoot. If the drift is greater, then that means there is more movement in the transverse plane compared to the sagittal plane. This means that there is more movement of the midfoot medially rather than arch collapse. This means that foot orthotics need more medial and lateral support to control that midfoot transverse plane motion.

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