I touched on this during a recent chat with Matt Phillips on RunChatLive (catch it HERE if you missed it) and have had several messages about it since so thought I’d just milk the analogy as much as possible and put it all down in one place for those interested. It is of course just an analogy, and not completely perfect (counter points welcome).
The way foot orthoses are often framed as ‘arch supports’ or ‘rearfoot correctors/aligners’ (both historically and currently) is something that there is a rising argument for moving away from; primarily as it is not in keeping with any reasonable interpretation of the current evidence base regarding their mechanisms of effect. However, the case could be made for this hugely oversimplified (and erroneous) belief about them also being the reason that almost everyone on the planet has an opinion on foot orthoses, which they feel is equally valid to those of the experts who have spent careers studying in the field.
“They don’t work”
“They are a con – a waste of money”
“They don’t address the cause of the problem”
“A really good runner at my club said I need them/don’t need them”
Or perhaps this interaction:
A: “I have foot pain so my therapist prescribed me some custom made orthoses”
B: “You don’t need those! You just need Superfeet insoles from the internet”
A: “Really? Oh…”
Why are individuals far less likely to speak this way about medication? Likely because they know what they don’t know – the complex way drugs work on a biological level, the many many different groups and sub-categories of drugs, and the appropriate (or inappropriate) dosages for each in the context of the presenting disease (which they would also admit they do not understand).
A: “I have high blood pressure so my doctor prescribed me Enalapril tablets”
B: “You don’t need those! You just need Magnesium tablets from Holland & Barrett”
A: “Ok” *ignores opinion of B almost immediately*
So, what if we reframe foot orthoses in the same way… will we see behaviour change? At the very least we may get people thinking about the depth and complexity surrounding foot orthoses design and prescription which they are currently unaware of. And along the way we may also improve the way we implement orthoses usage in our clinics, the way we set expectations of those we issue them to, and the way we study them within our research projects in the future.
Different Drugs at Different Doses
There is a general appreciation for the categorisation of medication. There is not a tendency to look at 10 different tablets sitting on a desk and assume they are all identical. Most would appreciate that despite looking very similar in appearance the prescription of such things (i.e. which ones to issue or not issue, and at what dosage) will be disease specific.
However, there is a large tendency for people to treat all foot orthoses as if they are identical, and this is often what allows people to adopt the dichotomous positon of all orthoses being equal, and thus either ‘good’ or ‘bad’ (depending on the beliefs or biases held). When we consider the huge variance in materials that orthoses can be made from, the vast range of shell geometries possible, and the numerous modifications and additions that can be used in almost infinite combinations it is quite reasonable to suggest they are not unlike the desk of tablets.
If we were to read a study that said it investigated the use of an anti-hypertensive (such as Enalapril) in a group of individuals with raised blood glucose levels secondary to Diabetes, and it showed there was no significant positive effects it is likely that would it not be that surprising. Other than not using that drug for that specific reason clinically (which most would clearly not be doing anyway – and may even question why such a drug was used in the study), it is unlikely clinical practice would change at all. No-one would claim Enalapril was a terrible drug that was never needed for anyone; simply that it had limitations in what it could achieve.
However, I have not seen analogous reactions to foot orthoses studies. When studies have shown that devices of one particular design did not appear to have beneficial effects in a cohort with a specific pathology, the behaviour is very different. Rarely is there the consideration that perhaps it was the “wrong drug/dose for the task”. Many take the conclusions and allow them to completely influence their beliefs and paradigms of clinical practice. How often do you see people questioning why such an orthosis was used in a study? (Not enough maybe?)
Subject Specific Responses
When a group of individuals with the same complaint (e.g. a headache) all take an identical drug at an identical dose (e.g. 1000mg of Paracetamol), would we expect the outcome to be the same? What we often term ‘subject specific responses’ are the actual reality. Some may have the desired outcome (their headache recedes). Some may have no outcome at all (headache remains so they require a different drug). A small percentage may even have an adverse reaction (from the minor all the way through to anaphylaxis). Different physiological responses from different individuals to the same intervention.
The response to foot orthoses could also be viewed in this way. Some will experience a desirable and positive outcome, whilst others may have an indifferent response or even an adverse response (meaning they may require a different type of orthosis – a different drug/dose if you will – or perhaps they are not an appropriate candidate for such a device at all). This information should hugely colour the discussions has with potential recipients of devices before they are issued. The way practitioners set expectations, and the promises they make, or perhaps shouldn’t be making, are key here.
Therapeutic Window
With any drug if given at too low a dose there will be little to no effects. At too high a dose it is usually toxic (and the risk of adverse effects is greatly increased). The range in the middle where the risk:reward ratio is potentially optimum is often called the therapeutic window. The complexity here is that this window will of course be individual/person specific. A good question to ponder is how (or if) we can successfully identify this window clinically with respect to foot orthoses before they are issued.
When side effects are experienced with drugs then the dose may be altered (or the drug discontinued and/or changed for another). Adverse reactions to orthoses should be considered in the same way, and it is often the feedback following initial issue of them and trial period of usage that allows this ‘titration’ and refinement.
Duration of Use
Some drugs are given for short courses (e.g. antibiotics for an ear infection), whereas others for longer courses (e.g. Prednisolone following a respiratory episode) or even as a life sentence (e.g. low dose aspirin following a cardiac episode). Foot orthoses are considered by many to be life sentences, which when viewed through the lens of the historical belief that they were ‘realigning the skeleton’ or ‘correcting deformity’ sort of makes sense. However, it seems appropriate to adjust this belief given what we now understand about foot orthoses. For the majority they may be far more likely to be a short to medium term intervention rather than a life sentence.
Summary [TL;DR]
Most appreciate (even in the lack of understanding) the complexity of drugs and they way they interact with humans, the sensible approach a professional takes when choosing an appropriate drug at an appropriate dose for a given disease/pathology and that not all drugs work for all people/problems all of the time. Foot orthoses are not often viewed in this same way, but there is a reasonable argument that doing so is a more appropriate way of considering these seemingly “simple arch supports” both now and moving forward into the future.
