What is Spinal Stenosis – Not enough space in this spine for both of us

Welcome back amazing nerds.

Today’s text aims at continuing to inform about the most common musculoskeletal complaint: back pain. More specifically, it is about a pathology that can be linked to back pain, can sound really scary, and sometimes is not well understood even by healthcare professionals. I’m going to be discussing spinal stenosis. I will start by covering what it is and what can lead to it happening in our bodies.

The term stenosis basically means narrowing, so spinal stenosis means narrowing of the spaces in our spine where the nerves, blood vessels, and the spinal cord pass through (Urits et al, 2019; Wei et al, 2021). This has the potential to cause compression and/or ischemia of these structures (Ammendolia et al, 2022): what is commonly called a “trapped nerve”. This could happen at different levels of the spine (McCartney et al, 2018; Urits et al, 2019). This narrowing often is caused by changes that are usually grouped into what is called degenerative changes, or osteoarthritis, which can include disc herniation, osteophyte formation, or ligament thickening but in very rare cases can be caused by a more concerning mass occupying the available space for the previously mentioned structures (McCartney et al, 2018; Wei et al, 2021).

Common symptoms of spinal stenosis include pain around the affected spinal area that can irradiate to arms or legs, one or both sides, following the distribution of a dermatome, depending on the level of the stenosis, as well as pins and needles and/or numbness (Ammendolia et al, 2022; Hartvigsen, 2018; McCartney et al, 2018; Urits et al, 2019). A particular group of symptoms that is very common and often limits someone’s ability to walk is something called neurogenic claudication, which is a clinical presentation involving buttock or leg pain, pins and needles, numbness, weakness or fatigue, independent of back pain, that worsens with standing or walking and improves with rest and/or lumbar spine flexion (Ammendolia et al, 2022; Hartvigsen, 2018). See, flexing your spine isn’t really as bad as it is often made to be. It is also important to note that weakness is not as common as sensory changes, but can still be present and usually matches a specific myotomal depending on the level of the spine affected (McCartney et al, 2018).

Currently, the expert consensus for the diagnosis of spinal stenosis requires that both the signs and symptoms matching the condition are present and that there is confirmation of narrowing of either the foramina (holes on the side of the spine) or the spinal canal at the level that correlates with symptoms (Hartvigsen, 2018). But what exactly can we see on imaging? Let’s look at some of the more common findings.

Disc Herniation

This is what is commonly called a ‘slipped disc’, which is basically the worst name you can give as it in no way describes what is happening with our intervertebral disc as these do not slip out of place. Our spines aren’t Jenga towers. So, if you’re reading this, please do me a favour – never again use that term.

What actually happens in a disc herniation is that part of the gel-like substance that makes ups the nucleus of the disc starts pushing through the outer layers of the intervertebral disc, sometimes even oozing out (Fardon et al, 2014; Yamaguchi and Hsu, 2019). In simple terms, part of the disc bulges. In some instances, it can happen due to some forms of trauma, but more often than not it happens as part of normal age-related changes (Yamaguchi and Hsu, 2019).  I use the term normal because if we look across people without any sort of back pain or any spine symptoms, the probability of them having a disc herniation on imaging without being aware ranges from 50% on 40-year-olds to 84% on 80-year-olds (Brinjikji et al, 2015). Different terms like ‘disc protrusion’, disc extrusion’, and ‘disc sequestration’ are all different magnitudes of disc herniations as classified by the Combined Task Force (Fardon and Milette, 2001; Fardon et al, 2014).

Summarising, the data shows that disc bulges are common, normal things and not catastrophic injuries that will leave you paralyzed. And they may not need special treatment as our body can on its own improve and sometimes even completely reabsorb the disc herniation, with the worse-looking disc bulges being the ones more likely to improve (Chiu et al, 2015). And don’t trust anyone who says they will be pushing the disc back in using their hands or a certain exercise – there is no evidence that is possible.


This hard-to-pronounce term is used to describe when one vertebra moves out of alignment with the one under it (Kreiner et al, 2016; Samuel, Moor and Cunnigham, 2017). This is the only condition in which your vertebrae move out of place, despite what some pseudo-scientific professions would like you to think, and before you run to call a surgeon to scan or operate on your back because of your back pain, let’s first understand how spondylolisthesis is classified and its clinical relevance, or lack thereof.

Spondylolisthesis is somewhat common, with its prevalence ranging between 19.1% and 43.1% in the general population, with its prevalence being higher in older adults (Bydon, Alvi and Goyal, 2019)

Spondylolisthesis is classified between Grade I and Grade V through the Meyerding classification depending on the percentage of misalignment of the vertebrae, however, so far, the evidence points to there not being an association between clinical symptoms and progression of misalignment on scans (Akkawi and Zmerly, 2021). Although spondylolisthesis can lead to back pain and spinal stenosis, unless some very specific neurological symptoms are present, spondylolisthesis is commonly benign and not having specific treatments does not lead to further progression of the misalignment or of the clinical symptoms (Wei et al, 2021).

Yes, you read that right. Even in a condition where a vertebra is misaligned, the amount of misalignment does not correspond to the symptoms you get in terms of pain or neurological changes. Isn’t it amazing how robust and adaptive our body is? And no, we don’t that have any data showing that some will be able to re-align the vertebrae using their hands or weird gadgets or tools. The treatments often offered by chiropractors and osteopaths are pseudo-scientific treatments for pseudo-scientific problems and there is no evidence they are beneficial for spondylolisthesis.

These are the most common pathologies that can lead to some narrowing in some parts of our spine. There are other conditions that can also lead to this, but they are very, very rare even something like a spinal fracture will only be present in less than 1% of people when they have back pain following a fall (Finucane et al, 2020). And something really serious like cancer is present in less than 1% of cases of back pain (Finucane et al, 2020). So, despite what Google may tell you, unless you have a very specific medical history, your back pain is 99% unlikely to be cancer or anything serious.

However, remember that these texts have the goal to inform, not diagnose, so if you’re in doubt, book an assessment with a qualified physiotherapist. Considering this, I hope this has helped you understand a bit more about spinal stenosis, the different things that can lead to it, and how common it is. In the next couple of texts, I will be exploring if scans are helpful and how this condition is usually managed.

I hope to see you amazing nerds in the next one,

The Physiolosopher


Akkawi, I., & Zmerly, H. (2021). Degenerative Spondylolisthesis: A Narrative Review. Acta Biomedica, 92(6). https://doi.org/10.23750/abm.v92i6.10526

Ammendolia, C., Hofkirchner, C., Plener, J., Bussières, A., Schneider, M. J., Young, J. J., Furlan, A. D., Stuber, K., Ahmed, A., Cancelliere, C., Adeboyejo, A., & Ornelas, J. (2022). Non-operative treatment for lumbar spinal stenosis with neurogenic claudication: An updated systematic review. In BMJ Open (Vol. 12, Issue 1). BMJ Publishing Group. https://doi.org/10.1136/bmjopen-2021-057724

McCartney, S., Blagg, S., Baskerville, R., & McCartney, D. (2018). Cervical radiculopathy and cervical myelopathy: Diagnosis and management in primary care. British Journal of General Practice, 68(666), 44–46. https://doi.org/10.3399/bjgp17X694361

Brinjikji, W., Luetmer, P. H., Comstock, B., Bresnahan, B. W., Chen, L. E., Deyo, R. A., Halabi, S., Turner, J. A., Avins, A. L., James, K., Wald, J. T., Kallmes, D. F. and Jarvik, J. G. 2015. Systematic Literature Review of Imaging Features of Spinal Degeneration in Asymptomatic Populations. Am J Neuroradiol, 36(4),  pp.811-16 DOI: https://doi.org/10.3174/ajnr.A4173

Bydon, M., Alvi, M. A., & Goyal, A. (2019). Degenerative Lumbar Spondylolisthesis: Definition, Natural History, Conservative Management, and Surgical Treatment. Neurosurgery Clinics of North America, 30(3), 299–304. https://doi.org/10.1016/j.nec.2019.02.003

Chiu, C. C., Chuang, T. Y., Chang, K. H., Wu, C. H., Lin, P. W., & Hsu, W. Y. (2015). The probability of spontaneous regression of lumbar herniated disc: A systematic review. In Clinical Rehabilitation (Vol. 29, Issue 2, pp. 184–195). SAGE Publications Ltd. https://doi.org/10.1177/0269215514540919

Fardon, D. F., & Milette, P. C. (2001). Nomenclature and Classification of Lumbar Disc Pathology. In SPINE (Vol. 26, Issue 5).

Fardon, D. F., Williams, A. L., Dohring, E. J., Murtagh, F. R., Gabriel Rothman, S. L., & Sze, G. K. (2014). Lumbar disc nomenclature: Version 2.0 Recommendations of the combined task forces of the North American Spine Society, the American Society of Spine Radiology and the American Society of Neuroradiology. In Spine Journal (Vol. 14, Issue 11, pp. 2525–2545). Elsevier Inc. https://doi.org/10.1016/j.spinee.2014.04.022

Hartvigsen, J., Hancock, M. J., Kongsted, A., Louw, Q., Ferreira, M. L., Genevay, S., Hoy, D., Karppinen, J., Pransky, G., Sieper, J., Smeets, R. J., Underwood, M., Buchbinder, R., Cherkin, D., Foster, N. E., Maher, C. G., van Tulder, M., Anema, J. R., Chou, R., Cohen, S. P., Menezes Costa, L., Croft, P., Ferreira, P. H., Fritz, J. M., Gross, D. P., Koes, B. W., Öberg, B., Peul, W. C., Schoene, M., Turner, J. A. and Woolf, A. 2018. What low back pain is and why we need to pay attention, The Lancet, 391(10137), pp. 2356–2367. doi: 10.1016/S0140-6736(18)30480-X.

Kreiner, D. S., Baisden, J., Mazanec, D. J., Patel, R. D., Bess, R. S., Burton, D., … Williams, K. D. (2016). Guideline summary review: an evidence-based clinical guideline for the diagnosis and treatment of adult isthmic spondylolisthesis. Spine Journal, 16(12), 1478–1485. https://doi.org/10.1016/j.spinee.2016.08.034

Samuel, A. M., Moore, H. G., & Cunningham, M. E. (2017). Treatment for Degenerative Lumbar Spondylolisthesis: Current Concepts and New Evidence. Current Reviews in Musculoskeletal Medicine, 10(4), 521–529. https://doi.org/10.1007/s12178-017-9442-3

Urits, I., Burshtein, A., Sharma, M., Testa, L., Gold, P. A., Orhurhu, V., Viswanath, O., Jones, M. R., Sidransky, M. A., Spektor, B., & Kaye, A. D. (2019). Low Back Pain, a Comprehensive Review: Pathophysiology, Diagnosis, and Treatment. In Current Pain and Headache Reports (Vol. 23, Issue 3). Current Medicine Group LLC 1. https://doi.org/10.1007/s11916-019-0757-1

Wei, F. L., Zhou, C. P., Liu, R., Zhu, K. L., Du, M. R., Gao, H. R., Wu, S. da, Sun, L. L., Yan, X. D., Liu, Y., & Qian, J. X. (2021). Management for lumbar spinal stenosis: A network meta-analysis and systematic review. In International Journal of Surgery (Vol. 85, pp. 19–28). Elsevier Ltd. https://doi.org/10.1016/j.ijsu.2020.11.014 Yamaguchi, J. T., & Hsu, W. K. (2019). Intervertebral disc herniation in elite athletes. In International Orthopaedics (Vol. 43, Issue 4, pp. 833–840). Springer Verlag. https://doi.org/10.1007/s00264-018-4261-8

Socrates – part 2: Searching for the essence

Welcome back awesome nerds. This is the second part of my study of Socrates, where I’ll mainly focus on his philosophical ideas. If you want to know more about Socrates’ history and how much of a Chad he was, please go read the first part.

Without further delay, let’s explore the philosophical ideas of this prominent figure. For Socrates the search for knowledge was very important.  He considered knowledge to be the most important thing in life, as he equated knowledge with virtue itself (Adamson, 2014; Russel, 1946). His reasoning was that you needed knowledge about something to do it well, and when you do something well, you are doing it virtuously (Adamson, 2014).

Due to this, Socrates held the doctrine that no one does something wrong knowingly (Adamson, 2014; Kenny, 2010; Russel, 1946). No one will think something is good and then choose not to act in that way. If someone acts wrongly is because they lack knowledge: they fail to see that even though they may have some short-term benefit, in the longer term that action is not good for them. (Adamson, 2014; Kenny, 2010). It follows that, in order to act well, we simply need to have the knowledge of what is good and what is bad, this knowledge being virtue (Kenny, 2010). Following his reasoning, we can understand why Socrates gave such importance to being able to define virtues (Adamson, 2014; Kenny, 2010; Russel, 1946).

In his search for the definition of virtue, we can see Socrates’s method of philosophy. Firstly, when questioning people, he would try to go from particular cases where virtue could clearly be identified and through these reach more general characteristics that were common between all virtues, but also not present in any other things beyond virtues (Kenny 2010). By doing this, Socrates would be utilising inductive arguments (Kenny, 2010). In case you have forgotten since I mentioned in my first text on philosophy, inductive reasoning is precisely when we devise a theory starting from several particular observations (Bowling, 2014; Sim, 2002).

In other words, Socrates tried to find the essence of virtues, as he argued that unless we have this, we won’t be able to identify the properties that belong to virtues, such as their usefulness, nor will we be able to identify if someone is acting virtuously when taking a certain position in an ethical dilemma (Kenny, 2010). This search for the essence of something has been massively influential, still being used by some philosophers as the framework for true knowledge (Kenny, 2010). However, it has also been contested recently as some recent philosophers argue that certain topics studied by philosophy don’t necessarily have an essence, for example language in its many forms (Kenny, 2010).

We can argue that Socrates’ reasoning is not entirely true, as someone acting in a way that is considered morally better or worse may not be just down to knowledge. There are situations where we may have all the knowledge available within human limitations about the circumstances of that situations, but how to act in a morally correct way may still evade us. A good example of this is the trolley problem and its many versions. However, Socrates is the first philosopher to focus on virtue in such a systematic manner and develop a logical approach to better understanding it.

With the aim of reaching these definitions and increasing his understanding of virtue, Socrates started questioning those considered knowledgeable, as in the same way that an expert carpenter can explain to you in detail how a shoe is made, someone who is knowledgeable and thus virtuous, will be able to tell you in detail the details involved in having virtue, starting by explaining what virtue is (Adamson, 2014). This reasoning lead Socrates to the comparison of virtue with forms of expertise, as those needed in certain crafts such as carpentry or shoemaking, or as in a scientific skill such as geometry (Kenny, 2010). He thought both virtue and skill expertise to be human characteristics that are both acquired as opposed to being innate, both are valued and beneficial to those who possess them, as the more virtuous or skilled we are the better we are likely to do in life (Kenny, 2010).

This particular way of searching for knowledge is known as dialectic and, despite Socrates not being credited with it, he used dialectic so much that it is often referred to as the ‘Socratic method’ (Adamson, 2014; Russel, 1946). Interestingly, the dialectic method would then methodologically complete Socrates’ search for knowledge. The dialectic method is mostly useful for questions for which we already have the facts but still haven’t reached a satisfactory answer due to not analysing these well or by an error of logic (Russel, 1946). This is an example of deductive reasoning (Russel, 1946), which, just in case you have also forgotten since (hyperlink), is when we test a theory or definition that we have developed from general principles to see if it survives scrutiny (Bowling, 2014; Sim, 2002). This type of reasoning is not useful when we are trying to answer questions that require us to obtain new facts, such as those often researched in physics or chemistry, but it well suited to answer the type of ethical questions that Socrates was occupied with (Russel, 1946).

Still Socrates continued to be influential, his values and actions influencing not only Plato, but other schools of philosophy. The Stoics would take on the belief that virtue is the supreme good and that our own virtue cannot be touched by external factors (Adamson, 2014; Russel, 1946). The Cynics would take on Socrates loathe for material goods, which lead to him walk barefoot and in old clothes all year long factors (Adamson, 2014; Russel, 1946).

But now we come to the time for you to reflect. Do you think virtue and knowledge are one and the same?

Would enough knowledge allow us to live the most virtuous of lives?

Do we need to have a complete and un-flawed definition of something to be able to understand it in a pragmatic way?

I hope to see you amazing nerds in the next text,

The Physiolosopher


Adamson, P. 2014. Classical Philosophy: A history of philosophy without any gaps, Volume 1. 1st edition. Oxford University Press: Oxford.

Bowling, A. Research Methods in Health – Investigating health in health services. 2014, fourth edition. Open University Press. Berkshire, England

Kenny, A. 2010. A New History of Western Philosophy: In Four Parts. Reprint Edition. Oxford University Press: Oxford.

Russel, B. 1946. History of Western Philosophy. Routledge – Taylor and Francis Group: New York.

Sim, J., Wright, C . 2002. Research in Healthcare – Concepts, Designs and Methods. Second edition. Nelson Thornes Ltd. Cheltenham, United Kingdom

Socrates – part 1: He who knows nothing

Welcome back to our shared journey through philosophy over the years. This time we will be witnessing history! I am happy to point out that we have concluded our journey through the Pre-Socratic philosophers, and we have reached the man, the myth, the legend himself: Socrates.

If my introduction wasn’t enough to highlight his important, I’ll also point out that its not everyone that reaches the standard of having a whole era of history named after you. The fact that all philosophers we have covered so far, despite their revolutionary ideas, are grouped into the “Pre-Socratics” shows how Socrates’ arrival into the philosophy scene inaugurated a whole new era (Kenny, 2010). Socrates’ influence was indeed great to the point that even in modern days some consider him to be the most influential and famous philosopher ever (Adamson, 2014).

But who was Socrates, why is he so important and why should you care?

Straight away, in trying to answer this question, his story grabs our interest. Socrates didn’t actually write anything (Adamson, 2014), thus most of what we know of him comes from the writings of two of his most well-known students: Xenophon and the also famous and also philosopher, Plato (Russel, 1946).

Let’s start by looking at the facts that scholars have reached more certainty about. We know Socrates wasn’t an imaginary figure but an actual person, because besides his two students, he was also referenced in the writings of others, including prominent figures in Athenian society, such as the playwright Aristophanes who made Socrates part of his play The Clouds (Adamson, 2014; Kenny, 2010).

We also know that Socrates was born in Athens, around the year 469 B.C., and he is commonly described as spending his days in the marketplace, surrounded by Athenian youths, with whom he would have conversations and debates, through these teaching them philosophy without requesting payment (Adamson, 2014; Kenny, 2010; Russel, 1946).

This, however, would be one of the things that would lead to his tragic end. Another certainty about Socrates was that at the late age of 70, he was taken to court under the charges of worshipping gods that differed from those of the state, engaging in sophistry by making arguments fit what pleased his view, and corrupting the youth by teaching them both of these things (Adamson, 2014; Kenny, 2010; Russel, 1946). However, the plot thickens, as there is said to be another nefarious reason for Socrates’ prosecution: without extending myself beyond the goals of this text into the geopolitical situation of Athens at the time, in simple terms, Athens was then ruled by a group of questionable characters dubbed the ‘Thirty Tyrants’, who Socrates disobeyed as he thought their orders unethical, at the same time as having some of his former students within said ‘Thirty Tyrants’ and refusing to join their political opposition in overthrowing them (Adamson, 2014; Kenny, 2010; Russel, 1946). Simply put, Socrates managed to annoy everyone important in Athens.

I’ll get to what happened during that trial shortly, but first I need to mention another of the most commonly described facts about Socrates: the prophecy of the Oracle of Delphi. It is said that one of Socrates friends went to ask this oracle if there were any person wiser than Socrates, to which the oracle answered there were none (Adamson, 2014; Kenny, 2010; Russel, 1946). Now, Socrates, particularly when described by Plato, was known for often saying that he knows nothing and the only wisdom he possessed was knowing that he knew nothing (Adamson, 2014; Russel, 1946).

Considering this, you can see how he was initially confused by the answer given by the oracle. Still, he maintained the belief that the gods could not lie, and to try to solve his confusion, he started going around questioning people popularly considered knowledgeable at the time, such as politicians, poets, and artisans, with the aim of finding someone wiser than him who could give him an answer (Adamson, 2014; Kenny, 2010; Russel, 1946).

Disappointingly, Socrates did not find anyone wiser than him. This however enlightened him: he understood that he was considered the wisest by the oracle not because like all others he knew nothing, but because he knew that he knew nothing (Russel, 1946). This further fuelled his search for knowledge as he interpreted this as being given a message from god to search in himself and others for true knowledge, which was his justification for going around Athens questioning people to wake them up to their ignorance (Russel,1946).

You may start to think he was bold in his defence, but that would be an understatement. Because he didn’t see himself as guilty in any way, like the Chad he was, when facing the death penalty, during his defence speech Socrates questions the moral character and intelligence of both his prosecutors and everyone in Athens; states that he won’t be harmed by his prosecutors ‘…for a bad man is not permitted to injure one better than himself.’; argues that being killed would be a loss to the Athenian state; states that because he his virtuous he would never be foolish to the point of corrupting his fellow citizens intentionally and if he his doing so unintentionally, he should then be educated instead of judged (Russel, 1946). Unsurprisingly, annoying everyone does get you the death penalty.

These were Socrates’ final words in court: “If you think that by killing men you can prevent some one from censoring your evil lives, you are mistaken; that is not a way of escape which is either possible or honourable; the easiest and noblest way is not to be disabling other, but to be improving.” (Russel, 1946). He died in 399 BC., following drinking a cup of the poisonous plant hemlock (Adamson, 2014).

Summarising, Socrates was someone very sure of his own qualities, who strictly followed certain moral principles, didn’t care about worldly success, believed to be under divine guidance and held the doctrine that thinking clearly is the most important thing in leading our lives the right way (Adamson, 2014; Russel, 1946).

Now you know who this absolute mad lad was and how he stayed true to his values until death. I find his history quite inspiring. It’s not easy to be this true to ourselves, particularly when this is threatening our own life.

In the next text, I will explore in more detail the philosophic contributions of Socrates.

I hope to see you amazing nerds in the next text,

The Physiolosopher


Adamson, P. 2014. Classical Philosophy: A history of philosophy without any gaps, Volume 1. 1st edition. Oxford University Press: Oxford.

Kenny, A. 2010. A New History of Western Philosophy: In Four Parts. Reprint Edition. Oxford University Press: Oxford.

Russel, B. 1946. History of Western Philosophy. Routledge – Taylor and Francis Group: New York.

Bias in Research: Not all studies are created equal

Hello again. In the last post, I explored some of the more common biases that affect our perception of what we experience in our daily clinical practice, and how these limit the conclusions and generalisations we can make from our clinical experience. If you haven’t already, I recommend reading it here before starting this one. Considering this, I also ended by saying that all forms of information created by humans will have some degree of our biases reflected onto them, including research studies.

Even though I’m a convict advocate for science, I will still be analysing it critically, as it is important to be aware of the flaws that can be present in research studies because first, all studies are at some risk of bias (Kamper, 2018(a)); and second, this scientific evidence, as a key component of evidence-based practice, is still the best way for us to gain knowledge about different elements of healthcare practice, be it diagnostic tests, prevalence of conditions or treatment effectiveness. In addition to this, as I previously mentioned in this text, the first epistemological principle of evidenced-based practice states that not all evidence is created equal, and we need to be able to differentiate between which studies are better and which ones are worse.

How do we do this? Exactly by trying to identify these different types of bias that may be present in scientific evidence. When a study as got a lot of bias in it, it is more likely to lead to an inaccurate estimation of what they are trying to measure, limiting the conclusions and knowledge we can gain from that study (Kamper, 2018(a)).

This is not an easy thing. There are a lot of studies on the same topic, some of them with completely opposite conclusions. It might look that when applied by some researchers, one treatment works amazingly, but when the same treatment is applied next week by different researchers, it’s not beneficial anymore. This is a nightmare because clinical practice involves collecting information from various sources and applying it to reach a diagnosis or decide on a treatment (Kamper, 2018(a)). But, knowing about biases in research and how they affect results allows us to better assess the evidence we read, because by identifying which biases are present, or not, we can then understand which information we should give more or less weight to. Now that I’ve explained why being aware of them is useful, lets actually explore some of these biases.

Attrition Bias

It is quite common that in a study, particularly in those that run for a longer period of time, for there to be participants who stop showing up or answering the questionnaires they are sent. The problem with this is that is not possible to know what that person’s response to the intervention has been so far (Kamper, 2018(a)).

This could make the data gathered at the end of the study less accurate depending on factors such as the number of participants who completed the study, the number of participants who have left each group, how comparable are the participants who left and those who completed the study (Kamper, 2018(a)).

This bias can be tackled by trying to ensure that more than 85% of the initial participants are followed up on, as well as performing something called an ‘intention-to-treat analysis’ (Kamper, 2018(a)). This means analysing all the available data of people that were initially divided into of the groups, independently of if they complete the study or not (Bowling, 2014).

Detection Bias

When conducting a study, it is often the case that researchers want the study to show that their intervention as the effect they theorized and believe it would have (Kamper, 2018(a)). This preference of researchers may lead to them somewhat change how they measure or record outcomes, consciously or unconsciously.

For participants, this will mainly affect the outcomes they self-report on, leading for example to report doing worse than they actually did if they didn’t get the intervention they thought was better (Kamper, 2018(a)).

Both of these factors will then create bias in the results obtained in that study. In order to reduce this, what is called ‘blinging’ is applied. For participants, this means making the intervention applied to participants in the control group appears as beneficial as the one in the experimental group and not letting participants know which they are receiving (Kamper, 2018(a)).

For researchers, blinding can be achieved through the person collecting and/or evaluation the data obtained not being the same person applying the intervention and not knowing from which group the data was collected from (Kamper, 2018(a)).

Performance Bias

Similar to before, often researchers may want the study to show that the intervention is more effective, and the participants are likely to want to be in the study group that receives that intervention (Kamper, 2018(a)).

Because of this, the researchers may not deliver the two interventions with the same confidence or enthusiasm. The participants, on the other hand, may be disappointed if they’re not allocated to the group of their preference and not really put as much effort into following the instructions they are given (Kamper, 2018(a)).

This type of bias is overcome in a similar way to detection bias, ensuring that both treatments in the control and experimental group look equally beneficial, as well as not allowing the person assessing the collected outcomes to know which group they come from (Kamper, 2018(a)).

Reporting Bias/Publication Bias

In the world of research, studies that indicate an association or a positive effect are more likely to be selected for publication compared to those that show no effect or a negative one, despite the later two also adding valuable knowledge. As a consequence, this may make researchers more likely to, consciously or unconsciously, exaggerate their results or conclusions to show an effect (Bowling, 2014).

Over time this can lead to there not being accurate knowledge available on a certain topic, as in an attempt to be selected by publishers, most studies will not give us information that matches what is actually happening (Bowling, 2014).

This is a difficult bias to overcome, as that would likely mean changing the whole system through which research gets funded and selected for publication.

Selection Bias

Whenever a study is being conducted, there needs to be a number of people participating in the study. We can’t just simply test everyone in the world – it’s very impractical. So we have to select a sufficient number of people to be the sample of that study, and often we then have to again select between the people on our initial sample to divide into the different groups our study may involve, this often being the experimental group and the control group. But what happens if the researcher who selects the people and divides them between group does so based on their own preference? Because they want to study to be successful, they may only allocate to the experimental group, the people that appear more likely to benefit. Or they may select the people that appear nicer, all to be in the same group they going to assess – after all the researcher is going to have interact with them a lot, may as well make it pleasant. Sometimes, we also select people based on an unconscious judgement, so even without doing it on purpose, we could end up with study groups with considerable differences in characteristics between them. Because of this, any measurements or assessment we make, are likely to biased and not be applicable to the general population (Kamper, 2018(a)).

To reduce this type of bias, the best practice in studies is to randomize the allocation of participants between groups (Kamper, 2018(a)), with it being good practice for the authors to mention this in the text.

Quick note that this is in no way an exhaustive list, as different types of study may present different types of bias particular to their design that I have not included here.

Scientific research was developed with the aim of reducing the bias that our minds are prone to when observing and interpreting the world. However, research itself is created and applied by these same biased minds, thus leading to some bias becoming present. This doesn’t mean we can’t trust scientific research. It means that we must remain critical and be aware that theses biases exist. By doing this we understand that not all studies are equally relevant for giving us knowledge about certain topics and we can focus more on the information from the studies that are less biased (Kamper, 2018(a)).

I’ve heard both colleagues and members of the general public comment that scientists keep changing their mind all the time about what is good and what is bad, particularly when it comes to health. Often this is used as a way of dismissing evidence that conflicts with their current beliefs or way of acting, but that is another conversation. To me, this view highlights that the person saying they consider the conclusions of all studies to have the same level of accuracy and importance, showing a lack of ability to critically analyse information.

This is particularly problematic in clinical practice, as evidence-based practice requires the clinician to include in their reasoning process the careful examination of the type and magnitude of biases that inevitably are present in both clinical experience and research (Kamper, 2018(b).

Nothing that is created or interpreted by humans is free of bias. But I hope this post has provided you with some help on how to work around this and improve your ability to learn.

Never stop your search for knowledge. See you in the next one.

The Physiolosopher.


Bowling, A. Research Methods in Health – Investigating health in health services. 2014, fourth edition. Open University Press. Berkshire, England

Kamper, S. J. (2018 (a)). Engaging with research: Linking evidence with practice. Journal of Orthopaedic and Sports Physical Therapy, 48(6), 512–513. https://doi.org/10.2519/jospt.2018.0701

Kamper, S. J. (2018(b)). Bias: Linking evidence with practice. Journal of Orthopaedic and Sports Physical Therapy, 48(8), 667–668. https://doi.org/10.2519/jospt.2018.0703

Bias in Clinical Experience: Good intentions pave the road to mistakes

Hello again. In this post I intend to continue my exploration of why we need to understand the scientific method, why we need to inform our practice in research papers and how we can balance this with our personal/clinical experience in daily practice in a way that is beneficial to our patients.

If you haven’t already, please check my two-part introduction to evidence-based practice, starting here and then here. In these two texts, I have briefly covered the history and definition of evidence-based practice, what elements constitute it and how the funnel model helps us apply evidence to form useful knowledge.

In the first part, I also argued why what we experience with our own two eyes and ears during daily practice, although important, may not be enough to ensure we are doing the right thing to help the people who put their health in our care. A key element in this was the concept of bias, which is exactly the topic I want to focus on in this text.

I just want to make a brief disclaimer that, despite what may be frequently perceived, evidence-based practice does not dismiss clinical experience. It actually aims to better integrate research evidence, clinical experience, and expertise, as well as patient’s preferences and circumstances (Finch, 2007; Kamper, 2018(a); Meira, 2020; Sacket et al, 1996). With this aim, evidence-based practice challenges clinicians to accept there may be flaws to their reasoning and identify their own biases (Kamper, 2018(a); Sim and Wright, 2002).

To show that this is something quite normal, I’ll start with some of my own biases:

  • Strength training is one of the most important forms of exercise we should all do.
  • Coffee is healthy and good for us.
  • Video games are not a bad hobby.
  • In clinical practice, listening to and understanding patients is far more important than we do to them.

I’ve checked and after this, I still have all my limbs attached, I haven’t lost my job, the world hasn’t ended and more importantly, all my books and video games haven’t spontaneously combusted. That’s reassuring. But it shows that this humbling process isn’t harmful, even when I identify that some of the things I’ve listed may end up being wrong or that some of you may disagree with them.

But let’s ask: why is bias relevant to us?

As I explored in the previous posts, biases are a form of problem-solving process that our minds use, called Heuristics (Monteiro et al, 2020; Richarson, 2014; Saposnik et al, 2016). They are mental shortcuts that make our decision-making a bit simpler and more energy efficient. However, due to being quicker, we end up not spending as much time analysing information, thus making more mistakes (Phua, Fams, and Tan, 2013).

 If we ask an epidemiologist what is the definition of bias, they would say something like “a systematic deviation of the sample parameter estimate from the population value.” (Kamper, 2018(b)). Even though we’re all nerds here (c’mon, you’re spending your free time reading a text about evidence and critical thinking. Don’t deny it, you’re awesome), that’s a lot of big words.

Using more common language and applying it to the context of clinical observation, bias can be defined as “a difference between the results we see and what is actually happening” (Kamper, 2018(b); Sim and Wright, 2002).

To better help us understand, let’s look at some of the biases that are more common to occur when we try to interpret our personal and clinical experiences from day-to-day practice.

Confirmation bias

Imagine a physiotherapist who believes they are good at their job and that they have their patient’s best interests always in consideration. If not the first part, most of us will likely see ourselves reflected in the second part of that statement. And there is nothing wrong with that.

However, after further studying the human man, we have learned that we tend to, unconsciously, pay more attention to information that supports our beliefs or preconceptions, while simultaneously both interpreting ambiguous information as confirming our beliefs and ignoring information that refutes or contradicts said beliefs (Kamper, 2018(a); Monteiro et al, 2020).

This being the case, how do you think this will affect the above physiotherapist’s remembering of how their treatments affected their patients?

Evaluation apprehension bias

When someone is being tested, such as during any kind of clinical assessment, they may feel anxious to a certain degree. This can lead to them to try to answer or behave as they believe is expected by the assessor, instead of how they would normally (Bowling, 2014).

How do you think this will affect the results of the assessment?

Interviewer bias

When assessing or interviewing someone, we can unconsciously ask leading questions or express ourselves to be a certain type of clinician or person. This in turn will influence how someone will answer our questions during assessment or subsequent follow-ups. (Bowling, 2014)

Observer bias

Generally, due to our perception of things and way of thinking being affected by our beliefs and emotions, as well as some degree of variation every time we do the same thing, there are differences in how something really happened and how we perceived it as happening (Bowling, 2014; Phua, Fams and Tan, 2013).

Recall or Availability bias

We all have the tendency to quickly forget the more common events we see but remember very well the out-of-the-ordinary events, such as when something goes really well, or really badly (Bowling, 2014; Kamper, 2018(a)).

In our clinical practice, this leads to us basing our future decisions on those patients who did very well or very badly, instead of those with a more average, but also more frequent, outcome (Kamper, 2018(a)).

Selection bias

When working with our patients, the characteristics of those patients will be affected by things such as our geographical area, not only because of the geographical terrain, but also the socio-economic and political context of that area. Because of this, the characteristics of our own patients may differ from that of the wider population with that same condition or care needs. Because of how selective our patient group is as a result of this, we can’t really generalise what we observed with them to the rest of that population (Kamper, 2018(a)).

In addition to these specific documented biases, there are other issues we may come across that lead us to make errors in the interpretation of our clinical observations. When a patient improves following treatment it may be due to the treatment itself, but this improvement may also be caused by other factors that have an effect at the same time that treatment is performed (Kamper, 2018(a)). Let’s explore some of those other factors.

Natural History

Often health problems, if they’re not serious conditions, will resolve on their own with just the passing of time, independently of whether someone receives treatment or not (Kamper, 2018(a)). This can lead to us treating someone and seeing them getting better because our intervention coincided with the timing of recovery for that condition through its natural history.

Regression to the mean

It’s common for health problems to fluctuate in how they present and feel. This means that often our patients can feel like they have periods of time where they have very mild or no symptoms at all, with episodes of very severe flare-ups in the middle (Kamper, 2018(a)). People with this type of condition tend to book appointments with a healthcare professional exactly on those episodes when their pain becomes worse. Because of this, the next fluctuation they will experience is that improvement towards more mild symptoms, appearing that they improved after their appointment because of what was done in that appointment (Kamper, 2018(a)).

Placebo Effect

A lot of people have probably heard of this effect by now. It basically describes how when we believe in something, such as that a treatment provided by a healthcare professional will make us better, that expectation will have a physiological response in line with that belief – we will feel better (Kamper, 2018(a)). However, it is important to identify that even though placebo effects are often linked to interventions or treatments, they are not part of the effect of said interventions or treatments (Kamper, 2018(a)).

Polite patients

Most, if not all, healthcare professionals will try to build a positive relationship with people who comes to them for care (Kamper, 2018(a)). It’s easier to try to help someone if they like us and are willing to collaborate. But this can backfire in a way: if our patients really like us, they may want to avoid making us feel bad or useless and will tell us a little white lie of how they are improving a lot, or look and act as if they are much better, even if that is not the case (Kamper, 2018(a)).

On that anxiety and self-doubt-inducing note, I want once again to remind you that none of this means that our personal observations and clinical experience are useless. They are valid sources of knowledge and can help us make decisions about someone’s care. However, we have to recognise and understand how these sources of knowledge can be very faulty and lead us to commit errors.

I hope this text has made you consider keeping open the possibility that what you observe and experience may not be an accurate reflection of reality and that when you are presented with a robust and trustworthy piece of evidence that challenges what you thought was true, even if you don’t accept it straight away, at least consider in your mind: “What if I am wrong here?”.

I can assure you that despite how scary that may sound, a lot more positive than negative will come out of that consideration. It’s normal and healthy to make mistakes and change our minds. It’s not just our observations and thought processes that are flawed. Any piece of information, independently of coming from media, clinical experience, professional courses, colleagues, or even research, can be biased and have flaws (Kamper, 2018(a)). And it’s exactly the bias of that last one that I will be exploring in the next post.

Thank you for reading this far and I will hopefully see you nerds in the next one,

The Physiolosopher.


Bowling, A. Research Methods in Health – Investigating health in health services. 2014, fourth edition. Open University Press. Berkshire, England

Finch, P. M. (2007). The evidence funnel: Highlighting the importance of research literacy in the delivery of evidence informed complementary health care. Journal of Bodywork and Movement Therapies, 11(1), 78–81. https://doi.org/10.1016/j.jbmt.2006.09.001 

Kamper, S. J. (2018 (a)). Engaging with research: Linking evidence with practice. Journal of Orthopaedic and Sports Physical Therapy, 48(6), 512–513. https://doi.org/10.2519/jospt.2018.0701

Kamper, S. J. (2018(b)). Bias: Linking evidence with practice. Journal of Orthopaedic and Sports Physical Therapy, 48(8), 667–668. https://doi.org/10.2519/jospt.2018.0703

Meira, E. (2020). Understanding evidence-based medicine using a funnel analogy. Society for Transparency, Openness and Replication in Kinesiology. https://doi.org/10.31236/osf.io/kr6aq 

Monteiro, S., Sherbino, J., Sibbald, M., & Norman, G. (2020). Critical thinking, biases and dual processing: The enduring myth of generalisable skills. Medical Education, 54(1), 66–73. https://doi.org/10.1111/medu.13872 

Phua, D. H., Fams, E., & Tan, N. C. (2013). Cognitive Aspect of Diagnostic Errors (Vol. 42, Issue 1). 

Richardson, L. G. (2014). Awareness of Heuristics in Clinical Decision Making. Clinical Scholars Review, 7(1), 16–23. https://doi.org/10.1891/1939-2095.7.1.16 

Sacket, D. L., Rosenberd, W. M., Gray, J. A. M., Haynes, R. B., & Richardson, W. S. (1996). Evidence based medicine: what it is and what it isn’t. BMJ, 312, 71–72. Saposnik, G., Redelmeier, D., Ruff, C. C., & Tobler, P. N. (2016). Cognitive biases associated with medical decisions: a systematic review. BMC Medical Informatics and Decision Making, 16(1), 1–14. https://doi.org/10.1186/s12911-016-0377-1

The Pre-Socratics part 7 – The Sophists

In this next text through the history of philosophy we will be looking at a controversial, but influential group. Most of the information we have about this group comes to us from the writings of Plato, who didn’t like them very much (Kenny, 2010). So this biased view is something we have to keep in mind when reading and learning about them.

This group was known as the Sophists. They were a group of well-educated men who made their living by travelling through different cities offering education on several subjects including philosophy, rhetoric, mathematics, history, geography (Kenny, 2010; Russel, 1946). However, their main focus of study was in debating and arguing (Kenny, 2010; Russel, 1946).

They were mainly active around 5th century, a time during which Democracy and democratic institutions where at the core of most things in Athenian society (Adamson, 2014; Kenny, 2010; Russel, 1946). Thus, to either obtain political power and rise in this world, or plead for yourself in court, your main tool was persuasion (Adamson, 2014; Kenny, 2010; Russel, 1946). In either situation, you would have to use words to persuade the present assembly into taking or side or turning them against your opponents (Adamson, 2014; Kenny, 2010; Russel, 1946) This lead to most of the Sophist’s clients to be young men either trying to get into a political career or to make a case in court (Adamson, 2014; Kenny, 2010; Russel, 1946). Initially, the word ‘Sophist’, meant something similar to what we mean by a ‘professor’ in present day (Russel, 1946). However, possibly with some influence of Plato, this name started having a different meaning. Presently, ‘sophistry’ (what is practiced by a ‘sophist’) is understood as meaning using argumentative tricks, such as using misleading words in sentences that sound true, but without any facts to back them up, to persuade people (Adamson, 2014; Kenny, 2010) So if you call someone a Sophist, you’re saying they use deceptive arguments on purpose to persuade people of something, independently of there being any truth behind what you’re saying (Adamson, 2014; Kenny, 2010) – basically a present-day politician.

A day to day application of Sophist relativism

Several sophists where well known throughout history, but if you had to chose one name to represent them, that would have to be Protagoras (Adamson, 2014; Kenny, 2010; Russel, 1946)

One, if not the most famous of Protagoras sayings is “Man is the measure of all things, both of things that are that they are, and of things that are not that they are not” (Adamson, 2014; Kenny, 2010; Russel, 1946). This is one of the first clear instances of a relativist epistemology (Adamson, 2014; Kenny, 2010; Russel, 1946)

Protagoras firmly believed that what is true to a particular person is true for that person. The natural conclusion to this is that everyone’s beliefs are truth, but the only form of truth that exists is a relative one (Kenny, 2010). Because of this view, Protagoras was said to have been someone who could argue equally for both sides of any question (Kenny, 2010), because he didn’t see any of the arguments being truer or better in an absolute manner, they could only be truer or better than the other in a way relative to each person (Adamson, 2014). This view that an independent, objective truth does not exist fits withing the philosophical school of scepticism, leading to the Sophists also being seen as sceptics (Kenny, 2010; Russel, 1946). A sceptic is anyone who views the truth as something very, very difficult, even impossible, to discover (Kenny, 2010). As an universal, objective idea of truth does not exist, its replacement with a relative form of truth is considered by some a form of scepticism in itself (Kenny, 2010).

Another well-know Sophist, with similar sceptical views was Gorgias, who in his work “On What is Not”, argued three conclusions (Kenny, 2010):

  1. That there is nothing.
  2. That if there is anything, it cannot be known.
  3. That if anything can be known, it cannot be communicated by one person to another.

He reached these conclusions mainly through complex plays on semantics and wording, and all have been answered throughout history by different philosophers, the first by Socrates (as told by Plato), the second by Aristotle and the third on in the XX century by Wittgenstein (Kenny, 2010). I will cover these in other texts about the respective philosophers, the first two soon, and hopefully my sense of duty will keep me going until the last. This highlights an important role that the Sophists had, despite their fancy, misleading word-play and extreme view that as there is no absolute truth, persuasion is all we have (Adamson, 2014). It was through their role as argumentative adversaries that other philosophers where pushed to reflect on the nature of reality and truth, develop and polish some of the many influential ideas they have been accredited with throughout history.

I think this beautifully illustrates the importance of dialogue with people who share viewpoints that are different or opposite to ours. Ideas can be improved through the synthesis of a thesis and its antithesis.

Illustration of the indirect role of Sophists on the great ideas of history

If we reflect on the notion of truth, science has demonstrated certain facts about our reality, such as gravity, we know that there is certain knowledge we are still very far from attaining and we can question if we ever will. After all, we humans have limitations in our ability to understand the world and are less rational than we would like to admit.

Making parallelism to my clinical practice, we have evidence that informs on fundamental rules such as anatomy and physiology, which factors have an impact on someone’s presentation and recovery, with some of these aspects being quantifiable in an objective way. However, even in the quantifiable variables, we often work within statistical intervals, and we always must adapt the evidence to the individual in front of us: a relative application of systematically ascertained facts.

On the other hand, in no way is this a justification that all options you pick have the same value behind them and that you can just do whatever you want. One thing is being aware of a degree of relativism, another whole thing is having an uncritical approach to clinical practice. This will be answered by the same argument that Democritus presented to Protagoras: this view is self-refuting because if all beliefs are true, then the belief that not every belief is true will itself also be true (Kenny, 2010).

But what do you think? Is there an absolute truth we should strive for?

Or do you think that only our subjective perception of things will matter as long as it sounds right?

If it helped you live your life in a better or more comfortable way, would you accept and defend a belief independently of the truth behind it?

I hope to see you amazing nerds in the next text,

The Physiolosopher.


Adamson, P. 2014. Classical Philosophy: A history of philosophy without any gaps, Volume 1. 1st edition. Oxford University Press: Oxford.

Kenny, A. 2010. A New History of Western Philosophy: In Four Parts. Reprint Edition. Oxford University Press: Oxford.

Russel, B. 1946. History of Western Philosophy. Routledge – Taylor and Francis Group: New York.

Dealing with Humans, Dealing with Complexity

The assumption that training principles applied to pain and associated disability is yet another sign of our deep craving for defined, guiding reasoning structures – from A we progress to B, from D we regress to C etc…

It reflects our inner aversion to complexity, to subjectivity. But in reality, we are all these complex and naturally subjective beings.

You deal with humans? You deal with complexity. You deal with subjectivity. Listen and learn to make sense of them. Which is so, so much.

You have Science to keep you in touch with earthly reality. Use the best scientific evidence as a guide. And also, to define your lines. It will light the way! (Don’t you know what makes “the best available scientific evidence”? You may not have realized it, but you made a commitment to it the day you became a healthcare professional. Invest in it, you won’t regret it!)

Mix it up there and see how the whole is so much more than the sum of its parts. There you have your recipe. Reason, reflect and adjust if necessary. In one way or another. Yes, it is not straightforward. Sometimes it is also sideways and backwards. Deal with it.

 Sometimes you will “fail”. Deal with that too. If the therapeutic relationship is “right” it will not be the end of the world and you both will certainly find a new path. Which may well not be with you. Yes, you have to deal with that too. And that’s really OK.

Complexity, let it be.


The myth of “Text Neck”

The content of this post was originally going to be included in the text on myths surrounding back pain (link to post), however because it is a somewhat complex topic and it will take some explanation to get my point across, it ended up developing into a topic worthy of its own text.

This time I’m looking at the myth of what is called ‘Text Neck’. Our necks are another part of our spine about which we have been given a lot of warnings. All over the internet there has been the clamouring for the recognition of this supposed condition, called “text-neck”. Just google it yourself – there are over 4 billion search results like it’s a very well-established thing.

Basically, like with the rest of our spine, we are told that flexing our neck, even though flexion is a natural movement of all parts of our spine, will cause either pain, injuries, or other health problems. So, the question here is: what is the actual relationship between a flexed neck, a forward head posture in clinical terminology, and pain in our neck?

One of the biggest and most recent studies about this is a systematic review and meta-analysis by Mahmoud et al (2019). They found 15 studies appropriate for review comparing measures of head and neck posture in people with and without neck pain. Most studies were of weak or moderate methodological quality (quality with which they are designed and executed) and there were a lot of differences between how head and neck posture was measured, which can make comparisons difficult and limits how sure we can be about the conclusions (Mahmoud et al, 2019). The authors found that there is an increase in forward head posture in adults with neck pain compared to adults without pain. However, there was no relevant difference between forward head posture in adolescents and adults over 50 years of age with or without neck pain.

So what gives? As a teenager, the age when we’re told that we’re always looking down at our phones, it doesn’t matter how you hold your neck, out of a sudden when you reach adulthood your neck posture starts giving you pain but that stops when you reach 50? I don’t know about you, but if the position is the problem, then this doesn’t make sense to me. Maybe your neck posture itself is not that relevant for having pain in your neck.

Considering that other studies looking at neck posture in adolescents do not show a relationship between static head posture, your posture when you’re not moving, and neck pain the authors hypothesize that this happens due to teenagers still being able to move their necks out of that flexed position and that what causes pain in adults is the loss of that ability (Mahmoud et al, 2019). The authors also theorize that the onset of pain as adults is related to loss of neck muscle endurance and flexibility as we age (Mahmoud et al, 2019).

There is still something here that doesn’t make sense. If we do assume that neck pain is caused by loss of range of movement of our neck, and this loss comes with age, why do we again stop seeing a link between neck posture and pain in those over 50 years of age?

I hope you’re starting to see how the research around this topic is not as straightforward as some people on the internet want us to believe.

But there is also another detail that limits being able to say a certain posture causes neck pain. All the studies included by the authors in the review are cross-sectional (Mahmoud et al, 2019). This means they measure and analyse people at a single point in time and do not follow them up more over time. Because of this, this study design can’t find a relationship of causality. Who can assure us the reason they appeared with a flexed neck at that point in time wasn’t because they were in pain? Or that because they were being observed, that didn’t cause them to change how they hold their body to try to meet what they thought was the expectation of the examiners? We don’t know which one came first and this highlights the very important difference between correlation and causation.

Just because things correlate, it doesn’t mean they cause each other. Otherwise, we need to stop Nicolas Cage from doing any more films.

Maybe it’s not about your posture. The association between neck pain and the amount of time we use our phones has also been looked at by Blumenberg et al (2021) and they did find that people who spent between 3 hours or more per day using their mobiles showed an increase prevalence of neck pain, as well as pain on other parts of the back. It’s important to note that they did not measure posture at rest, while using phones, or during activities.

So maybe it’s about making sure you get your joints to move often to keep them able to do so and keeping your muscles strong so they can actually move your joints. Maybe it’s about reducing the amount of time you spend in any one given posture, be it upright or flexed, sitting or standing.

How do you do that? You do it by reducing sedentary time and increasing your general amount of physical activity. Another thing to add to the benefits of exercise

But we meet the same problem again. Even though this study by Blumenberg et al (2021) used subjects from a study called the 1993 Pelotas birth cohort, which followed people from birth to when they were 22 years old, the authors only measured neck pain and total hours of use of mobile phones on the 22 years follow-up – this is, in a single point of pain. Thus, as identified by the authors, this data can only be considered cross-sectional (Blumenberg et al, 2021). To properly understand a causal relationship, we have to actually follow up people over multiple points in time and monitor the present, or lack thereof, of certain factors and their expected consequences. This is called a longitudinal design study. Luckily for us, there are a few recent studies looking exactly into that.

First, we have a study by Gustafsson et al (2017) focused on the topic of neck pain and mobile phone use. They started by examining 7092 people and the number of daily text massages. The authors managed to follow up with 4148 of those after 1 year, and again at 5 years with 2724 people from the original group (Gustafsson et al, 2017). They found that people who already had neck pain on initial assessment and were in the group with the highest reported number of daily texts, continued to have neck pain at 1-year follow-up, however, this association disappeared at 5 years (Gustafsson et al, 2017). In people without neck pain to start with, there was no correlation between developing neck pain at 1 or 5 years with any frequency of daily text messages (Gustafsson et al, 2017). One obvious limitation of this study is that they didn’t measure neck or head posture.

More recently we have the study produced by Richards et al (2021) which used the group of 2868 participants originally followed by the Raine Study who were enrolled in 1989, at around their 18th week of gestation – yes while still in the womb – and the followed-up in regular intervals. The good thing about this study is that they actually assessed neck posture, as well as neck pain, and at two different points in time: when participants were 17 years old and again at 22 years old. Let’s quickly go through their findings. Having neck pain at 17 was associated with having neck pain at 22, independently of other factors. So if you have neck pain when you are younger, you are more likely to still have it when you are older.  But now comes the interesting part. In male participants, there did not appear to be any particular factors that strongly correlated to having or not having neck pain, but there was one such factor in females: compared with having an upright posture, having a slumped or flexed posture appears to decrease the risk of having neck pain when participants became 22 years old. So, if you’re female, having a more rounded, head forward posture will reduce your chances of having neck pain at 22 years of age, but not if you’re a male? How do we make sense of this information?

Well, maybe it indicates that your posture is not a significant factor in the development, or not, of neck pain. I hope I have been able to demonstrate that across the biggest and best-designed studies, like with back pain (link to post), we cannot find a causal relationship between our neck and head posture, nor the amount of texting we do on our phones and the risk of developing neck pain. We see that people can present with flexed postures, however, we can’t say that isn’t a consequence of pain instead of the other way around. And in some cases, a flexed posture even seems to lead to less pain.

Am I safe to say R.I.P to the myth of ‘text neck’ and ask that we please stop making up new diagnoses or diseases without sufficient data to back them up? As soon as another non-evidence-based belief is made up, it easily gets widely spread by all forms of media around us (Slater et al., 2019), contributing to people believing it is a thing when it isn’t. Misinformation is really easy to spread, particularly in a society where critical thinking often isn’t promoted or rewarded.

Don’t be afraid to flex your spine, it is made to move. And don’t be afraid to read or be on your phone, at least not due to fear of it damaging your neck. Your body is more resilient than that. But don’t forget to also be active and get some exercise in. That’s how you ensure your joints remain healthy and able to move, amongst many other benefits.

Thank you for reading through and as always, if you learned something and/or found this text interesting, please share it all over social media so you can help others learn. See you in the next one.


Blumenberg, C., Wehrmeister, F. C., Barros, F. C., Flesch, B. D., Guimarães, F., Valério, I., Ferreira, L. Z., Echeverria, M., Karam, S. A., Gonçalves, H., & Menezes, A. M. B. (2021). Association of the length of time using computers and mobile devices with low back, neck and mid-back pains: findings from a birth cohort. Public Health, 195, 1–6. https://doi.org/10.1016/j.puhe.2021.04.003

Christe, G., Nzamba, J., Desarzens, L., Leuba, A., Darlow, B. and Pichonnaz, C. 2021. Physiotherapists’ attitudes and beliefs about low back pain influence their clinical decisions and advice, Musculoskeletal Science and Practice. Elsevier Ltd, 53(April), p. 102382. doi: 10.1016/j.msksp.2021.102382.

Christe, G., Pizzolato, V., Meyer, M., Nzamba, J. and Pichonnaz, C. 2021. Unhelpful beliefs and attitudes about low back pain in the general population: A cross-sectional survey. Musculoskeletal Science and Practice. Elsevier Ltd, 52(August 2020), p. 102342. doi: 10.1016/j.msksp.2021.102342.

Foster, N. E., Anema, J. R., Cherkin, D., Chou, R., Cohen, S. P., Gross, D. P., Ferreira, P. H., Fritz, J. M., Koes, B. W., Peul, W., Turner, J. A., Maher, C. G. (2018). Prevention and treatment of low back pain: evidence, challenges, and promising directions. In The Lancet (Vol. 391, Issue 10137, pp. 2368–2383). Lancet Publishing Group. https://doi.org/10.1016/S0140-6736(18)30489-6

Gustafsson, E., Thomée, S., Grimby-Ekman, A., & Hagberg, M. (2017). Texting on mobile phones and musculoskeletal disorders in young adults: A five-year cohort study. Applied Ergonomics, 58, 208–214. https://doi.org/10.1016/j.apergo.2016.06.012

Korakakis, V., O’Sullivan, K., O’Sullivan, P. B., Evagelinou, V., Sotiralis, Y., Sideris, A., Sakellariou, K., Karanasios, S., & Giakas, G. (2019). Physiotherapist perceptions of optimal sitting and standing posture. Musculoskeletal Science and Practice, 39, 24–31. https://doi.org/10.1016/j.msksp.2018.11.004

Laird, R. A., Kent, P., & Keating, J. L. (2012). Modifying patterns of movement in people with low back pain -does it help? A systematic review. In BMC Musculoskeletal Disorders (Vol. 13). BioMed Central Ltd. https://doi.org/10.1186/1471-2474-13-169

Lima, M., Ferreira, A. S., Reis, F. J. J., Paes, V., & Meziat-Filho, N. (2018). Chronic low back pain and back muscle activity during functional tasks. Gait and Posture, 61, 250–256. https://doi.org/10.1016/j.gaitpost.2018.01.021

Mahmoud, N. F., Hassan, K. A., Abdelmajeed, S. F., Moustafa, I. M., & Silva, A. G. (2019). The Relationship Between Forward Head Posture and Neck Pain: a Systematic Review and Meta-Analysis. In Current Reviews in Musculoskeletal Medicine (Vol. 12, Issue 4, pp. 562–577). Springer. https://doi.org/10.1007/s12178-019-09594-y

Richards, K. v., Beales, D. J., Smith, A. L., O’sullivan, P. B., & Straker, L. M. (2021). Is neck posture subgroup in late adolescence a risk factor for persistent neck pain in young adults? a prospective study. Physical Therapy, 101(3). https://doi.org/10.1093/ptj/pzab007

Sheha, E. D., Steinhaus, M. E., Kim, H. J., Cunningham, M. E., Fragomen, A. T., & Rozbruch, S. R. (2018). Leg-Length Discrepancy, Functional Scoliosis, and Low Back Pain. In JBJS reviews (Vol. 6, Issue 8, p. e6). NLM (Medline). https://doi.org/10.2106/JBJS.RVW.17.00148

Slater, D., Korakakis, V., O’Sullivan, P., Nolan, D., & O’Sullivan, K. (2019). “Sit up straight”: Time to Re-evaluate. In Journal of Orthopaedic and Sports Physical Therapy (Vol. 49, Issue 8, pp. 562–564). Movement Science Media. https://doi.org/10.2519/jospt.2019.0610

The Pre-Socratics part 6 – Caring about Health

Welcome to another text where we continue our journey through the philosophers who developed the ideas that inspired most of our own at present. Today we are going to explore a name that may not be as obscure as the ones before: Hippocrates.

Giving some justification to my personal interest in philosophy, in ancient Greece, philosophy and medicine were tightly bound, as it happened with many other fields of present-day science, both having an influence on each other (Adamson, 2014). Hippocrates is originally from an island of the coast of Ionia (where the Milesian school was) name Kos. We don’t have full certainty, but the available evidence suggests that Hippocrates is younger than Socrates and a likely contemporary of Plato and possibly Aristotle, placing him between late 4th century BC and early 3rd century BC with Hippocrates’ works being influential to them (Adamson, 2014).

Hippocrates is famously hailed as the father of medicine (Adamson, 2014; Kleisiaris et al., 2014) for both his great achievements in ancient Greek medicine as well as being credited with developing a lot of the ideas that still function as the philosophical core of modern medicine. One of his most famous, and still influential to present day, ideas is what is considered the fundamental precept of medical ethics: “Primum non nocere”, “First of all, do no harm” (Adamson, 2014). This idea first originated in one of Hippocrates’ texts, the Epidemics, which interestingly analysed the disease outbreaks at the time (Adamson, 2014). This text is one of many that composes a whole body of texts commonly known as the Hippocratic Corpus. These texts would cover a range of topics ranging from different diseases, drugs and medical ethics even (Adamson, 2014).

Within its records we find that when the Greeks first started organising the Olympic Games, some people started specialising in the care of athlete’s health and the prevention of injuries, under the title of “paidotrivai”(Kleisiaris et al., 2014), being the first to use massage oils, specifically olive oil, with the aim of warming up athletes and avoid sport injuries (Kleisiaris et al., 2014). I consider the fact that a lot of this practices still prevail not as a sign of the genius of Hippocratic medicine, but of how outdated some of present-day practices are. In the Hippocratic corpus we also find the first descriptions of treatment of traumatic wounds, fractures and surgeries such as amputation to stop gangrene, which were used until at least the Middle Ages (Kleisiaris et al., 2014).

Despite bearing his name, not all these texts were written by Hippocrates, but also by other physicians who learned from him or followed in his teachings (Adamson, 2014). There were forms of archaic medicine before this, but the Hippocratic corpus is where we found the earliest surviving systematic texts on medicine (Adamson, 2014). Another common trend between medicine and philosophy at the time was the separation from religious practices and beliefs, instead seeking to have a basis on rationality and science (Adamson, 2014; Kleisiaris et al., 2014). Thus, the underlying philosophy of Hippocratic medicine is that medicine should be seen as a scientific discipline that bases itself on the natural sciences when diagnosing, preventing and treating diseases (Kleisiaris et al., 2014). However, this separation was not complete. While the overall belief at the time was that diseases were caused by the gods, in the Hippocratic corpus it is stated if diseases were in any way sacred, was because they were caused by forces of nature that were themselves sacred, such as the sun or wind (Adamson, 2014). The idea that gods would just randomly curse individual mortals was argued against, but there was still room for belief in gods and the divine (Adamson, 2014).

Still, Hippocrates contributed to the first steps of modern medicine, arguing that diagnosis, prognosis and treatment should be based on detailed observation, reason and the accumulation of observed experience (Kleisiaris et al., 2014). In other words, medicine should be based on knowledge obtained from the available empirical evidence (Kleisiaris et al., 2014).

However, the bigger influence to Hippocratic medicine came from the philosophical and scientific theories of the pre-socratics, such as Empedocle’s theory of the four elements that I covered previously. You should read the previous text for further details on Empedocle’s theory, but put simply, everything in the universe is made of four elements: air, earth, fire and water (Adamson, 2014). This will thus include human bodies, leading to our link between this theory and medicine. If we got ill, it was because the elements in our body are not in the proportion they should (Adamson, 2014; Kleisiaris et al., 2014). Also utilising the same theory of balancing the four elements and how hot, cold, dry or wet our body to explain how they worked, Hippocratic doctors would already utilise certain drugs as part of their treatment (Adamson, 2014).

This type of theory may seem non-sensical to us, but it’s not that far-fetched when you consider the observations that could be made at the time such as being quite common to develop a fever when you’re ill or that when people die they stop breathing (Adamson, 2014). Still, it was insisted by the Hippocratic doctors that the practice of medicine isn’t as simple as memorizing a few theoretical principles and applying these automatically, being more akin to a form of art (Adamson, 2014). I personally don’t like this phrasing without proper contextualisation, as it opens the door for a lot of esoteric quackery to be accepted into medicine and healthcare. What is meant by art here is a non-rigid, holistic approach to medicine, one where we treat the whole body, not just the symptomatic body part, and we consider the individual circumstances of each patient (Adamson, 2014). Still relating to this theory and within the writings found in the Hippocratic corpus, was the first mention of the four-humour theory (Adamson, 2014; Kleisiaris et al., 2014). According to this theory, for us to be and remain healthy, there has again to be balanced proportions within our body, not of the elements, but of certain types of fluids called the bodily humours: blood, phlegm, yellow bile, and black bile (Adamson, 2014). Based on this, Hippocratic doctors had also started using bloodletting and cupping (Adamson, 2014). They would, however, advise against using this often and displayed an overall reluctant stance against any type of “invasive” procedures (Adamson, 2014). Interestingly, even though I like to think no one with a minimal level of knowledge of biology and ability to think critically nowadays would take the four-humour seriously, a lot of these interventions are still greatly used and advertised presently even amongst healthcare providers. This is not due to shown effectiveness in quality critical trials, so I do wonder what makes people still commonly utilise outdated practices such as cupping if the theory explaining its acting mechanism is not supported by biology? Why have certain sectors and agents of healthcare failed to move from 400BC? I’ll explore this more below when I highlight what I consider to a very pertinent text from the Hippocratic corpus. But first I want to discuss what was actually the principal and most common of the treatments prescribed by Hippocratic doctors: the right diet and amount of exercise (Adamson, 2014; Kleisiaris et al., 2014).

In general, Hippocratic doctors were firm supporters of preventative medicine, (Adamson, 2014) and argued the importance of environmental causes and natural treatments of diseases, the importance of psychological factors, nutrition and lifestyle, independence of mind, body and spirit, and the need for the harmony between the individual and the social and natural environment as both causes and treatment of health problems (Kleisiaris et al., 2014). Ancient Greeks in general believed that mental and physical health were connected, with the phrase “healthy mind in a healthy body” came from this belief (Kleisiaris et al., 2014). In this sense, it appears they were ahead of us in their understanding of health, as amongst the general public and health care practitioners, the importance of psychosocial factors remains underrecognized (Haslam et al., 2018). This shows a view that aimed to treat the individual as whole, addressing the psychosomatic entity that is a disease, instead of treating symptoms (Kleisiaris et al., 2014). In line with this, the assessment performed by Hippocratic doctors included noting geographical location, climate, age, gender, habits, diet, rational moods swings, duration of sleep, appetite, thirst, nausea, location and severity of pain, chills, coughing, sneezing, and menstrual changes (Kleisiaris et al., 2014). A lot of these details remain part of modern medical history taking. Based on this information and examination of symptoms, Hippocratic doctors would diagnose patients and treat them, establishing the basis of medicine for the present day (Kleisiaris et al., 2014). Not only this, but the Hippocratic corpus also introduced many of the medical terms still used today such as symptom, diagnosis, therapy, trauma, sepsis, diabetes, arthritis, cancer, coma, paralysis, epilepsy, among others (Kleisiaris et al., 2014).

One particular text in the corpus I want to highlight is the famous Oath (Adamson, 2014) which focuses on professional integrity, benevolence and human dignity (Kleisiaris et al., 2014) In particular, I want to highlight some of the points from the Modern version of the Hippocratic Oath, that were already present in Hippocrates’ arguments: (Harris and Buchbinder, 2021):

  • Medicine should be based on and respect the evidence produced through the scientific method.
  • Overtreatment and overdiagnosis should be avoided.
  • Understanding of natural history of symptoms and reassurance of patients takes precedence over medical interventions.
  • Doctors should be honest about the actual limited effectiveness of certain medical interventions.
  • Treatment should be based on individual patient circumstances and presentation as opposed to scans and other investigations.
  • The focus on medicine should be on public health measures focused on healthy lifestyle as opposed to more passive and sometimes invasive interventions.

I find it astonishing that despite these values being present since Hippocrates and doctors the oath being considered the code of conduct for medical doctors even in present day, a lot of the current problems in healthcare stem from these ideals not being adhered to. Some examples are unnecessary imaging, opioids, and surgery for non-serious back pain; arthroscopic surgery for knee osteoarthritis; subacromial decompression surgery for shoulder pain; platelet-rich plasma injections for tendinopathies and osteoarthritis. (Harris and Buchbinder, 2021). I will also point the finger at my own profession of physiotherapy and highlight other problematic examples such as offering “diagnoses” that are no more than natural anatomical variations, also overestimating the effectiveness of interventions such as massaging, manipulating and sticking needles in people’s bodies, disregard for patients’s individual environment and circumstances. Why do healthcare professionals behave in this way? Curiously because of the following trait that they appear to have in common with many practitioners of alternative “medicines”: reluctance to admit that they don’t know and seeing not testing or treating a patient as a failure to care (Harris and Buchbinder, 2021).

This, however, is not entirely their fault. Just like patients are part of an environment that has an effect in their health, so do healthcare professionals work in a system that propagates the expectation from both clinicians and patients that there is always a need to exclude or provide a diagnosis or a treatment, where diagnoses and diseases are created to treat measured values or other findings independently of how these correlate to symptoms, and treatments “need” to be tried instead of choosing advice, reassurance and simply waiting while monitoring (Harris and Buchbinder, 2021).

This is way I think we need to again create a better link between philosophy and healthcare. I’ll go even as far as arguing that we need to bring back philosophy into most aspects of our quotidian. We have so much to learn from exploring how ideas came to be over the ages. I hope this journey through the philosophers of history has started to make you aware of this. I will continue this journey at another time. Thank you for reading through and as always, if you learned something and/or found this text interesting, please share it all over social media so you can help others learn. See you in the next one.


Adamson, P. 2014. Classical Philosophy: A history of philosophy without any gaps, Volume 1. 1st edition. Oxford University Press: Oxford.

Harris, I. A., & Buchbinder, R. (2021). How doctors are betraying the Hippocratic oath. The BMJ, 375. https://doi.org/10.1136/bmj.n2807

Haslam, S. A., McMahon, C., Cruwys, T., Haslam, C., Jetten, J., & Steffens, N. K. (2018). Social cure, what social cure? The propensity to underestimate the importance of social factors for health. Social Science and Medicine, 198, 14–21. https://doi.org/10.1016/j.socscimed.2017.12.020

Kleisiaris, C. F., Sfakianakis, C., & Papathanasiou, I. v. (2014). Health care practices in ancient Greece: The Hippocratic ideal. In J Med Ethics Hist Med (Vol. 7).

Introduction to Evidence-Based Practice part 2: Framework for Understanding

This text is the second part of my attempt at introducing you to evidence-based practice and making this process generally better understood by everyone. If you haven’t already, check part 1 before reading this one to understand why we can’t just rely on our own thought processes to gather knowledge about the world and make decisions in healthcare. Our minds, even in their most rational moments, are flawed things – and this statement is devoid of any moral judgment. It’s just how we are, myself included. 

Throughout the centuries, a lot of smart people have been thinking about this problem of overcoming the limitations of our cognitive process and better understand both the world and ourselves, as well as help us decide on the best way of doing things. Let’s have a look at what has been done. 

Evidence-based medicine is not something just for academics or scholars, as from the beginning it was created with the aim of educating front-line clinicians (Djulbegovic and Guyatt, 2017). This is reinforced by the notion that one of the characteristics that define a group of people as a profession is the opportunity to develop knowledge through research activity that will then be utilised to inform said practice (Finch, 2007). 

Part of the reason why Evidence-based medicine was created was the recognition, which it itself does, that understanding research, its results, and applying it to individuals who often don’t share the same characteristics as those selected for studies is quite difficult (Djulbegovic and Guyatt, 2017). The best way of talking about a difficult topic is to start by defining what we are actually talking about. In part 1 I presented the initial definition of Evidence-based medicine proposed by Guyatt et al (1992), which I recognise may point us towards what not to do more than what we should be doing in order to have an evidence-based practice. But worry not, as its definition has been clarified over time and since 1996 is described as integrating the best available research evidence, the individual clinician’s experience and expertise, as well as the patient’s values, preferences and circumstances (Sacket et al, 1996; Finch, 2007; Meira, 2020).

But let’s not stop here, let’s define what is meant by each of these three elements. The best available research evidence means looking at all available evidence relating to our clinical question in a systematic manner (Meira, 2020). This sounds very laborious, but the reason it needs to be done is that not all pieces of evidence obtained from research have the same quality and presently it is very easy to find a research article that supports or favours our preferences (Djulbegovic and Guyatt, 2017; Meira, 2020). It is also arguable that the higher the quality of the evidence, the closer to the truth are our conclusions regarding diagnostics, prognosis, and effects of interventions (Djulbegovic and Guyatt, 2017). Thus, we come to the first epistemological principle of Evidence-based medicine: not all evidence is created equal and clinical practice should be based on the best available evidence (Djulbegovic and Guyatt, 2017). 

Previously, this was associated with the methodological design of the study, with randomised controlled trials being considered the best studies and everything else, was considered to be below that type of design. But science and research aren’t perfect, as many critics are ready to point out. However, this is not in itself an argument to discredit the use of the scientific method or evidence-based practice. Interestingly, these critics forget to mention that these flaws have been identified by the same researchers who partake in the scientific method (Finch, 2007; Djulbegovic and Guyatt, 2017). 

At present, a study’s quality is considered based on how well the study design fits the question being asked and how well it fits the particular clinical setting and patient circumstances, as well as the quality, not category, of the methodological design of said study (Finch, 2007; Djulbegovic and Guyatt, 2017). In order to help critically and systematically assess the quality of a research paper, several tools have been developed such as the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system published in 2004 (Oxman, 2004), the Preferred Reporting Items for Systematic reviews and Meta-Analyses (Liberati et al, 2009) and the PROSPERO international prospective register of systematic reviews (Booth et al, 2012). 

Next, clinical expertise refers to being skilled in critical thinking. Clinical expertise is more complex than supporting a claim by saying “in my professional experience”. It is a nuanced process that requires a synthesis of possible contradictions during moments of uncertainty, instead of just saying something is ‘right’ or ‘wrong’ (Meira, 2020). Even though scientific literature cannot deny what we see in clinic, it can however refute our explanations of those events. In other words, even if something appears to work during practice, after being scrutinized through current evidence, we may find that neither our explanation or the perceived benefit of the treatment approach are accurate (Meira, 2020). This is exactly why science doesn’t work by results of individual studies or observations but from the knowledge obtained from critically analyzing the totality of existing research on a topic (Djulbegovic and Guyatt, 2017). Following this thought process, we have arrived at the second epistemological principle of Evidence-based medicine: the quest for truth is best accomplished by analyzing the totality of the evidence, instead of just selecting evidence that favours a particular argument (Djulbegovic and Guyatt, 2017). 

Lastly, but still highly important, we have patients’ preferences and circumstances. The patient is always the final decision maker (Meira, 2020). I’m going to confess this is a view I have not always shared. Throughout my training I was taught the idea that clinicians are the experts with all the knowledge, so during the beginning of my career, I often would consider that a patient’s opinion was not worth evaluating when deciding on care. Patients don’t have any clinical knowledge, how could their opinion be useful in healthcare? I’m sharing this to show that I’m not above making mistakes and continue to make an effort to learn more and improve – this website and these texts are part of that effort. 

We need to consider the patient’s circumstances and preferences because the first may be a barrier to the direct application of research findings, as the patient’s presentation may not match the sample used in clinical studies, and neither we nor the patient may have the same equipment or time resources as the ones used in the literature (Djulbegovic and Guyatt, 2017; Meira, 2020); the latter also needs consideration as patients will be the ones living with the consequences, positive or negative, of their decision (Djulbegovic and Guyatt, 2017; Meira, 2020) and sometimes the evidence is still not fully clear in what interventions are more beneficial, not giving us a clear path to follow, so we may follow what the patient thinks will be more suitable for them and increase both adherence and develop the therapeutic relationship. This can be neatly summarised into the third epistemological principle of Evidence-based medicine: we need to consider patients’ values and preferences during clinical decision-making. Evidence is necessary, but not sufficient for effective decision making, which has to consider the relevant consequences to the patient within their context and circumstances (Djulbegovic and Guyatt, 2017). 

We cannot say we are evidence-based clinicians if we don’t follow these principles and integrate these elements into our daily practice. However, it is important to point out that although the best available evidence, clinical expertise, and patient circumstances and preferences are all necessary for evidence-based practice, they don’t all have necessarily the same weight in informing clinical decisions. In the past some authors and clinicians have described these three elements as “three legs of a stool”, which has led to mistakes such a citation that supports our bias being confused for available evidence, choosing an intervention that suits our bias being for clinical expertise and the patient agreeing to that intervention that we prefer and is supported by a single article being confused for integrated patient’s values into decision making (Meira, 2020). 

Instead, Evidence-based medicine is better seen as a funnel, a framework that guides our practice by narrowing the highest quality evidence, which is then through clinical expertise further narrowed and explained to the patient, who then based on their preferences and circumstances will further narrow down the available options into a plan that suits them. This framework has been described and illustrated by Meira (2020) in an excellent way: 

Also worth notice, is that the steps of this framework can only be taken in the narrowing direction. In other words, it is not evidence-based to select an intervention because it fits the clinician or patient preference if it is not supported by the totality of the best quality evidence. By practicing in this way, we risk selecting interventions that have not shown to be effective, wasting both the patient’s time and money, as well as possibly endangering the safety and well-being of the patient. 

Considering this, it is arguable that developing our research literacy is as important as developing any other knowledge or skill related to patient assessment (Finch, 2007). Thus, universities should prioritize that a significant focus of their curricula is guiding students towards competence in understanding research methodology, being able to perform critical evaluation of evidence, and systematically applying it to their clinical setting (Finch, 2007). 

This text is in no way an exhaustive description or explanation of what is Evidence-based medicine and how it is informed by the scientific process. However, I hope it has helped you understand that Evidence-based medicine is not a dogmatic faith-like cult, but instead a critical and systematic process that aims at challenging our own bias through a pursuit of a humanely achievable approximation of the truth that promotes patient safety and better healthcare outcomes. 

Don’t forget to share if you found this text interesting and comment if you disagree or have questions about any part of it. Hopefully, I’ll see you in the next text. 


Booth, A., Clarke, M., Dooley, G., Ghersi, D., Moher, D., Petticrew, M., & Stewart, L. (2012). The nuts and bolts of PROSPERO: An international prospective register of systematic reviews. Systematic Reviews, 1(1). https://doi.org/10.1186/2046-4053-1-2 

Djulbegovic, B., & Guyatt, G. H. (2017). Progress in evidence-based medicine: a quarter century on. In The Lancet (Vol. 390, Issue 10092, pp. 415–423). Lancet Publishing Group. https://doi.org/10.1016/S0140-6736(16)31592-6 

Finch, P. M. (2007). The evidence funnel: Highlighting the importance of research literacy in the delivery of evidence informed complementary health care. Journal of Bodywork and Movement Therapies, 11(1), 78–81. https://doi.org/10.1016/j.jbmt.2006.09.001 

Guyatt, G., Cairns, J., Churchill, D., Cook, D., Haynes, B., Hirsh, J., Irvine, J., Levine, M., Levine, M., Nishikawa, J., Sackett, D., Brill-Edwards, P., Gerstein, H., GIbson, J., Jaeschke, R., Kerigan, A., Nevile, A., Panju, A., Detsky, A., … Tugwell, P. (1992). Evidence-Based Medicine – A New Approach to Teaching the Practice of Medicine. JAMA, 268(17), 2420–2425. 

Liberati, A., Altman, D. G., Tetzlaff, J., Mulrow, C., Gøtzsche, P. C., Ioannidis, J. P. A., Clarke, M., Devereaux, P. J., Kleijnen, J., & Moher, D. (2009). The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. Journal of Clinical Epidemiology, 62(10), e1–e34. https://doi.org/10.1016/j.jclinepi.2009.06.006 

Meira, E. (2020). Understanding evidence-based medicine using a funnel analogy. Society for Transparency, Openness and Replication in Kinesiology. https://doi.org/10.31236/osf.io/kr6aq 

Oxman, A. D. (2004). Grading quality of evidence and strength of recommendations. In British Medical Journal (Vol. 328, Issue 7454, pp. 1490–1494). https://doi.org/10.1136/bmj.328.7454.1490 

Sacket, D. L., Rosenberd, W. M., Gray, J. A. M., Haynes, R. B., & Richardson, W. S. (1996). Evidence based medicine: what it is and what it isn’t. BMJ, 312, 71–72.