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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.

Spondylolisthesis

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

References:

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

Plato Part 1 – Broad shoulders are needed to move philosophy

Welcome back, awesome nerds. I continue my journey through philosophy, in this text reaching the very famous philosopher that was Plato. He is often considered the most influential philosopher in history, with his philosophical ideas shaping even most Christian theology and philosophy (Russel, 1946). Thus, whenever we are looking at the history of philosophy, he and his ideas are an obligatory stop. Before taking a general look into the many ideas Plato presented us with, let’s start by learning a bit more about him as a person.

Plato is said to have been born around 428-7 BC (Adamson, 2014; Kenny, 2010) into an aristocratic Athenian family, with some of his relatives being among the Thirty Tyrants of Athens (Kenny, 2010; Russel, 1946) Plato is also said to have fought in the Peloponnesian War with two of his brothers (Kenny, 2010). A neat bit of trivia is that the name “Plato” was actually a nickname, that came from the Greek platus, meaning ‘broad’ or ‘large’, with his real name being Aristocles. The nickname supposedly came from one of the following three reasons, or all of them: Plato being physically so well-built due to also being a wrestler, from the wide breadth of topics in his writings, or just because he had a large forehead (Adamson, 2014). To avoid confusion, I will continue to call this philosopher by their widely known nickname.

As mentioned in a previous text, Plato was a student of Socrates. At the time of the latter’s death, Plato was in his late twenties and had been his pupil for approximately 8 years (Adamson, 2014; Kenny, 2010). This had a significant impact on Plato’s world and political view, as besides being a pupil of Socrates, he also had a profound respect and affection for him. Thus, Socrates being sentenced to death by democracy, together with the influence of his social position and family, led to Plato despising democracy (Russel, 1946).

Besides Socrates, the other significant influences on Plato’s philosophy were said to have been Pythagoras, Parmenides, and Heraclitus (Adamson, 2014; Russel, 1946).

From Pythagoras, Plato is said to have kept what are known as ‘Orphic’ elements: a religious trend, the belief in immortality and other-worldliness, and a respect for mathematics, all this in an intermingling of intellect and mysticism (Russel, 1946). This can be seen in Plato’s opinion on the type of education necessary to make a good ruler: he thought that without mathematics no one could achieve true wisdom and that some of Greece’s tyrants would have been better rulers if they had learned geometry (Russel, 1946).

Parmenides influenced Plato’s belief that reality is eternal and timeless,  and thus, any perception of change will be illusory (Russel, 1946). In contrast to this, from Heraclitus Plato took the notion in the sensible world nothing is permanent (Russel, 1946). The synthesis of these two doctrines led Plato to hold that true knowledge cannot come from the senses, but only be gained intellectually. (Russel, 1946).

From Socrates, we can say Plato inherited his focus on ethical problems and using the notion of “The Good” to guide his reasoning – thus seeking to explain the world through purpose as opposed to more mechanical explanations (Russel, 1946).

Together with being a philosopher, Plato was also a great writer, being able to show much imagination and charm in his written works (Adamson, 2014; Russel, 1946). These written works were mainly in the form of dialogues, which Plato is said to be the first to use in philosophy (Adamson, 2014), and are how we have access in present-day to Plato’s philosophical ideas. We seem to be lucky to the point that all written works that have in antiquity been attributed to Plato have survived until the present-day (Kenny, 2010). Some authors suggest that Plato wrote in dialogues because he believed that you could write the theory of a philosophical idea in a book, but you could not actually pass on or understand the actual idea in the same way (Adamson, 2014). He believed that true philosophy happens during the discussion between a teacher and student (Adamson, 2014). This is because, though written words are prone to be misunderstood or distorted, in an in-person discussion one can explain ideas, respond to critiques and clarify misunderstandings (Adamson, 2014). Plato settled for a middle ground: he wrote his ideas but wrote them in the form of dialogues (Adamson, 2014).

This choice of writing style offered Plato benefits but presents us with some problems in trying to understand Plato. For Plato writing in dialogues helped him developed his philosophical ideas, as taking a third person perspective helped him present the strongest arguments he could come up with for both sides of the ideas he presented (Kenny, 2010). However, because Plato himself never participates in the dialogues he writes, it makes it difficult for us to understand from among all the philosophical ideas presented throughout the texts, which come from the character or figure expressing them, and which actually come from Plato – a notable example being Plato’s Socrates (Adamson, 2014; Kenny, 2010).

Usually, scholars will group the Platonic dialogues into early, middle and late periods, through a striking correspondence between dramatic, philosophical and stylometric sets of criteria (Adamson, 2014; Kenny, 2020). This division was achieved through the way some dialogues reference another one in their philosophical content, analysis of the role attributed to Socrates, as well as statistical analysis of style of writing (Adamson, 2014; Kenny, 2010) – I didn’t even know this last one was a thing. According to this division, Plato started writing close to Socrates’ execution, with the dialogues in the “early period” being shorter and somewhat adhering to Socrates’ practice in discussion: Socrates is described as questioning about a certain concept together with someone, the concept usually being a virtue like piety or courage, but ultimately both fail to achieve clarity at the end (Adamson, 2014). This period includes the dialogues of Lysis, Apology, Crito, Charmides, Laches, Ion, Euthydemus and Hippias Minor (Kenny, 2010).

Following this comes the “middle period”, during which Plato wrote more ambitious, longer works, and moved away from representing typical Socratic encounters (Adamson, 2014). In these dialogues, Socrates also changes his role from someone who questions others to a teacher with a fully established system of philosophy, which is believed to represent Plato’s own philosophy instead of Socrates’ (Kenny, 2010). This period includes the dialogues of Phaedo, Republic and Symposium (Kenny, 2010).

Finally, there were the “late” works, which often tended to be more technical and less dramatic in their setting. Often there is one lead character who controls the discussion by taking advantage of an interlocutor who doesn’t give him much trouble. In this later period, Plato also often reduces Socrates role to a minimum and allows other characters to take the leading role (Adamson, 2014; Kenny, 2010). This period includes the dialogues of Philebus, Critias, Sophist, Statesman, Timaeus and Laws (Kenny, 2010).

Throughout this body of texts, we can find what are considered to be the most important ideas in Plato’s philosophy (Russel, 1946):

  • The Theory of Ideas.
  • Immortality.
  • The idea of a Utopic Society
  • Plato’s cosmogony, or how he believes the universe originated.
  • The idea that knowledge is something to be remembered (reminiscence) instead of acquired.

Focusing again more on his life, when Plato was about 40 years old he founded a philosophical community close to his house, named the Akademeia – this is where we got the word ‘Academy’ from (Adamson, 2014; Kenny 2010). There, a group of thinkers would, under Plato’s instruction, debate and share their interest in mathematics, astronomy, metaphysic, ethics and mysticism (Kenny, 2010). And finally, Plato is said to have died peacefully at a wedding feast in 347 BC, at the age of 80 (Adamson, 2014; Kenny, 2010).

Concluding, many central debates in philosophy, such as the immortality of the soul or the nature of language are for the first time presented by Plato (Adamson, 2014), and as we explore some of his dialogues in future texts, we will see how these philosophical doctrines will be developed. Interestingly, despite being often considered his most famous doctrine, throughout the dialogues, Plato’s Theory of Ideas is rarely clearly stated or explained (Adamson, 2014). We will also see that the Sophists will play a major role in a lot of Plato’s dialogues (Adamson, 2014).

However, Plato is not without his flaws. Russell (1946) has presented the critique that often Plato is not quite intellectually honest. He judges doctrines based on their social consequences but during his dialogues often pretends to be judging the argument and following to its conclusions based on theoretical or logical standards. In reality, he is often concerned with arguing for what he thinks are the characteristics that make someone virtuous and twisting the debate with this end – a habit he introduced into philosophy, which has lasted until the present day (Russell, 1946). Russel (1946) also argues that this bias, together with Plato’s genius as a writer, allowed him to present illiberal, and sometimes even tyrannical ideas, in a way that made them be admired by future generations.

With the background set, in the next text, I will start to delve a bit deeper into each of Plato’s most influential ideas and their corresponding dialogues, hopefully illustrating how these influenced a lot of the common ideas in contemporary society.

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

The Physiolosopher

References:

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.

Management of Spinal Stenosis – Is there space for improvement?

Welcome back amazing nerds.

In the previous post we discussed what is spinal stenosis and what can contribute to or cause it. Now that we understand what this condition is, I’m going to take you through what the available research says about its treatment and management. Before I start, I want to again highlight that these texts have the goal to inform, not diagnose or in any way substitute or equal a thorough assessment by a healthcare professional. So, if you’re in doubt, book an assessment with a qualified physiotherapist.

With that out of the way, let’s look at how to manage spinal stenosis.

Non-surgical Management

The general consensus is that management should start with non-surgical interventions. This includes interventions such as medication, lifestyle modification, physiotherapy, or multidisciplinary rehabilitation (Ammendolia et al, 2022; Wei et al, 2021). This is because many cases of nerve pain, even those where neurological symptoms such as pins and needles are present, will resolve even without intervention (McCartney et al, 2018).

Exercise appears to be a core modality in the management of stenosis at both the level of the neck and lumbar spine, with physiotherapy being the main discipline guiding this intervention (NICE, 2020; NICE, 2022a). Even when other treatment options are mentioned such as manipulation or soft tissue techniques, these are only recommended if they are part of a management plan that includes exercise (NICE, 2020; NICE 2022a).

If we are wondering about the effect of combining these therapies, some studies have looked at benefits of combining manual therapy with exercise to supervised exercise and to home/group exercises (Temporiti et al, 2022). They found that manual therapy plus exercise appears to provide more benefits for pain, walking ability and quality of life than home or group exercises, however no differences were found when comparing this manual therapy plus exercise to supervised exercise, even after 1 year post intervention (Temporiti et al, 2022). Because manual therapy was never compared on its own to other interventions, we don’t have evidence on its effects for spinal stenosis, with the only high quality study on this so far not finding any benefit to patients (Temporiti et al, 2022).

Even in multidisciplinary rehabilitation, exercise continues to play a core role. Multidisciplinary interventions could include something like psychological therapies – due to, as we have touched on before, pain being multifactorial (Ammendolia, 2022) – but should still only be considered if part of a management plan that includes exercise (NICE, 2020).

But now you may be asking yourself: what type of exercise is better?

A review by Temporiti et al (2022) tried to answer this exact question. Their findings suggest that supported body weight walking appears to be better at reducing pain and disability compared to usual body weight exercises but cycling appears to be better than both in reducing disability. When we look at aquatic exercises, such as those performed in hydrotherapy, these also appear to improve pain and walking ability more than land-based exercises (Temporiti et al, 2022).

Moving on to medication, for stenosis of the neck, oral and topical NDAIDS – think Ibuprofen, Naproxen, Diclofenac and similar (NICE, 2022b) – are suggested in cases that are struggling to cope with their pain (NICE, 2022a). As you can see, it’s not mentioned you immediately need them or that you need to have them at all if you can cope with your pain while receiving other forms of treatment.

For cases of stenosis linked to the lumbar spine, we find that we actually don’t have enough research showing there is benefit with NSAIDs for nerve pain and medications such as Gabapentinoids, oral corticosteroids or benzodiazepines are recommended against for this same type of pain (NICE, 2020)

A more specialised form of medication administration is injections. Epidural injections can be considered in acute cases of nerve pain, but are generally recommended against, particularly in cases of neurogenic claudication caused by stenosis of the central spinal canal (Ammendolia, 2022; NICE, 2020).

Now looking at less conventional management options, we don’t appear to have sufficient quality on clinical trials to reach a clear conclusion on the use of acupuncture and spinal manipulation for lumbar stenosis (Ammendolia et al, 2022).

Often we also hear about different machines that supposedly help with pain. When we look at studies comparing their effectiveness,  we find that there was no difference between ultrasound and fake ultrasound, and no benefits for the use of TENS (Temporiti et al, 2022). A big limitation that this review found in studies relating to these modalities was that there is a very small number of studies available from different interventions, which only follow up people for a short amount of time, and for the overall included studies there is a lot of differences in design and intervention between studies, all of which greatly limit the conclusions we can make (Temporiti et al, 2022).

If you want to know how I interpret these results, I’m reading that doing something is better than doing nothing at all, and that exercising is better than no exercising, as it improves more outcomes than other interventions with likely less risks. Exercise also appears to be better when supervised instead of just giving people a sheet of exercise, and manual therapy still needs to show proof of its benefits. Besides that, currently, it’s not wise to put our hopes in gadgets to help patients.

Lastly, imaging modalities such as MRI have a role when symptoms include objective changes to neurological functions and have been persisting for over 6 weeks, but only if imaging is likely to change management (McCartney, 2018; NICE, 2020; NICE, 2022).

Surgical Management

Moving on to the dreaded, or sometimes very hopeful, option of surgery, we need to keep in mind that there should be an appropriate reason and timing for an intervention to be used.

Spinal decompression can be considered for people with nerve pain, with origin linked to either neck or lumbar spine, when non-surgical management was not helpful, or symptoms have worsened, and there is correlation between the person’s symptoms and findings on imaging (Davies et al, 2018; NICE, 2020; NICE 2022a).

The aim of surgery should generally be to reduce the mechanical compression on either the spinal cord or nerve, and thus spinal fusion or disc replacement procedures are recommended against (Davies et al, 2018; NICE, 2020).

The use of surgery is supported by some small studies that for pain associated with cases of lumbar stenosis, in both short and long-term, surgical interventions appears to be more beneficial than non-surgical options (Wei et al, 2021). However, these findings are contradicted by more recent reviews and surgical management does not appear to outperform non-surgical options in improving function, which, together with the limitations of the mentioned studies, means we should take these findings with some skepticism (Kirker et al, 2022; Wei et al, 2021).

In addition to this, a more recent review by Ammendolia et al (2022) suggests that we lack high-quality evidence for the general effectiveness of surgery in cases of stenosis of the lumbar spine.

What works better?

A significant barrier to providing better management of lumbar spinal stenosis is that a lot of the studies comparing the effectiveness of different types of interventions such as physiotherapy, injections, medication or surgery appear to be of overall low-quality (Kirker et al, 2022).

In a review by Kirker et al (2022), when comparing rehabilitation with no treatment or placebo, the former did not show proof of being more effective. However, I am somewhat sceptical to this conclusion, due to obvious professional bias, but also due to the fact that interventions of just acupuncture, which are obviously unscientific and dubious, were considered as part of rehabilitation for comparisons  in this review (Kirker et al, 2022). This is not surprising as a sadly a significant number of physiotherapists apply these and other unscientific, borderline esoteric and non-evidence based interventions in their daily practice.

Lastly, the authors suggest that as no conclusions can really be made either way, but surgical treatments have a higher rate of more significant side effects, as well as significant re-operation rates, a trial of conversative treatment is first applied as it appears to have similar benefit (Kirker et al, 2022). But I recommend you skip the acupuncture in this case.

I hope this text has given you some more information about what research currently tells us about the management of cases of spinal stenosis, how different options compare and what can inform the timing of choosing certain options over others. Spinal stenosis can sound like something very scary on paper, so I would argue that understanding it and the options we have to help manage it are key.

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

The Physiolosopher

References:

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

Davies, B. M., Mowforth, O. D., Smith, E. K., & Kotter, M. R. N. (2018). Degenerative cervical myelopathy. BMJ (Online), 360. https://doi.org/10.1136/bmj.k186

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

Kirker, K., Masaracchio, M. F., Loghmani, P., Torres-Panchame, R. E., Mattia, M., & States, R. (2022). Management of lumbar spinal stenosis: a systematic review and meta-analysis of rehabilitation, surgical, injection, and medication interventions. In Physiotherapy Theory and Practice. Taylor and Francis Ltd. https://doi.org/10.1080/09593985.2021.2012860

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

NICE (2020, December). Low back pain and sciatica in over 16s: assessment and management. NICE- National Institute for Care Excellence. www.nice.org.uk/guidance/ng59

NICE (2022a, March). Neck pain – cervical radiculopathy. NICE – National Institute for Care Excellence. https://cks.nice.org.uk/topics/neck-pain-cervical-radiculopathy/

NICE (2022b, September). Non-steroidal anti-inflammatory drugs. NICE BNF – National Institute for Care Excellence British National Formulary. https://bnf.nice.org.uk/treatment-summaries/non-steroidal-anti-inflammatory-drugs/

Temporiti, F., Ferrari, S., Kieser, M., & Gatti, R. (2022). Efficacy and characteristics of physiotherapy interventions in patients with lumbar spinal stenosis: a systematic review. In European Spine Journal (Vol. 31, Issue 6, pp. 1370–1390). Springer Science and Business Media Deutschland GmbH. https://doi.org/10.1007/s00586-022-07222-x

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

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

References:

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

References:

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.

References:

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.

References:

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.

References:

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.

J

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.

References:

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