An Attempt At Simplifying Central Sensitization

 

Have you ever had one of those appointments where you’re not sure of the outcome or the patient interaction?

I remember having a patient back in college who would come in for treatment of back pain. The person was in their early 20’s and told me they were dealing with chronic pain in the area. 

During the first treatment, as soon as I put my hands on them and pressed down, they quickly informed me that was too much pressure! So, of course, I backed off and used a much gentler touch. 

I felt like I was barely touching them. 

So, I treated the person a few times; then, they booked in with one of my classmates. 

However, during their treatment, the patient said “your treatment was okay, but you don’t use as much pressure as Jamie”!

We were both perplexed as my classmate said they were using very light touch (I think I had put something in the treatment notes about pressure). 

Neither of us could figure out what was the correct approach. There is a chance this was just therapist preference, but there’s also the possibility of something called Central Sensitization. 

Understanding Pain

It’s probably important to start by talking about Nociception. 

Nociception itself is not pain; it is the detection of noxious stimuli, which is a protective response that generates a reflex withdrawal to get us to stop doing whatever thing we are doing that could cause tissue damage. (1) Another result of this is it helps us avoid doing those things again (think the first time you put your hand on a hot stove, and will likely never do that again). 

When sensitization of this nociceptive system is repeated or more intense than usual, then the amount of stimulus needed to create pain decreases and becomes amplified. (1)

So, for Central Sensitization to occur, an intense stimulus has to happen repeatedly over an extended period. (1) Think of something like jabbing your forearm with a sharp pen for a couple of minutes (don’t actually do it, I’m just giving examples!). Doing the same thing with the pen for 5 seconds won’t have the same result. 

When this happens, it leads to Nociception no longer being a protection, and pain can arise out of nowhere. 

This can result in allodynia and hyperalgesia, and it is necessary to recognize the difference between the two. 

Hyperalgesia is where an increased response at a normal threshold or increased threshold creates an enhanced pain sensitivity. This is common for things like neuropathy. 

Allodynia is pain from something that shouldn’t be painful. Like the touch of a feather, as you can see in the image below.(2) 

 

Image from: Tsagareli, Merab. (2013). Pain and memory: Do they share similar mechanisms?. World Journal of Neuroscience. 3. 39-48. 10.4236/wjns.2013.31005.  

 

As well, pain can be exaggerated and prolonged because of its response to noxious stimuli and can spread to other parts of the body, which is called secondary hyperalgesia

The research papers cited show a whole host of molecular changes and activities in the spinal cord that lead to CS, but I’m not sure we have to know those specifics. It is important to know that these changes are happening in the dorsal horn of the spinal cord which is sending signals to the brain. 

Another essential takeaway is how there is no single defining mechanism; it’s a general phenomenon that changes how a stimulus is interpreted. 

So, how often have you had a patient come in where maybe their pain experience didn’t make sense? Perhaps their arm hit the door as they walked in, and it was excruciating? Maybe their description of what they are going through didn’t make sense? 

Well, this may be in part because of some CS occurring with them. Because tissue injury is not necessary, and pain can be maintained even though there isn’t any injury that has happened (recently), these may be signs that something more is going on. 

However, we aren’t able to diagnose this, but it may be vital for us to recognize it. So, let’s look at some conditions where this is common for people to experience this. 

What About Clinically? 

So, part of the issue with CS is that the CNS can change, distort, and amplify pain all without an actual noxious input. When we look at the lack of an injury, it may seem as though the pain isn’t real, but it most definitely is.(3)

So, imagine what this is like for the patient sitting in front of you. Especially when there could be things like work-related compensation etc. involved. (3) 

Another aspect regarding this condition is that it is complicated to diagnose because we cannot measure sensory input. So, pain hypersensitivity alone isn’t enough to say someone has CS. Some of the things they look at to determine if it is CS are (and remember how I said ‘a whole host of molecular changes and activities in the spinal cord that lead to CS, but I’m not sure we have to know those specifics’): (3)

  • pain mediated by low threshold fibres (but they have to use nerve blockers and electrical stimulation to figure that out)
  • spread of pain sensitivity to other areas without any injury
  • aftersensations (prolonged sensation after stimuli has been removed)
  • something called ‘temporal summation’ (basically things happening at the action potentials of nerve conduction)
  • pain continuing on from a small stimulus that usually wouldn’t cause pain

So, clearly, for us as Massage Therapists we wouldn’t be able to develop an accurate diagnosis for one of our patients, as much of this would have to be seen under MRI. 

However, we can look at some conditions where we are more likely to see this as CS can influence the following:(3)

Rheumatoid Arthritis

  • during flare ups more pain in the joints and remote areas could set up a state of CS

Osteoarthritis

  • degree of pain does not always correlate to extent of joint damage or active inflammation

Temporomandibular Issues

  •  associated with increase in generalized pain sensitivity after isometrics of orofacial muscles
  •  widespread bilateral mechanical and thermal pain sensitivity in women
  •  greater referred pain from trigger points
  •  mechanical allodynia with inflamed teeth, don’t become a dentist

Fibromyalgia 

  •  several studies showed increased sensitivity to pressure, thermal stimuli, and electrical stimulation of muscle and skin support CS
  •  they use medications in this case to treat the CNS

Musculoskeletal conditions

  •  Whiplash
  •  shoulder impingement syndrome
  •  tennis elbow (widespread bilateral mechanical pain)
  •  deep tissue hyperalgesia in chronic radiating low back pain, with intervertebral disc herniation
  •  characterized by spread of pain and sensitivity to deep uninjured tissue

Headache

  •  spontaneous body pain and allodynia preceeding migraine attacks
  •  chronic tension headaches referring to hyperalgesia of neck muscles
  •  CS may contribute to to chronification of tension headaches

Neuropathic Pain

  •  studies have looked at things like carpal tunnel that had enhanced bilateral sensitivity and spread of symptoms with nerve entrapment which supports CS

Complex Regional Pain Syndrome

  •  presents with increase in tactile and pressure invoked pain, presence of contralateral hypersensitivity in the absence of any inflammatory process

Post Surgical Pain

  •  depends on anasthesia and very important during recovery

Visceral pain

  •  IBS/referred pain – use local rectal anasthesia to help
  •  Non-cardiac chest pain have esophogeal  hypersensitivity   
  •  chronic pancreatitis – generalized deep pressure hyperalgesia
  •  urological tract hypersensitivity associated with: 
  •  interstitial cystitis
  •  chronic prostatitis
  •  endometriosis
  •  vulvodynia

Comorbidities

  •  fibromyalgia, tension headache, tmj, IBS
  •  no inflammation or cause which suggest CS
  •  good chance of genetic factors
  •  can contribute to depression, fatigue, joint pain

Okay I get it, that’s a LONG list. This post was intended to be a way to simplify what CS is, but there really are no ‘simple’ answers, especially for what we do to help patients. So there may not be a lot we can do treatment-wise, but what’s really important is to recognize what the person is going through. They may not get a CS diagnosis; they may not get any kind of diagnosis at all. 

And we know that patients (and insurance companies) really want to get a diagnosis to understand what is going on. So, our role may be to simply VALIDATE, VALIDATE, VALIDATE, the person sitting in front of us. You may be the first person who believes this person is in pain. Take the time to listen to them, let them talk, and support them! While you will likely have to adjust the pressure you use during treatment, those treatments may become supported self-management, and you may become their biggest ally for their journey. I don’t know to this day if that person I saw while I was a student had CS, I just hope I did a good enough job of minimizing their pain and feeling good, even for just an hour at a time. 

If you’d like to get more in-depth with the topic of Central Sensitization, Dr. Melissa Farmer has a great four-part series on the topic which you can read HERE

References

  1. Latremoliere A, Woolf CJ. Central sensitization: a generator of pain hypersensitivity by central neural plasticity. The journal of pain. 2009 Sep 1;10(9):895-926.
  2. Tsagareli, Merab. (2013). Pain and memory: Do they share similar mechanisms?. World Journal of Neuroscience. 3. 39-48. 10.4236/wjns.2013.31005.  
  3. Woolf CJ. Central sensitization: implications for the diagnosis and treatment of pain. Pain. 2011 Mar 1;152(3):S2-15

 

People Don’t Follow Guidelines For Back Pain Because There Is No Path To Follow

I get the opportunity to chat about back pain now and again around the world and one of the things I often talk about is the current guidelines around back pain. I will admit to often feeling a little apprehensive around this subject as the current guidelines run contrary to the way many HCP treat this common problem.

There is always a little gasp when manual therapy, acupuncture and ultrasound get relegated to adjunctive treatments. “Don’t shoot the messenger” is often my get out of jail card.

We know that clinical guidelines around most things within healthcare are not well followed. The big question is why?

We Are Humans!

Healthcare professionals are humans just like the people we are trying to help and suffer from exactly the same issues. For me there are parallels between getting clinicians to follow guidelines and getting people to be compliant, adherent, committed or whatever you want to call it to exercise programs or health improvement or even taking medications.

We all know that getting fitter is good for us as is reducing smoking, drinking and eating crappy foods. But that does not mean we always implement this knowledge. People still smoke and drink too much and don’t get the recommended dosages of exercise. Big societal messages are needed, but so is how to put them into practice at an individual level.

The big problem I see is how gigantically broad the guidelines are around treatment. Let’s take my favourite subjects’ activity & exercise, the guidelines are clear, movement is good, but the evidence base is not really clear when it comes to putting these recommendations into practice!

We might ask ourselves which exercise? How much? How should they do it? What should it feel like? Might it make the problem worse? How to get people to actually do it? If I look back at my clinical education in back pain treatment mostly it was based around Maitland mobilisations with little about exercise treatment and implementation.

So a simple guideline turns into a much greater clinical problem.

Providing A Path

Fundamentally we cannot expect people to implement something without giving them a way to implement it. We need to provide a pathway in much the same way we need to provide a pathway for the patients we work with around exercise.

How can you guide someone in something of you have no idea how to do it yourself?

Imagine getting a bit of flat pack furniture that did not come with any instructions. The pile of pieces that lay in front of you daring you to put them together. Some hardy souls, and probably those with a heap of previous experience, might attempt to put them together. Most normal folk, myself included, would simply put them back in the box and push them to the corner of the room. This conundrum is simply too much to handle.

You have all the pieces of the puzzle, but the problem is putting them together!

Education is another prime example. Education about what? Back pain? Pain? Treatment? Prognosis? All of the above? How to do it? Again there are many questions to unpack within the broad recommendation of education. I received no education in education at undergrad or post grad as I suspect neither have many of you reading this. Again this provides a barrier to implementation at the most basic level.

In the face of uncertainty and low confidence we return to our old habits that are ingrained within us and for many that is not based on current guidelines. Uncertainty provides huge inertia to change.

Support

Support is another factor that is often overlooked. How many people feel they cannot treat how they want to treat because of the working environment they are in and the people around them? This is something I often hear. Support again is a huge part of behaviour change and maintenance of that behaviour. A major part of self efficacy is built around social support and I doubt that it would be different in the work place.

The healthcare system that people work in can be a huge influencer of the way we practice in the same way our social systems affect our overall health and behaviours.

Takeaways

 

• Behaviour change is no different for HCPs than it is for patients

• If we want change we have to provide a path to change and support along the way

Beliefs, Communication, And How This Impacts Our Patients

I’m sure I’m not alone when I say I’ve seen some horrific things in my practice.

Now, when I say this, it’s not in the sense of major catastrophic injuries, or gory blood scenes, or something like that.

What I’m referring to is what I’ve seen and heard from patients as a result of what another well-meaning practitioner said to them. 

A patient comes in, sits down, and starts crying because another therapist told them they will never get better.

Another person who has been dealing with chronic pain for several years comes in and equates the pain they’re feeling in their back to a “rib being out”, or “their S.I. Joint is out again”.

And in the more extreme ranges someone giving up a career they love, in exchange for a job they hate because two people told them they would never be able to do their job again because of the surgery they just went through. In fact, told them if they continued doing the job they loved (and were very successful at), the surgery they just had would pale in comparison to the one they would need.

While I know none of these practitioners would intentionally have someone change their job, believe they won’t get better, or would constantly relate pain many years later to a simple biomechanical diagnosis, the reality is, their words changed people’s lives. 

And not for the better!

So, why then does this happen? Why are these enduring effects of words having such a dramatic impact on patients? And, more importantly, how do we stop this?

When Well-Meaning Beliefs Go Wrong

When we say “well-meaning” practitioners I do believe it’s just that. I doubt there are many out there legitimately trying to say harmful things to their patients (although I do believe there are some who use less than scrupulous language as part of the rebooking process).

So, when we have these well-meaning professionals saying things to patients, part of why they are saying the things they are is because they truly believe it (even if modern research refutes it). Part of the issue is when these belief systems are passed on to our patients it can have a lasting effect in a negative way. 

Unfortunately, many of these belief systems can come from continuing education courses that haven’t been updated in years and are still preaching these outdated belief systems.

A great systematic review (1) looked at several medical and paramedical professions to look at how their belief systems, (including biomedical and biopsychosocial treatment, fear-avoidance beliefs, and attitudes) affected patient behaviours.

There were several things that stood out to me reading through this(1):

  1. High levels of fear-avoidance in practitioners are related to the same fear-avoidance in patients.
  2. Practitioner beliefs are associated with the education they give patients.
  3. Practitioners with a more biomechanical base are more likely to advise acute pain patients to limit work and physical activity.
  4. Those with high fear-avoidance beliefs are more likely to recommend bed rest (which we know is not good for low back pain) and are also more likely to recommend this if seen in a media campaign.

Now I realize it probably sounds like we’re bashing anything related to biomechanical explanations here but honestly we’re not.

As we have said so many times over the years, biomechanics are still important, it’s just one piece of the puzzle. What I’m taking from this review is that if we’re strictly relying on biomechanical explanations we’re more likely to also cling to fear-avoidance beliefs as well, which isn’t doing our patients any good.

Part of the problem here is that if a practitioner has these beliefs, they get passed on to the patients we see. One of the major issues with this (as pointed out in the review)(1) is these beliefs result in persistent disability but not necessarily a change in pain.

So, if these beliefs are held, the patient’s pain won’t always change, but there is an increase in disability. Imagine your patients coming in for care and strictly because of a belief system, not only does their pain not get any better, but they become more limited in the things they can do. 

In light of all this information, I look back and think about early in my career and how I was saying very similar things to my patients. There comes a time when we have to sit back and ask ourselves whether the information we are conveying is correct, but also, is it in their best interest?

This review showed that even though some health care professionals believed in the biopsychosocial framework (it was originally introduced over 40 years ago), they were still operating from a biomedical orientation. In the case of doctors, they understood how important psychosocial factors can be yet, they lack the time to properly integrate this into practice.

So, while I look back on my career and cringe at some of the things I used to say, I look at this information and see how beneficial this is for us as Massage Therapists. If we embrace new research and change our beliefs, we not only have the time to spend with our patients, we have the opportunity to create lasting change for what they are going through. 

Words Matter!

So, now that we understand the influence of both the patient and therapist beliefs, the question remains, where did these beliefs come from?

Quite often these beliefs are because of lived experience, observing others in pain, or things that have been told to them throughout their life. A big influence was just not having a framework or a reference of what they should do when experiencing pain.(2)

All too often we see patients going to Dr. Google for advice, however, while this is usually looked at cautiously, people do place higher importance on the advice of friends and family.(2) While people would often seek out care from a health care professional, they would sometimes reject the advice given as they questioned their competence, and would even keep their own beliefs if it conflicted with the advice of a professional.

Now, this isn’t necessarily a bad thing because there’s nothing wrong with a patient using their own intuition to choose what course of action is best for them. It’s important for patients to feel confident in the information being presented to them, in fact, it’s even possible for their symptoms to be influenced by their interpretation of the education they are given.(2)

However, even if we believe we are giving them a very simple explanation of what is happening, there can be an enduring impact. I can now hear my mother’s voice resonating from my childhood and what she would say every time my brother and I would fight: “it’s not what you say, it’s how you say it!”

This paper has several examples of the lasting effect of what we say, which I think are important to highlight.

When a doctor gave a simple diagnosis of a sprain in an attempt to decrease the seriousness of the injury, the patient understood this to mean they had moved in such a way they had strained the muscle and they would make it worse by continuing to move the same way.

In the case of a person getting help from an orthopedic specialist, the result was well…horrific:

[The orthopedic specialist] looked at my back MRIs for a little while and turned around with a grin on his face and said, “You’re a builder, aren’t you?” and I said, “Yes,” and he said, “You’re [expletive], ha ha ha,” and went back to his computer again…. So, you know, I think that was his rather odd specialist way of breaking the news to me that I wouldn’t be working as a builder for very long…. Every time I felt a little bit wrong [after that], I started to sort of add it up in my head. And then my usual way of thinking, “Oh, that’s fine, that’s nothing, that’ll go away, that’s not major enough to stop me working, I’ll carry on [changed]”…him saying that was definitely the point, because I probably would have just carried on(2)

This person actually ended up changing careers as a result of what was said to them! Sadly as I mentioned, I’ve seen the same result in practice as well.

Another example that stood out to me in the same paper was equally as life-altering:

Basically all I’ve kind of been told to do by physios is to work on my core…I’ve been tested by various different physios, and Pilates, and I’m apparently ridiculously weak…. I had an abortion because I didn’t think I could have a baby. I didn’t think I could handle it…carrying it, and having extra weight on my stomach(2)

Can you imagine what this woman went through dealing with this?

Again, I’m sure these were well-meaning practitioners but when our communication is focused more on the things we can’t do as opposed to the things we should do can have compounding long-term effects. If we shift this line of thinking and encourage movement, provide reassurance, and show people how they are safe to remain active it can (and most likely will) have the reverse effect of the quoted stories we shared.

While many practitioners have a belief in the biopsychosocial model, many are still using biomechanical explanations of tissue damage, etc in an attempt to help their patients. As we have seen this can be detrimental to the patients well being. So it’s important to have a discussion around how to change these beliefs in practitioners. Many of us went through college and learned these things (I know I learned many of these explanations in school) and unfortunately, there are many continuing education courses still offering these kinds of explanations. This becomes our responsibility as a profession to change this, and really it starts with each one of us. It doesn’t even mean you have to spend thousands on new courses, it can mean just reading blogs like this, or a new research paper a week (it doesn’t take that long I promise), because we must change our beliefs in order to have a better impact on the people we are seeing in practice. When our beliefs (and our messaging) start to change we can slowly change our patient’s beliefs for better outcomes. Then, hopefully…hopefully, patients feel safe to return to their careers or have babies, or just return to an activity they love.

 

References

  1. Darlow B, Fullen BM, Dean S, Hurley DA, Baxter GD, Dowell A. The association between health care professional attitudes and beliefs and the attitudes and beliefs, clinical management, and outcomes of patients with low back pain: a systematic review. European Journal of Pain. 2012 Jan;16(1):3-1
  2. Darlow B, Dowell A, Baxter GD, Mathieson F, Perry M, Dean S. The enduring impact of what clinicians say to people with low back pain. The Annals of Family Medicine. 2013 Nov 1;11(6):527-3

Have We Ballsed Up The Biopsychosocial Model?

One of the most widely discussed topics in healthcare and especially in pain circles of late is the Bio Psycho Social model conceived by George Engel.  The BioPsychoSocial (BPS) model was developed in reaction to the dominant biomedical viewpoint that involves reducing medicine to specific diseases or pathologies that can be identified and treated and this model forms the backbone of most western healthcare systems.

Engel felt the biomedical model:

“does not include the patient and his attributes as a person, a human being”

But the question is, have we misinterpreted the BioPsychoSocial model?

Are we simply applying it in the same way as the biomedical model it was trying to replace?

It’s People Not Just Pathology!

We know that people’s experiences of pain and pathology differ. The same painful problem may manifest as huge issue for one person disabling them from work and reducing dramatically their quality of life, whilst another person may remain relatively unaffected. This has to be taken into account both in treating the problem but also how the person is TREATED by their healthcare professional, their family and social network and the wider healthcare system.

We can see below from Engel’s view that it is a bi-directional model that involves the layers in which we exist rather than discreet treatment targets as we now see.

Download 4We could perhaps determine this interaction between layers as the wider impact OF the problem rather than just as impacting ON the problem. Rather than seeing the BPS as a direct treatment model where we dissect the three domains to find new pain ‘drivers’ to treat, the BPS perspective should really be seen as a CLINICAL philosophy and guide that can be used for improved patient care.Here is another interpretation from a recent paper ‘How do physiotherapists solicit and explore patients’ concerns in back pain consultations’

“underpinning the bps model is patient-centred care (pcc) which involves incorporating the patient’s perspective as part of the therapeutic process”

One of the issues that are often encountered in healthcare however is that clinicians AND patients want solutions and treatments rather than philosophies and the conversion into a treatment model conforms to the biomedical perspective that dominates healthcare.

Maybe the BPS asks us, as clinicians to better understand our patients and their subjective experience? And it may be better defined as a model of care rather than a model of treatment. Now, this does not mean we cannot involve a BPS thought process IN specific treatment but remember that this is just not really the major focus of the model, certainly as I understand it anyway.

So it is really treating people and their overall existence, not just treating their painful problems. These differing aspects cannot just be separated and simply targeted without an understanding of the person and the context they exist in, doing that for me is the biopsychosocial model in biomedical clothing.

Other commentators such as Leventhal have looked at concepts such as the disease and the illness *HERE*. The disease being the specific issue and the illness being the wider issues surrounding the problem, in my interpretation, this is similar in concept to the BPS. How is this PERSON individually affected by the problem that may even BECOME the problem itself?

Just Treat The Pain?

I can already hear some readers shouting, “Just treat the pain – then you will not have any more problems”

Well, that is the biomedical view in a nutshell!

Firstly we have been attempting to do this for ages, hence why there has been a call for a different model. Often treatments for pain are not successful and people need help in other ways and we treat pathology but pain persists. Perhaps the interaction with healthcare even makes the problem worse!

Can we treat the person and pain? Yes, I believe so. We should not forget this, just realize our limitations at doing so and also avoid pain being the only focus.

The question is do we often attempt to treat the person AND the pain? I don’t think this happens as much as we would care to admit.  Maybe treating people rather than their pain can lead to reductions in pain? Maybe we cannot have an impact on people’s pain but affect suffering, disability, and quality of life? We may not be able to do this in a pain-focused model and why we end up with repetitive surgeries and the opioid epidemic?

People can still have pain and live a positive life; the BPS model is really well placed to help them do so and does life simply return to normal even after pain has reduced for all? I would hazard a guess that for many people their lives are fundamentally changed even AFTER persistent pain has decreased.

BPS Model Of Pain

A pain-oriented BPS model has emerged more recently and two examples of this can be found *here* and *here*. These interpretations should NOT be confused with Engel’s model I feel, and perhaps misses the essence of what he was reaching for. Maybe an issue with the BPS model is its breadth and how far-ranging it is? It is quite easy to place our interpretation anywhere within it.

The pain focused model looks at how Biological Psychological and Social factors can influence pain.

This diagram is a great example with the arrows pointing solely inwards.

Screen Shot 2019 08 21 At 07.34.26(Figure Fillingim 2017)
The problem here is that it is a return to a biomedical view in which the person is less of a focus and instead the disease (in this case pain) has returned to become the primary focus. Instead of being a comprehensive BI-DIRECTIONAL clinical philosophy, it has in many cases become a unidirectional treatment model.  We also have much more evidence for BPS aspects being associated with pain than we do actual data to support treatment for pain using these BPS aspects.Seeing PsychoSocial factors simply as pain influencing factors is missing the wood for the tree’s I feel. This would be a multifactorial pain treatment model, not the BPS model set out by Engel.This has drawn critique, and rightly so, of the BPS model and its interpretations. A recent paper from Stilwell and Harman can be found here called “An enactive approach – Beyond the BPS model”(Thanks to the authors for the full-text link!). This critique, I feel and highlighted by the authors, is not really of the Engel’s model but instead, the pain focused interpretation that has evolved. We may not need to move beyond the BPS model, more just apply it in its intended way. Let’s try to do that before we think beyond it.Stilwell and Harman go on to say

“Pain is…..a process that emerges or unfolds through a whole person who is inseparable from the world”

but we should also consider the BPS perspective already to consider the whole world and our existence within it and not just its effect on pain!

The very essence of the BPS model was NOT to delve further and further into the microscopic components of biology but instead to also zoom out to encompass the other factors that may be at play in both pain and quality of life.  I have written about this *HERE*. But if we consider most of the discussion, theories, and dominant messages around pain they focus on the reductionist view that Engel was trying to get away from.

As an example please insert any painful problem here ‘XXXXX’. Even the most uni-factorial biological one you can think of… let’s say a fracture.

How does their perception and knowledge, sense-making, around the issue affect them and their behaviors?

How does the injury affect their work and family life?
What are their perceived implications for the future?
How confident are they to return to sport or activity?

How motivated are they to engage in rehab or treatment?

This is considering the PERSON and heir engagement and embodiment in the world not just breaking down pain ‘drivers’ as the trend seems to have become and accusations of people forgetting the bio (eye roll).

Straight Lines & Trichotimies

Some of the criticisms of the BPS pain model focus on the division into three distinct components biological, psychological, and social as well as a perceived linear causality between the associated factors and pain.

My view of Engel’s work is that he objected to a linear causality model. Emergent properties such as pain NEVER have simple linear relationships with causes (whatever they are?). Again this is a misinterpretation and application specifically to pain of the original work. Linear causality is a criticism of previous Cartesian pain models but appears to be alive and well in the BPS.

The term ‘non-linear’ means that small things can give large effects but also large effects in one area may also give rise to no effects in the targeted area.  There are so many interactions occurring that can affect each other that the same treatment may give rise to DIFFERENT positive or NEGATIVE outcomes dependent on the current state of the organism.

We seem to be happier for this to be the case now biomechanically, but less so biopsychosocially. If we are being honest then we have many more associations WITH pain from what is termed BPS factors than actual data from using these factors to treat pain.

The trend of splitting pain into separates categories of Biological, psychological, and social to diagnose and treat is another critique that Stilwell and Hartman highlight in their paper and neatly term a trichotomy. I feel Engel’s point was not that they exist distinctly as pathologies to treat but in their own right but to consider these things within the wider appreciation of the patient’s experience.

Conclusion

  • We should really see the BPS model as a CLINICAL PHILOSOPHY and way of incorporating the patient into healthcare.
  • It is intended to understand patients, their lives, and contexts.
  • The biopsychosocial model COULD be used as a pain treatment model, but this is probably not how it was intended. This may be better termed a multi-dimensional pain treatment model.
  • There is not really much data on outcomes from treatment using a BPS pain model.
  • BPS factors are not simply linear treatment targets.
  • We may need to better apply the BPS model rather than move beyond it.