The Humble Beginnings of Pain Science

Pain is inescapable. Everyone has experienced it.

People go to great lengths to get rid of pain: high risk procedures, expensive drugs, and surgeries that carry alarmingly low success rates.

Many will resort to trying treatments they don’t even believe in. Despite all of our expensive and high risk options to reduce pain, and the infinite number of practitioners, theories, and methods to reduce pain, it remains not well controlled and not well understood in popular society.

In this article I will introduce you to pain theory models, discuss some of the common problems with how we think of pain, bring in contemporary thinking with the biopsychosocial model of pain, explain how words can influence pain, and provide suggestions on how fitness professionals and physical therapists can assist their clients who may be in pain.

Pain Theory Models: a brief history

Imagine you just stubbed your toe.

Your initial reaction is probably to drop a few F bombs, maybe hop around the room for a second. Once you get past that initial pain, you start thinking about what just happened. Chances are, you have experienced the intense pain of a stubbed toe. You can anticipate how long it will hurt for, you know exactly why it hurts, and most importantly, you know that the pain will go away- you didn’t do any permanent damage.

This cause and effect model of pain is called the Cartesian Model, popularized by the philosopher Descartes in the early 17th century. It makes sense in theory: You have a culpable source for pain, and a resulting outcome. When this model is applied to biomechanics it says, If you fix the source of pain, you can stop the pain.

 


Models-of-Pain1.png

 

Unfortunately, it’s just not that easy. Contrast that stubbed toe to chronic back pain. The pain experiences couldn’t be further apart.

Typically with low back pain the cause or etiology is unknown. Research has already demonstrated that the clinical presentation and MRI diagnostics do not correlate well (4).

Low back pain can vary over time, sometimes it’s not-so-bad, other times it can be unpredictable and debilitating. It’s incredibly common, but not well understood and surrounded by a whole host of misconceptions. 

All of these experiences I have outlined with chronic low back pain can contribute to the present day model of how we understand pain, the bio-psycho-social (BPS) model.

“In modern medicine, the Cartesian or nociceptive concept of chronic pain has been replaced with the biopsychosocial model in both theory and practice (1).”

The Biopsychosocial Model of Pain

“The late George Engel believed that to understand and respond adequately to patients’ suffering… clinicians must attend simultaneously to the biological, psychological, and social dimensions of illness”(2)

George Engel proposed the bio-psycho-social (BPS) model of illness in 1977 out of a perceived necessity to understand how contemporary models were unable to accurately explain the pain experience. Engel knew there was more to patients’ illness than the biomedical and biomechanical models. Despite advances in surgery and medicine, Engel was ahead of his time in observing a blind spot in medicine. He knew there was a subjective component being ignored.

Engel did not deny that the mainstream of biomedical research had fostered important advances in medicine, but he criticized its excessively narrow (biomedical) focus for leading clinicians to regard patients as objects and for ignoring the possibility that the subjective experience of the patient was amenable to scientific study.

 


https://www.lewespainclinic.co.uk/single-post/2018/11/12/Biopsychosocial-Health

https://www.lewespainclinic.co.uk/single-post/2018/11/12/Biopsychosocial-Health

 

Engel formulated the BPS model as a response to 3 trends he saw in medicine:

1.Dualism

Engel criticized the dualistic nature of the biomedical model, with its separation of body and mind. He emphasized the importance of considering the entire patient rather than just the disease itself.

2. Reductionism 

Engel criticized reductionistic medical thinking: anything that could not be objectively verified and explained at the level of cellular and molecular processes was ignored or devalued. He saw this as short sighted and knew not all illness could be quantified.

3. The Detached Observer

The third element Engel brought to light was the influence of the observer on the observed. Engel correctly hypothesized that the disposition or affect of the medical caregiver would inevitably influence the patient

If we summarize the 3 trends Engel observed in the context of chronic back pain. You will see how these can have a negative impact on how the patient perceives their pain and sense of control.

The dualism model fails to address all potential causes of low back pain by ignoring research that shows links between depression, a sedentary lifestyle, and low back pain. In contrast, it would be prudent for a medical practitioner to broach these sometimes difficult topics in order to comprehensively address the patient’s needs.

The reductionism model would have the patient believe their misaligned sacrum or herniated disc are structural problems causing them pain. And they can’t ever fix them or feel better without surgery. This has now removed the patient’s locus of control.The postural-structural-biomechanical model of pain, while helpful at times for treatment, has not been shown to reliably predict pain, injury, or dysfunction.

The detached observer model would represent professionals telling patients everything that’s wrong with them, giving them a false sense of negativity, and having poor bedside manner. Observers, or medical providers in this case, oftentimes detach themselves from their patients emotionally as a coping mechanism and response to a high frequency of emotionally taxing interactions. Whether it’s reading MRI results, or just noting small observations, our words and disposition can have a negative effect on a patients’ ability to control their own pain. 

How should the bio-psycho-social model impact clinical treatment?

For the average person or patient, they don’t need to know George Engel or pain science.

They may benefit from simply understanding that pain is complex and multifactorial. And for many, that exact wording may not resonate or be relatable for them.

Patients need confidence that they can get over this pain, and they need education about how to slowly work towards their goals. They need solutions, not more problems.

For example, take the inactive or older person, they might benefit from knowing things like their mood and physical activity levels can influence their pain.

For more active people, they might benefit from learning that nutrition, sleep quality, and stress reduction activities can impact their pain.

And lastly, for the highly inquisitive smart ass, they might enjoy hearing about the fascinating research on pain signaling in the brain, central sensitization, or watching Lorimer Moseley’s talks on YouTube.

The goal of clinicians and fitness professionals should be to help empower patients to control their own pain. They have a responsibility to explain to their patients and clients that pain, muscle tone, and tight muscles are the result of an interplay between the brain and the body, and sometimes these nerve signals fire incorrectly.

Even though things go wrong sometimes, they usually get better pretty quickly and respond well to physical therapy and exercise. This doesn’t mean you need to justify the exercise by convincing them you’re fixing their terribly flawed posture.

Instead of using biomechanics to scare patients and clients, responsible clinicians and trainers should use their knowledge of biomechanics to create individualized plans in congruence with the fitness level and needs of the patient. Let’s not be victim to those brain signals anymore.

Let’s educate our patients.

Special thank you to Lars Avemarie for bringing to light my mistake in the original publication of this article on teddywillsey.com. To clarify, the late George Engel’s work was in proposing the bio-psycho-social model of illness. This was used as theoretical framework and later adapted to pain by William Fordyce in 1988.

References

1. Goldberg JS. Revisiting the Cartesian model of pain. Med Hypotheses. 2008;70(5):1029-33. Epub 2007 Oct 29.

2. Borrell-Carrió F, Suchman AL, Epstein RM. The Biopsychosocial Model 25 Years Later: Principles, Practice, and Scientific Inquiry. Ann Fam Med. 2004 Nov; 2(6): 576–582.

3. Lima DD,  Pereira Alves VL, Turato RE. The phenomenological-existential comprehension of chronic pain: going beyond the standing healthcare models. Philosophy, Ethics, and Humanities in Medicine. 2014, 9:2

4. Boden SD. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am. 1990. 72(3): 403-408.

5. Tetsuo, Masui. Natural history of patients with lumbar disc herniation observed by magnetic resonance imaging for minimum 7 years. Journal of Spinal Disorders and Techniques. 2005: 18(2): 121-126.

6. Borenstein DG. The value of magnetic resonance imaging of the lumbar spine to predict low back pain in asymptomatic subjects: a seven year follow-up study. J Bone Joint Surg Am. 2001. A(9): 1306-1311.