As a PT, I am fascinated by the concept of pain and my first article for the sportEX blog (June 2011) is a reflection on the concept that pain itself may not always be a symptom, but instead, a disease. In my opinion, the article I have reviewed, written by G. Lorimer Moselely, highlights a concept that is often ignored by those in our field. We are trained early on to fix movement dysfunctions and research is now telling us that certain movement dysfunctions may be secondary to the output of pain. I find this concept fascinating and wanted to start the discussion with fellow professionals.
As physiotherapists, we routinely see patients who present to our clinics with complaints of persistent, chronic pain. These patients are often dissatisfied by other clinicians who have simply dismissed their complaints due to negative diagnostic imaging, clinical patterns that don’t make sense and lengthy rates of healing. As “movement experts”, we often assume that pain is due to a limitation in movement and by allowing one to move better, pain will resolve. But what if in reality, the issue wasn’t pain resulting from movement limitations but the opposite. What if the movement limitation happened as a result of pain? Recent neurophysiologic literature is tackling this “chicken and the egg” debate and suggests that some of the patients we see may not be experiencing pain as a symptom, but instead a disease.
I want to begin this journey by first defining pain and why it exists. The International Association for the Study of Pain (IASP), defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”. While thinking about this definition, I find the term “potential” to be peculiar. The authors of this description state pain does not have to exist in the presence of true tissue damage, but can occur due to the “potential” for damage.
Wanting to understand this concept further, I reviewed an article by G. Lorimer Moselely entitled “A pain neuromatrix approach to patients with chronic pain”. After reading this, I have concluded that this article is instrumental in cross-linking the neurophysiology behind pain with how clinicians should approach the care of individuals with chronic pain. He describes chronic pain itself as having associated signs and symptoms and describes it as an experience that is unpleasant, demands attention, reduces cortical processing capacity, slows decision-making, increases cognitive error, and modifies immune activity. He highlights that chronic pain is a condition, not just a symptom, which should not be taken lightly.
Moseley describes the pain neuromatrix, which is the combination of the cortical mechanisms that when activated, produce pain. The concept of the neuromatrix, which was first proposed by Ronald Melzack, is described as a network of cells that produces a perceptual and motor output that can exist with or without an input. In the treatment of individuals with pain dominant conditions, one must understand that pain exists as a multiple system output that is activated in an individual-specific neuromatrix. The output occurs when the brain perceives a tissue is in danger, not just when the tissue is in danger (supporting the earlier description by the IASP).
In this statement, consider some of your own patients who present with chronic pain. Consider those whose patterns aren’t consistent with what we understand as “movement experts”. Consider those who “feel” pain by just watching someone else perform a task. Consider those who do fine with stabilizations exercises in the clinic but report the pain returns when they go to work. Consider those with major injuries, who experience minimal pain and those with minor injuries, who experience intense pain.
Most of us can name a patient that we are currently seeing that is described in each of these examples, but how many times did you consider their tissues may well be intact but their brain is perceiving “tissue danger” and sending a pain output signal? Moseley further reports that pain may be context-specific, work-specific and posture specific. So in the treatment of our patients we must take into account when their pain occurs, to what extent it occurs and what we can do to modify the threat. He believes we must attempt to change the cognitive-evaluative inputs of a threat and by doing so, we may successfully treat a condition which we were unable to treat prior. Treatment and progression may simply begin by attempting to perform imaginary movements (ie. Imagine moving that painful arm…can you do it?), progress to gently breaking a motion into its components, moving the body part in a painfree manner and gradually progressing the patient to performance of the motion in different environment, contextual, and/or postural frames of reference.
Overall, Moseley has described the key principles we should consider when treating individuals who present to our clinic in pain. The therapeutic approach in the care of these individuals should not be to simply improve strength of the core or apply useless modalities, but to instead focus on reducing the activity of the pain neuromatrix (ie. reduce the perception of a threat).
References
- Merskey H, Bogduk N. Classification of Chronic Pain. 2nd ed. Seattle: IASP; 1994
- Moseley GL. A pain neuromatrix approach to patients with chronic pain. Manual Therapy 2003;8:130-140
- Melzack R. Pain and the neuromatrix of the brain. Journal of Dental Education 2001;65:1378-1383
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