Chronic pain is a complex and distressing problem. Unlike acute pain, which is well associated with injury, chronic pain is often unrelated to tissue damage. A wide variety of factors like sleep, mood, thoughts, or emotions tend to have an effect on chronic pain and it can also be connected with other health problems like obesity, anxiety, depression, or IBS and can even be determined by things like past experiences, past memories, and learnings (conditioned pain).
In this blog, I will try to simplify one of the many ways our body responds to chronic pain.
To begin with;
How Do We Define Pain?
According to the International Association for the Study of Pain (IASP), pain is defined as “An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.”
What does this definition really mean?
I’d like to point out two factors. First, is the word “experience”. Pain is more than just having body parts that hurt. It involves the emotional experience associated with it. This may include fear that it might be permanent or the affliction of missing out on social events or things you enjoy because of it (stepping stone to conditioned pain).
Second, in the definition above, you must have noticed that it’s associated with “actual or potential damage.” This means that, yes, you can have pain without any physical tissue damage at all.
Now, coming to learning.
Learning is defined as the process of acquiring new understanding, knowledge, behaviors, skills, values, attitudes, and preferences.
Well… what does learning have to do with chronic pain?
We’ll try to correlate the two using Pavlov’s theory of classical conditioning.
In the famous conditioning experiment by Pavlov, it was observed that the salivation in the dog was a learned response. The dogs were responding to the sight of the research assistants’ white lab coats, which the animals had come to associate with the presentation of food. Salivation to the expectation of food is a conditioned reflex.
Likewise, a movement that isn’t causing nociception produces pain because humans learn to associate pain with movement i.e. it becomes a conditioned pain response to movement.
The table below tries to establish a brief relationship between the two:
The brain contains widely distributed neural networks that create an image of self through memories of past experiences.
Afferent inputs act on these memories and produce output patterns that lead to the report of pain.
Stress can change the interactions between memories and peripheral stimuli, as can learning experiences and expectations.
Clinically significant acute pain always involves tissue damage; the central and peripheral nervous systems are dynamic and are modulated by tissue damage and changes in stress-regulation systems that occur in response to such damage.
Although; most of these modulations are of short duration, some may persist and lead to chronic pain states.
So the question that arises now is how do we resolve conditioned pain?
The answer is simple, the way one learns to associate movement with pain is a gradual process of constant reinforcement by self-research (internet searches) nocebic communication and various narratives spread around pain and movement,
similarly; one can ‘slowly’ learn to disassociate the same by progressively exposing themselves to stress and movement, both well tolerated and poorly tolerated, in order to make them less sensitive to it, a.k.a. Graded exposure
Breaking down the words; graded meaning to separate people or things into different levels of quality, size, importance (here, activity), and exposure implying the fact of experiencing something or being affected by it because of being in a particular situation or place.
Pain is a symptom, not a cause, and our experience of pain is determined by our past experiences, beliefs, fears, etc. therefore people learn to associate non-nociceptive(not painful) stimuli with pain,
Hence, pain isn’t always indicative of the presence or extent of the damage.
Imprecise encoding of the original painful event, which may be, for example- bending forward (stress) in people with back pain results in the generalization of back pain to similar movements and activities.
At some point of generalization, the protective function (avoiding forward bending) moves from being adaptive or helpful to being maladaptive or unhelpful,
This is when graded exposure helps us gradually return to movements (forward bending) that were painful initially and helps us unlearn.
Here’s a metaphorical analogy to illustrate.
If you drop a frog in a pot of boiling water, it will of course frantically try to clamber out. But if you place it gently in a pot of tepid water and turn the heat on low, it will float there quite placidly. As the water gradually heats up, the frog will sink into a tranquil stupor, exactly like one of us in a hot bath, and before long, with a smile on its face, it will unresistingly allow itself to be boiled to death.
Equivalently, when we expose our already sensitive nervous system to a high amount of stress suddenly, it freaks out and responds with pain.
And, when exposed gradually using an appropriate dosage of exercise and time our nervous system holds the capability to adapt to the imposed stress and this eventually helps us to get back to doing the things we could do pre-injury.
A real-life example of the same would be when people with low back pain are told to bend from their knees rather than from their backs to lift things up from the floor initially; when bending forward is an exaggerating factor for their pain (which is often misunderstood as a lifelong modification by the patient) and as their symptoms improve the movement of bending forward is gradually re-introduced (the need to perform a modified movement beyond its necessity is a doubt that’s often left hanging leading to kinesiophobic behavior and unfruitful graded exposure)
Therefore, a major goal of any program for rehab should be to make the nervous system more adaptable and less wary about the state of the body and reinforce its ability to withstand the stress of movement which can be accomplished by listening, educating, and reassuring the patient, symptom modification & graded exposure.
In conclusion,
We can summarize graded exposure in 3 simple steps:
1)Identify the painful movement(s)
2)Modify it initially to decrease pain
3)Gradually progress the movement(s) again
In the words of George Leonard,
“Resistance is proportionate to the size and speed of the change, not to whether the change is a favourable or unfavourable one.”
It’s like building muscle. If the weight is too light, your muscles won’t gain much, If the weight is too heavy, you’ll end up injured. But if the weight is just a touch beyond your normal, then your muscles will adapt to the new stimulus and equilibrium will take a small step forward.
Thus, the best way to achieve a new level of equilibrium is not with radical change, but through small wins.
Remember! “if you don’t change anything, nothing’s gonna change”
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