MOOCS Entendendo Dor Crônica para Viver Melhor - 07 - O medo e a dor

Hello, in today's lesson we will talk about how fear can contribute to the perpetuation of musculoskeletal pain. Our goal today is to understand how aspects related to fear can contribute to the perpetuation of pain, that is, taking longer than usual to heal the pain. Before we start talking about this topic, of fear and pain, I have here a work of art made by Michael Alfano, called swept by the wind.

And this piece, I wanted to propose a reflection before we start, I think we all have felt some kind of pain, but some people feel pain everyday, and they, oftentimes, feel exhausted, constrained and see no perspective of improving, as if they had been swept by the wind. We need to understand human emotions in order to also understand how people cope with their pain. So, I'm going to share some theoretical models to try to explain how fear can influence the perpetuation of pain.

A very interesting experiment carried out by Watson and Rainer in 1920, and it's called the Little Albert experiment. This experiment was the first one to reveal that fundamental emotions, such as fear, anger and love can't be learned, but can be conditioned to other stimuli or attached to other stimuli. How did this experiment work?

I want to make it clear here that, nowadays, the Ethics Committee would probably not approve a study like this one, but it was very needed at the time, because it was the first demonstration of classic conditioning in the field of human fear and it also provided evidences of the generalization of conditioned fear. I'll explain a bit about how the Little Albert experiment worked. Watson placed baby Albert on a mattress and showed him a furry little animal, such as a rat.

Every time he placed the rat on the baby's lap, he made a very loud sound that would hurt the baby’s ears, and he repeated this many times and, over time, baby Albert was conditioned to being afraid of feeling pain. Months later, baby Albert, then, didn't even need to listen to the sound to cry, if the furry little animal was close to him, he would already start to cry in fear of feeling pain. Something interesting about this experiment is that when Watson placed any other furry little animal close to baby Albert, such as a rabbit, for example, baby Albert would start to cry in fear of feeling pain.

This indicates a generalization of fear. Why is it important for us to understand that? Our brains use prediction mechanisms to avoid encountering threats or to find a way out of dangerous situations, and the fear of experiencing pain leads us to avoid such situations.

Another very famous experiment in literature is the Pavlovian conditioning. It also explains a bit about how the brain creates prediction mechanisms to protect the body from threats. The Pavlovian conditioning works as the following: there is a dog and, first, they give the dog food and it starts salivating, after that, every time the dog is fed, they ring a bell, and they repeat this several times.

Over time, on the long run, they didn't even need to bring out the food, the dog would start salivating solely by hearing the bell ring, meaning that, for animals and human beings, emotions are unconsciously associated, and these are predictive events. Defensive activation is found in three response systems of the body. The first one is psychophysiological alterations, such as increased muscle tension.

I'm going to give an example: a patient has lumbar pain and tells me they can't lean forward because they fear feeling pain. When I show them a video of someone else doing this same movement, they don't even need to do it, they already feel more muscle tension because he feels afraid of even looking at the movement that causes him pain. Other mechanisms are the behavioral mechanisms of flight and avoidance.

Individuals who fear feeling pain often experience avoidance behaviors and they start to avoid performing movements that may cause them pain. Aside avoidance, they dodge activities, obligations and situations that may expose them to that painful movement. There are also cognitive alterations, such as catastrophizing and verbal reports of fear.

A patient comes to us and says: "I can't raise my arm above my head", but they specifically say they can't move like that because they fear pain. There is also catastrophizing thinking. The patient believes that their situation won't improve, that their situation is more extreme than that of others, and they end up feeling very frustrated with the lack of perspectives to get better.

Pain-related fear is a broad term that encompasses several situations in which a patient may feel threatened. It's like a threat to a possible painful condition. So, there is the effective fear of pain, the patient doesn't even move because they're scared of feeling pain; the fear of reinjury, they don't move because they feel that, if they do, they may get hurt, have the same injury again; the fear of movement itself, so they specify "I can't lean forward", "I can't tilt my head to the side", because they think these specific movements will cause them pain; the fear of performing certain activities; the fear of activities related to work, the patient believes that working worsens their condition, so they are scared of going back to work and feeling pain; the fear of visceral sensations, a patient that, for example, felt a very strong kidney pain, had urinary infection or some kidney pathology and felt so much pain in that moment that, if they feel pain close to that region, they become terrified, they are scared of feeling such visceral reaction again; and the fear of touch, some patients are fearful of contact with their skin.

Now I will share a model, it's called the fear-avoidance model of pain, and I translated this diagram, I will explain to you, then, how the brain interprets pain, through our experiences. This model displays two paths: one path has the perpetuation of pain and disability and the other path has complete recovery after injury. After an injury, as observed here in the diagram, the patient goes through the pain experience.

And if this experience is linked to negative affectivity, to negative emotions, to the fear of pain, it will lead to catastrophizing behavior, the patient will think they won't recover, that their condition is too severe, and they will start to connect this pain experience to the fear of being in more pain again. They avoid moving, constantly monitoring their movements, they also avoid doing certain activities and fall into disuse Disuse leads them to feel incapable, triggering sadness and depression and increasing the experience of pain. Notice, then, that this is a cycle, the more pain one experiences, the more they experience fear, disuse and disability.

So, it's a cycle of fear and pain perpetuation. On the other hand, when a patient has an injury and experiences pain and this experience is not connected to fear, but, surely, by coping with the situation, the patient ends up recovering. To conclude this model of how the brain interprets our pain experiences, when there is a potential lesion in one hand, it can be experienced with fear or, on the other hand, without fear.

So, through our learning process here, we already know that pain is like an internal alarm, it protects and alerts us that our bodies are in some danger. So, predictive learning serves this cause, but what is concerning is that predictive learning can influence pain perpetuation for a longer period than usually needed to heal. So, situations such as generalization and avoidance lead to disability and more pain.

Nowadays, for example, we know that when a patient is scared to move we should not regarding fear itself, but regarding avoidance, telling them they shouldn't avoid activities or apply their generalised fear to other things. So, we should strongly stimulate our patients to not avoid moving, stimulating them to stay active. Now with this image, I’ll give an example of generalization and avoidance of movement.

A patient may fear leaning their torso forward because it hurts, but, as you can see below, they don't feel pain when extending their torso or leaning it back. What predictive learning of fear does to a patient is not only avoiding to lean forward, but also not leaning back anymore and the result of such limitation is disability. And, in order to stop pain-related fear, we should encourage patients through safe approaches, gradually exposing them to more movement every day.

But the most important aspect, which I want to register here, is that pain-related fear can be resignified and new habits can be learned. So, I share here a picture of a sculpture made by Michael Alfano, called Handmade. And, also, a quote that says "We contain our own future".

What does this mean? Within us, we have strategies, tools to give new meanings to fear of pain, and to win the battle against pain. We can believe that we have the conditions needed to find solutions inside ourselves.

And my role here is to help you understand this and resignify your pain, simply increasing your knowledge of this whole process, as well as demystifying any situations you may think are detrimental to your pain. Resignifying through your knowledge and by acquiring new habits. I would like to say that I'm very happy you made it here with me.

Keep on learning, until the next lesson! [Thank you for watching until now! Keep on learning!