Pain Science Pt. 1 - What is Pain and how does massage help?

Let’s face it, we’re all going to hurt at some point.
Pain is a mysterious phenomenon that we frankly know fairly little about. It can be sharp, dull, radiating, burning, numbing; it can make us shout, stop our breath, or reflexively punch something. Some pain lasts mere seconds while some can last months if not years. The causes can be obvious, ‘Hey doc, there’s a bone sticking out of my leg’, or it can puzzle healthcare professionals who have exhausted their list of potential diagnoses. When we’re caught in its grip, pain can be extremely distressing; it interrupts our lives, our plans for the future, and our ability to be present with what’s in front of us. The longer we experience it, the more distraught we may become, and the more desperate we can get to alleviate it.

As a massage therapist, my sole purpose is to help people deal with their pain. I am not going to make the claim that my work will magically fix the cause of their issues, but what I can say is that together we can create an environment in which they experience the sensation of their pain with more spaciousness and ease. In order to begin this therapeutic relationship, I think it’s important that we get on the same page of what exactly is happening in our body when we experience pain and what we can do about it.

Pain - The Science
The International Association for the Study of Pain defines pain as, “an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.” The important part of this definition I want to highlight is the idea that pain can be generated by POTENTIAL tissue damage. In many cases of chronic pain, the nervous system can become overly sensitized and generate pain signals even in the absence of tissue damage. This makes diagnosis and treatment of certain pain conditions incredibly tricky.

Pain is broadly categorized into two types based on length of time: acute pain and chronic pain

1. Acute Pain - This is the shooting sensation we experience after stubbing our toe. It’s likely caused by legitimate tissue damage and is a sign of immediate threat to our bodies. Whether it be a cut, infection, rapid change in temperature, or extreme stretch. It may last somewhere between 3-6 months or even less.

2. Chronic or Persistent Pain - This is the trickier of the two in that the causes are much harder to isolate. It’s marked by a longer passage of time (>6 months) and typically seen after the body has healed from some prior injury. This is a huge topic (and an important one for massage) that will be explored in more depth at a future time.

Pain is considered a biopsychosocial experience that goes beyond the organic reality of what’s happening. This means that our perception of pain is colored by our emotions, our culture, our attention, and prior experience. What one person considers a ‘good burn’ after a workout, another could perceive as debilitating. This makes pain a subjective experience, with each case of it being unique to the individual. There are a number of reasons why this is but in order to fully explore them, we have to dial in on the neurology of what’s happening when we get hurt.

The Ascending Pathway
Let us imagine that you had just stubbed your toe on the front step. There you are, hopping on one foot shouting curse words on the porch…it’s fine, nothing new to your neighbors. If we were able to zoom into the chemical processes of your foot, we would see that an immune response has immediately taken place and as a result, has stimulated what are called Nociceptors. These special sensory cells are your body’s primary tool in detecting noxious and potentially threatening stimuli. Cuts, rapid change in temperature, extreme stretch, blunt force, all of these are considered noxious to the body. When they perceive a threat, they send signals from the affected area into the spinal column through a process called nociception. This process brings those signals up your spine through the spinothalamic tract into…you guessed it, the thalamus. (You probably didn’t guess that, sorry for assuming).

* It’s important to note that nociception itself isn’t pain. We actually have a consistent low hum of nociceptive information coming from our bodies at all times. Most of it is dampened in the spinal dorsal horn in a process detailed in the famous ‘Gate Control Theory’ published by Melzack and Wall. We will definitely be covering this in future posts.*

The thalamus is a portion of the limbic brain and is considered the relay center that sends the various incoming information from your spinal cord to the appropriate regions of the brain. In this case, it sends the nociceptive input to a few important and interesting sectors of the brain; the somatosensory cortex, the frontal cortex, and the rest of the limbic system are chiefly among them. With all of these structures operating in tandem, we come to our unique subjective experience of pain.

Let’s take a deeper look at these three core structures and their implications in generating this uncomfortable experience.

1. The somatosensory cortex is a thin slice that runs through the middle of the brain horizontally. It’s charged with the responsibility of integrating sensory and motor information for skilled movement. It’s how we are able to know which part of our body is being touched, hurt, or changing in temperature. When we stubbed our toe, we knew it was our toe and not our hand because of this structure.

2. The frontal cortex is the most anterior portion of the brain and it has the highly important function of using language, problem solving, judgment, impulse control, and knowing social behavior. For simplicity’s sake, this is what most easily contributes to our ability to tell stories and categorize the experiences that we face in life. This allows us to piece together that we stubbed our toe because we were in a rush to start dinner after a long day’s work.

3. The limbic system is the part of our brains that deals with emotions and behaviors, primarily those which deal with our survival. It’s comprises four primary structures - the thalamus, amygdala, hippocampus, and the hypothalamus. This set of structures is most known to motivate us to feed, reproduce, care for our young, and tend to our fight or flight responses. This part of the brain is responsible for the brief moment of panic as pain shot up through our leg.

*This isn’t a complete map of where nociception gets sent but it’s a workable one that will help contextualize how massage may help deal with pain.*

It’s also only half of the picture in regards to how the body senses and responds to pain - what goes up must come down. The ‘Descending Pathway’ will be a conversation for another day, ripe with it’s own juicy implications for massage. What’s important to understand about this now is that each of these brain regions has a unique way of amplifying and sustaining the experience of pain. Strong emotions, fixated storylines, and hyper focused attention can physically exacerbate the perception of pain and extend it for longer periods of time after the injury has healed.

So where does a massage practice fit into this?

Massage is a biopsychosocial experience
The anticipation is mounting as you walk into the massage office; the lights are dim, there’s soft music playing, and your therapist has an inviting presence. (Is that lavender you smell?) You sit down and begin telling them about your chronic neck tension, the shoulder surgery you had five years ago, and the sleepless nights from overthinking. They’re actively listening to you, seeking clarification, and nodding gently. There’s already a subtle sense of relief simply in having someone listen to your pain history as the jitters of meeting someone new starts to fade. They then leave the room, allowing you to undress to your comfort level as you lay down on the table.

For the next sixty to ninety minutes, you’re taken on a journey through your own body. Not only is the therapist addressing your primary concerns but they’re finding spots that you didn’t even know were tense. By the end of the session, your body feels like Jell-o and there’s a strong sensation of having left somewhere and came back. Beyond the cascade of physiological changes occurring in the body (to be talked about in another article), there is a felt sense of emotional wellbeing, social connectivity, and internal homeostasis.

In this time, we’ve addressed the somatosensory cortex by providing new sensory input for the physical body which gives the mind something new to chew on. This acts as a disruptive mechanism for the hyper fixation which usually accompanies and prolongs pain. It allows us to feel a sense of spaciousness where we once only felt tension. We’ve addressed the thalamic system by bringing the nervous system down from it’s emotionally volatile state into one of deep relaxation. This gives us a break from the stress we’ve had from managing our painful condition and helps keep us from catastrophizing. Lastly, we’ve addressed the frontal cortex by introducing new information which demystifies the pain that we feel and helps us be more at home within our bodies. This gives us optimism for engaging with a therapeutic practice and a wider appreciation of our bodies elaborate defense mechanisms.

From this perspective, we come to find that the game isn’t played by bullying upset tissue into submission or breaking apart painful adhesions (This is actually not a scientifically sound approach to massage). What massage provides is a space to introduce new patterns into agitated neural circuitry through deep relaxation, education, and effective/relevant techniques. All of these aspects help us manage our painful conditions and help us prioritize treatment plans that respect our nervous systems rather than provide more noxious input from insensitive therapists. Massage is a holistic response to a holistic issue, it is not a cure-all but it can be a wonderful addition to any wellness regiment or pain management plan.

Check back soon for part two of this series on pain to explore the ‘Descending Pathway’, which is how the brain responds to the perception of pain.

SOURCES
1. Pain Processing in the Human Nervous System: A Selective Review of Nociceptive and Biobehavioral Pathways - Eric L. Garland, Ph.D
2. Mental stress inhibits pain perception and heart rate variability but not a nociceptive withdrawal reflex
3. Pain and how you sense it
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6203285/
5. Why Learning About Pain Science Can Help Heal Chronic Pain
6. Nociceptors - Introduction to Pain