This article is Part One of a two-part series. Click here to read Part Two.
As children, we would sometimes fall and scrape our knee. Maybe it was bleeding; certainly it was painful. We thought the pain was caused by something at the site of the injury and it was sending a signal to our brain, saying, “THIS HURTS!” Our parents would give us a kiss, put a bandaid over our injury to soothe our pain. Again, we thought if we could cover the wound and heal the tissue we’d be in less pain. As it turns out, this entire concept of the pain experience was not wrong, but incomplete.
There are a number of myths about how we experience pain and why getting rid of it is often more complicated than simply healing our tissues. We will discuss three important myths and offer a more complete truth about the pain experience.
Myth #1 – Pain signals in your body send messages to your brain telling you when to hurt.
Truth #1 – The brain interprets messages from your body and decides how much pain, if any, you will experience. Thus, ALL pain originates in the brain.
A person wakes in the morning with excruciating pain in his right foot. Except, he doesn’t have a right foot; it was amputated 6 months ago. The pain is real. So, how is this possible?
Throughout our body, we have signal receptors called nociceptors, which have, in the past been deemed “pain receptors.” More accurately, they are “danger receptors.” When something happens at the tissue level – sprain, strain, bruise, break, puncture, pinch – these nociceptors initiate a signal to our central nervous system comprised of the spinal cord and brain. It is then up to our central nervous system to interpret that signal. That interpretation has many factors (more on this later). If the signal is deemed sufficiently dangerous, the brain will create a pain response.
That response is sent to a genetically predetermined map in our brain that creates pain in our body. Sometimes, this pain signal is sharp and localized, other times it can be diffuse and dull.
This map exists in your brain no matter what happens in your body. This is why someone with an amputation can feel pain in a body part they no longer have – their brain is creating a pain sensation, even without input from the body. It’s also why some signs of a heart attack are pain in the jaw and down the arm. And why sometimes back pain can feel sharp and localized and other times like your whole back is on fire.
Myth #2 – Pain is dependent only on the amount of tissue injured.
Truth #2 – Many factors play a role in your pain experience including your environment and stress levels.
Imagine two women in their mid 30’s sitting next to each other at the PT clinic. They’re both generally healthy and active. Both have been experiencing neck pain for 3 weeks. MRI and x-ray imaging look identical. Anatomically speaking their injuries are the same, but one woman is experiencing significantly more pain than the other.
In order to find out why there’s a discrepancy with seemingly the same injury, we have to delve deeper. Pain is multifactorial and does not depend solely on the state of the tissues.
What if you knew that one of the women, the one in more pain, was going through a divorce? Or maybe she’s a swimmer and is nervous she may not be able to get in the water again. Perhaps she’s been fighting this injury for 3 years and hasn’t yet found a physical therapist she’s connected with.
What would change if that woman had a terrific social support system of close friends and family? Perhaps her pain would be different if her physical therapist listened to her whole story, understood what swimming meant to her, and made it their objective for the patient to achieve her goal.
Injury at the tissue obviously plays a major role in the pain experience. However, it does not tell the whole story. Stress, anxiety, fear of future pain, social support system, happiness with career, nutrition, and numerous other factors play unique roles. The brain will interpret all of these factors and either up or down regulate the severity of pain.
Myth #3 – There must be an injury in order for there to be pain.
Truth #3 – Pain is a signal of potential danger, rather than past injury.
This may be the most crucial aspect to understanding how pain works. Pain is not a result of tissue injury; it is a conscious alarm your brain sounds to beware of potential future danger.
Lorimer Moseley, a pain scientist credited with much of the research in this field, shared a story in what is now a famous TED talk (https://ed.ted.com/on/Li50Ci7S). Moseley was walking in the desert and gets bitten by a snake. Thinking his leg was simply scraped by a tree branch, he keeps going, feeling no pain. He returns to town, ends up in the hospital and barely survives. Sometime later, he goes back on the same walk. This time, his leg does get scraped by a tree branch. Thinking it’s another snake bite, he is in agonizing pain.
Why the dichotomy? The pain experience Moseley describes in the latter case, shows that the brain remembered the life threatening experience of the snake bite and interpreted a skin scraping as a more dangerous and therefore, more painful.
Evolutionarily, the pain experience is no different than other biological protective mechanisms. Like the turtle’s shell or the rose’s thorn, pain helps protect us from threats. This process translates past experience into current pain in order to protect us from future danger.
In more specific terms, when your brain interprets signals as a credible threat, it will increase pain levels. On the other hand, if it determines that you are in a safe and protected environment, it will reduce pain.
The pain you’re experiencing is very much real. Our understanding of how it comes about has shifted in recent years. Knowing that the cause of pain is more multifactorial allows the treatment to be more holistic, giving physical therapists and patients endless options to assist in its relief.
Louw, A., Diener, I., Butler, D. and Puentedura, E. (2011). The Effect of Neuroscience Education on Pain, Disability, Anxiety, and Stress in Chronic Musculoskeletal Pain. Archives of Physical Medicine and Rehabilitation, 92(12), pp.2041-2056.
Louw, A., Farrell, K., Landers, M., Barclay, M., Goodman, E., Gillund, J., McCaffrey, S. and Timmerman, L. (2016). The effect of manual therapy and neuroplasticity education on chronic low back pain: a randomized clinical trial. Journal of Manual & Manipulative Therapy, 25(5), pp.227-234.
Moseley, G. (2007). Reconceptualising pain according to modern pain science. Physical Therapy Reviews, 12(3), pp.169-178.
About the Author
Ari is originally from Austin, TX. He received an undergraduate degree in Economics and Political Science from UC Santa Cruz, and a Master’s degree in Public Policy from University of Texas. After years of working in the public policy sector in Washington, DC and Austin, TX, Ari decided to make a professional change, return to school and received his Doctorate of Physical Therapy from Texas State University.
Ari believes that movement is a fundamental human right and derives great joy from guiding clients towards achieving their goals. From getting on the ground to play with your grandchildren to preparing for your next marathon and everything in between, Ari wants to help you get there with a smile on your face.