Pain is a complex thing. We've all experienced it and we do our best to avoid it or to make it stop. What can sometimes appear for a brief moment can often become persistent if not linger for longer periods of time. So, what is pain and how does it work? In this week's #physiotalk I'm going to walk you through a hypothetical situation that I'm sure you're all quite familiar with.
The Nutcracker season has begun and Melissa has already been rehearsing for many weeks now. It is her first season with the company and her parents are even flying in to see her first professional debut. There is definitely pressure to give her all and to perform well-- and then it happens in one of her rehearsals. Melissa has been feeling even more stressed lately leading up to this particular rehearsal as her boss (director) would be watching. Though she powers through the rehearsal her body grows tired with exhaustion and as she steps into an arabesque at that moment she feels a sharp pain-like pinch in her lower back. She stops immediately after and a wave of panic takes over her body. Her breathing pattern changes, her pulse begins to rise, and a cold runs down her back where her muscles grow tense after she stops the movement. Melissa has never experienced this pain before and though the sharp pain disappeared after stepping out of the arabesque, there's still a weird feeling that runs from her lower back to the left side of her buttock.
What happened to Melissa?
In order to understand pain, we have to first understand what is happening in the nervous system and everything that encompasses it as it will affect and influence the pain experience and intensity. There are also many other factors to consider such as emotions, the cognitive system, hormones, cardiovascular, and immune system which all play a vital role in how pain is and will be experienced.
Using this concept, let's imagine an empty glass that represents our pain threshold. The glass gets filled by those different influences (emotions, hormones, etc) the nervous system and we only recognize danger when the water in the glass overflows-- that is when our brain reacts with the protective answer of pain. So if we combine stress with poor sleep and nutrition, it all contributes to more water being poured into the glass-- that along with tissue issues can result in an overflowing glass of water which will trigger the brain's protective response and thus we experience pain in our body. All in all, pain is your body's normal response triggered by the brain when it recognizes a threat.
For example, we find this a lot in MRI scans especially in our 30s, almost every third person has a bulged disc or protrusion but experiences no symptom of back pain. In this case, the glass is already filled with water but not enough that it spills over or overflows. When other factors such as stress trigger our nervous system, more water is poured into that same glass and it might be that it does spill over-- this is when one would experience back pain. Similar to the concept of the flu, some people experience stiff joints or already healed old injuries that start to hurt/ache again. This is due to the immune system being triggered which relates to more water being poured into the glass for it to overflow.
As a result of Melissa stressing about the upcoming Nutcracker performances, her cortisol level (stress hormones) was already high for weeks. With all this pressure she was putting on herself, Melissa was also pushing herself to the limit both emotionally and physically-- not resting enough to have a healthy balance.
At the time Melissa did her arabesque, her muscles were already tired, affecting her motor control and the coordination of the arabesque. Here, she used a slightly different movement pattern to compensate and which, in turn, caused a very high, sudden load on her lower back, pelvis, and hip-- stressing one of her facet joints in particular. The sudden load on her back triggered some very fast conducting nerve fibers-- the ones that pass information to the brain and which inform the brain that something has happened and the movement is simultaneously being stopped in her spinal cord. The force of the movement was so intense that it triggered the nerve endings aka nociceptors to react. They are passing on information slowly compared to other nerve fibers like the mechanic/movement informing fibers. What they do is that they register potential danger by watching over our chemical, temperature, and mechanical state, and then they pass the information onto the spinal cord (another neutral nociceptive system) where it will be passed onto the brain if the impulse is strong enough. Ever wonder why it takes so long to tell whether the water is hot or cold under a tap or a hot plate? This is why.
In Melissa's case, her glass was almost filled to the top and it continued to get filled with more water with the added stress of her director watching, her family flying to watch her perform, and her debut as a professional dancer in The Nutcracker. Melissa had pushed her body and cardiovascular system to the max. That and her late-night Netflix binge-watching sessions also didn't help as it ate up the hours she actually needed to sleep-- which all contributed to more water being poured into the glass (instead of out had she rested). The sudden and different movement of the arabesque put a lot of force on her facet joint which was essentially the last drop of water in the glass needed to make it overflow and spill-- which triggered her brain to recognize the danger in her back region.
As the full glass of water sensitized her lower back, the impact was strong enough to get passed on from the neutral spinal cord to the brain which evaluated the situation with first response in the form of sharp pain and then as a dull continued pain. In short, the brain consults the body, factoring in Melissa's emotions and feelings, taking into account previous experiences (any former injuries or pain experiences) which she's had in the same lower back area.
The brain puts all this information together and into context, interpreting her expectations, her thoughts and what is happening in her body at that one moment as she steps into the arabesque. The brain along with our inner emotions decide how we feel in each moment and ultimately determines whether or not we will experience pain in any given moment of movement. Pain is always triggered by the brain and though it is an illusion created by the brain, it is also very real at the same time. If you have pain, you have pain. Think of it as a mosaic piece of art, comprised of many different elements.
Next time we'll dive deeper into the body's response to pain and how Melissa was able to perform in The Nutcracker.
Top image by Paulio Sóvári