Over the past few years increasing numbers in chronic pain patients are being seen in the outpatient clinics. As a therapist pain is something that is discussed daily with all patients. However, everyone has a different perception of what pain is, how to describe their pain, and how to cope with their pain. Pain can be explained from the scientific, emotional, and personal perspective. Science shows that chronic musculoskeletal pain is stemmed from an alteration in the central nervous system processing.
So, lets explain pain from the scientific perspective. The body goes through a physical change or injury sending an input from your central neurons to the central nervous system, thus altering how the brain processes the information provided. Science shows with pain there is increased activity in the brain to the pain sensation centers, such as the prefrontal cortex where decision-making and problem solving are linked. Without new input to the body the central nervous systems will remain in a state of sensitization not allowing the pain to resolve. Chronic pain is defined as pain that persists beyond 12 weeks. As the pain persists beyond this time, pain tolerance begins to decrease, compensatory strategies arise, decreased coping strategies are present, and ultimately the pain becomes threatening to the individual’s quality of life. This perception of pain limits the individual’s confidence and ability to move, leading to altered performance and quality of movement patterns. As I stated above there needs to be new input to the central nervous symptoms to change the pain, for example, non-threatening movement.
In science we call this input or lack of input the Gate Control theory. The gate control theory states that non-painful input or no input causes the gate to close to painful stimulus. There is either a stimulation of large fibers (touch- sensation) or stimulation of a noxious small fibers (pain). Small fibers (pain) inactivate the inhibitory neurons thus sending pain signals to the brain from the periphery. Large (touch) fibers excite the inhibitory neurons which diminishes the pain transmission. This explains why when you bump your knee on the corner of your desk, you initially react by rubbing the knee. The rubbing of the knee increases the normal sensory input from the periphery (outside of the spine i.e. our limbs) to the Central nervous system (spine), decreasing pain fibers, therefore decreasing your perception pain. This explains why manual therapies such as massage, joint mobilization, modalities have a direct relation to our sensation of pain. The manual therapy does this by increasing the large fiber activity and inhibits pain transmission to the brain. This explains the transmission of pain, but what about what we see and feel?
Now, let’s explain this from an injury or impairment standpoint. Pain can often be stemming from a real structural and physiological disorder. However, “the diagnosis” or “MRI” does not need to define you, limit your quality of movement, dictate how you enjoy your time with your grandchildren, or the choice to go for that long Sunday run. Prolonged pain starts to send an individual through a downward spiral, trapped inside the inflammatory cycle. Over time it becomes increasingly challenging to break the cycle as our body has an innate way of compensating and mal-adapting for normal loses. Have you ever had an initial small injury to the knee, for example that first snowfall where your forced to shovel your driveway for an hour? You follow standard protocol “RICE” (rest, ice, compression, elevation), but then you continue to have some nagging pain? Even if it doesn’t stop you from your daily activities, there is a little voice in your head reminding you of that initial injury causing a fear avoidance. So, naturally you avoid bending to lift boxes, you park closer to the store, or even worse you don’t plan that golf trip you wanted to go on. So, what do we do? Typically, the fear avoidance of pain starts small preventing certain movement patterns, but over time you notice increasing daily limitations. There is now dysfunction in the musculoskeletal system and central sensitization centers. Ok, so maybe you sustained a more traumatic acute injury initially? You are in a car accident and sustain whiplash and you start noticing pain shooting into your left arm. Following the injury, you go through the normal course of medical management and you get an MRI showing a mild-moderate disc herniation at the Cervical Spine levels C5-C6. Automatically an individual would think they are doomed to surgery or injection and further accelerate the theory you “shouldn’t” move the neck in hopes to not aggravate the bulge or worse get another one. Does this sound like you? Combined medical management and physical therapy can restore movement and decrease pressure on that nerve root versus remaining controlled by the impairments or diagnosis. Now it is 20 years later, and you may have tried some interventions or even surgeries and its better, but it has never fully resolved. The pain perception to that area remains a limiting life factor.
How does all of this explain the feelings and sensation you are feeling? The limbic system is the center where emotions are stored and the amount of pain you feel is modulated. The frontal lobe in the brain is responsible for containing the motor cortex, or center for control of movement of muscles, as well as the prefrontal cortex, or center for personality and clinical reasoning. There have been studies that show that someone who receives a frontal lobectomy (removal of this part of the brain), no longer identifies pain even if is there. Research then shows that pain is merely just a signal until it reaches the portion of the brain responsible for emotion (frontal lobe), and then we perceive the pain we feel. When you think of it this way thankfully we feel pain because this gives us the opportunity to address it. The question is how do we stop the chronic pain and the perception we feel of our pain?
From the initial onset of the pain our body goes into the “fight or flight” mode from the sympathetic nervous symptoms which decreases our immune response and increase to stress. The adrenal cortex mediates stress and release of cortisol when immune system is suppressed, or injury is sustained to an inflamed tissue. Cortisol increases inflammation, decreases tissue recovery, and increases sensitivity to pain. Pain then leads to fear avoidance thus leading to decreased ability to partake in the things you enjoy, and then increasing stress and frustration.
What is a physical therapist and how can we assist with this? A physical therapist treats impairments through movement, exercise, and manual therapies to assist individual pain and function. As a therapist our goal is to see you at the pain point or initial onset. Our hope is to keep you from spinning around the wheel of pain, anger, and chronic inflammatory state. We want to educate individuals on why they are having pain from a biomechanical or musculoskeletal point and then revert the pain through guided purposeful movement. Once we start moving in pain free ranges we give the Central Nervous System (CNS) a good new input and alter the processing of that system that is inhibiting healing. Thus, in the end modulating the pain at the brain and at the musculoskeletal junction. Once the pain is eliminated the goal is to optimize YOUR normal movement and help you return to the activities you love.
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