Chronic Pain: The Physiological Factor

New studies on the nature of chronic pain are teaching us that pain is the product of a complex of physiological, emotional, attitudinal, and social factors.   It is important to keep in mind that pain is not just one or the other of these factors, but a complex of all.  
 
In spite of the danger of continuing the traditional separation of these factors, in the interest of your time, this blog post is going to focus on the physiological nature of pain.  We’ll cover the other factors in future blog posts.  
 
Pain is not processed in the location where you feel it, but in our nervous system.  How many times have you been on the massage table to say, “It hurts here,” only to have the massage therapist find that that’s not really where the problem is?   My left front hip pain is often from a problem with my right back hip, but I’d swear to you that the problem is my front left hip because that’s where it hurts—and I know better! ​

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Why is this?  Part of that may be because of a nerve being irritated in my left hip as a result of my right hip being off-kilter.  
 
But part of it also has to do with how pain is physically processed in the nervous system.   

​Pain responses don’t actually come from damaged tissue, but from the nervous system’s receptors that receive information about what’s going on in our tissues from the nerves.  Nerves move through fascia, the white gooey stuff that serves as the ground substance for and surrounds and divides all parts of the body into muscles, glands, organs, etc.   In fact, the myelin sheath of a nerve is comprised of the same collagen cells as its surrounding fascia.  The nervous system's receptors found throughout the body receive input about what’s going on in our muscles or our organs in order to tell our brains, “Hey, here’s what’s happening here.  Do something!”   

Here you can see the ulnar nerve (+ and white arrow) as it emerges out of and is encapsulated in some deep fascia (black arrow). The white shiny, wet substance is also a type of fascia. The red areas are muscles. The ulnar nerve is a major nerve, unlike most tiny nerve endings which are found in the fascia throughout our bodies.

Our muscles then receive information from the brain about how they should respond—should they tighten up or loosen (that’s pretty much all muscles do)?   If we perceive a threat, our muscles tighten in order to explode into action at full force. If this tightened muscular spring doesn’t get released, our muscles can become chronically tight.  This is why exercise helps us; it releases the wound-up spring in our muscles.  This is also why, when we’re under a lot of stress, the muscles in our shoulders can feel like a concrete block of pain—so much so that they have trouble getting information in from the nervous system to “loosen up already!”   
 
If you’ve had an injury to a muscle, collagen repair to a tear or strain from the nearby fascia leaves the tissue less responsive to input from the nervous system.  Fascia in the area can coagulate to help shore up a stress or weakness in the area, but this normally fluid substance can get stuck, leading scars or adhesions that result in abnormal input from the nervous system.  There may be little or no feeling from the nerves (tingling or numbness), or the fascial thickening could be irritating the nerves to the point of constant pain.  This is when you need the outside intervention of a massage to help you do what you can’t do yourself--relax the muscles.  
 
Even if you don’t have access to a professional massage, you know that just having a loved one rub your shoulders (or wherever you’re tight) can bring you some relief. Part of this is not just physical, but emotional and social as you feel cared for enough to relax.   However, if you have a beef with the family member who’s rubbing your shoulders, you may actually become more tense and sore.  This is because of the other inputs that affect how we process physical input from our tissues’ receptors.  These other inputs include information from our social environments and our own thoughts and emotions processed through memories of past events, which we will talk about in our next blog post.  
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