Biological Tissue is not Inert: the body is not a machine, Volume 1.
An awful lot of lip service is paid to the “your body is not a machine” rhetoric. But do we really fully understand the implications of this statement? Do we fully integrate this understanding into our practice? There is a host of reasons why it is not appropriate to consider or describe the body as a machine. But this is the most significant one in my view:
A machine is made from inert material; living biological tissue is not inert.
Let’s make this simple to start with.
Scenario A: There is a wooden pole holding up my veranda. Twice a week I head outside and take to this pole with a hammer (what can I say, anger issues). Over the course of time, the wear and tear - or microdamage - that I inflict on this pole will have a predictable result. The damage to the material will weaken the structure, and it will eventually break under the weight of the roof.
Scenario B: During the same period, I also do some deadlifts. Twice a week I head to the gym and do my programme. Over the course of time, the wear and tear - or micro-damage - that I inflict on my body will have a predictable result. The damage to my tissues will cause the tissues to adapt and respond to the load, and my body will eventually get stronger from lifting the bar.
Spot the difference between Scenario A and B?
Inert material - such as dead wood or metal - subjected to load, only has the capacity to withstand that load. It does not have the capacity to adapt in response to load. Materials will fall somewhere on a continuum from fragile to robust, and may be quite resistant to damage, but once damaged, it can never repair itself, or adapt to damage. Failure is always a matter of mechanics only.
Living biological tissue, on the other hand, not only has the capacity to withstand load, but also, critically, the ability to adapt and change in response to load. In fact, biological tissue needs mechanical load in order to function, from the cellular level up. This is not a fancy new progressive ideology, either. This is Physiology 101. Strength and Conditioning folks call it Super-compensation.
This distinction between inert and living substances is a vitally important.
In chronic injury states and disease, tissue failure is not a matter of mechanics only, but a matter of maladaptation. It is a process failure as well as a mechanical one.
Yes, there are instances where significant tissue damage results from an acute external force or load - you fall out of the tree, your bones break. Gravity and mass and acceleration and all that. This is not micro-damage. Even for these acute injuries the tissue will heal and/or adapt as per the body’s natural healing process, in the majority of cases. The body responds and adapts. Where the injury does not heal or where pain becomes chronic, the issue is no longer about mechanical damage, but about maladaptation in the system.
Here, the link between tissue damage and pain, in particular, becomes tenuous (I will write a separate article on pain, so I won’t expand on it here).
I will say again: this is a critically important point, and one that must be deeply understood.
Why? Because your understanding will influence your perception and your approach to rehabilitation. If you are a practitioner, your understanding will directly influence not only clinical work, but also the language you use to convey information to your patients/clients. Your language will affect their perception of their body, their dysfunction and their pain. Getting it right is no small responsibility.
When you present a view to your patients/clients which frames the body as something that gets “worn out’ in the same way inert materials get worn out, you convey to them the idea that once the damage is done, it can only get worse. That further loading should be avoided so as to not damage the tissue further. That pain is a direct consequence of the damaged tissue. That it needs to be “fixed” or “cleaned up” with surgery.
Rather than speaking to your patients or clients in terms of “wear and tear”, consider framing information in in terms of adaptation/maladaptation.
A simple example:
If I believe that the pain and dysfunction I am experiencing is purely the result of the “wear and tear” in my knee, my “bad knee” becomes a permanent fixture of my perception of my body. There is nothing you can do about “wear and tear” - it’s just a part of life. The damage is done.
In contrast, if I view the “damage” in my knee as part of a process - I can approach it with a different mindset. How do I help to facilitate a positive adaptation in my tissues? How can I put things in place which will help the rebuilding process after loading - repair, recovery and growth. These are the things like nutrition, sleep, stress management etc. And of course, appropriate movement and loading. As long as you are alive, adaptation is never "done".
Adaptation is a process. So yes, there is such a thing as senescence - the natural slowing of the body’s physical processes with age. The difference between the 20 year old and the 90 year old? Recovery. But really, a significant quantity of the aches and ailments that are routinely attributed to “old age” and “wearing out”, are not the result of ageing at all but rather the result maladaptation from inactivity and bad health. The body’s natural ability to adapt and respond to the environment is nothing short of astounding. We, in general, do not give enough respect to this innate healing ability, nor do we appreciate the value the value of the thing that most helps up to heal: movement. I’m with C.S. Lewis on this one:
“The magic is not in the medicine but in the body. What the doctor does is to stimulate Nature’s functions in the body, or to remove hinderances. In a sense, though we speak of healing a cut, every cut heals itself; no dressing will make skin grow over a cut on a corpse.”