Let me preface this section by saying I am not a doctor and have no formal training in physiology. That said I have always been fascinated by the incredibly complex machine that is the human body. If any doctor wants to call me out, please do so. I've tried to get as close as a musician can on the topic.
I've always been really taken by dancers. They seem to have such total control over their bodies that they defy gravity. If we could go inside the brain of a dancer though we'd see that the illusions they create are really a whole series of very finely tuned biological systems all working together. As I said I am not really an expert so I hopped on the old interweb to do a little research. I found that equilibrioception is the fancy medical term for the physical sense of balance. As I suspected it is the result of a number of body systems working together: the eyes (visual system), ears (vestibular system) and the body's sense of where it is in space (proprioception). According to Wikipedia (a reputable source) "The balance system works with the visual and skeletal systems (the muscles and joints and their sensors) to maintain orientation or balance. Visual signals sent to the brain about the body's position in relation to its surroundings are processed by the brain and compared to information from the vestibular, visual and skeletal systems."
There are couple things that strike me about this. First, as I suspected there are lots of things going on at once making balance possible. Second, and possibly more important, is the fact that balance is the brain's attempt at dealing with chaos. The definition of chaos I am thinking of is maybe the slightly more 'scientific' definition which is a seemingly random series of events. Beautifully chaotic. Your brain is having to take in a fantastic amount of ever-changing information and make the proper adjustments while sending and receiving information from the eyes, the inner ear, the nerves, and the muscles. Truly amazing.
The removal of the brain tumor was the first time I had to really deal with physical balance but all of us have had a time when not all the systems were working together such as an ear infection or an over indulgence in adult beverages. The tumor I had was called an Acoustic Neuroma or Vestibular Schwannoma. Fortunately the tumor was benign but unfortunately it was very large (the size of a lemon)and putting pressure on my brain stem so emergency surgery was required. As you might be able to guess from the name the tumor is caused by an overgrowth of the Schwann cells that make up the myelin sheath that cover each nerve in our body. Schwann cells occur specifically in the peripheral nervous system. Think of it as the insulation on a wire. In this case the overgrowth of cells happens on the vestibular nerve. I will go into more detail later but what is important here is the surgery resulted in the removal of one of my vestibular nerves. I lost hearing in my ear but more importantly I lost one of the nerves that sends the brain information about the body's position in space.
What is truly fascinating about the human brain is how it can adapt to situations like this by using other systems to compensate. Let that sink in for a second. I'm not going to lie. It was not an instantaneous process. When I was first recovering from surgery I couldn't even sit in a chair without getting extreme vertigo and nausea. Over the coming weeks and months though I eventually went from sitting to standing to walking short distances to climbing stairs to walking around the block and so on until I was back to at least a new normal. In all of this the brain was rerouting connections and I was learning what I had to do physically to compensate for my new-found balance issue.
I'd like to focus on three points from the last paragraph. One, the idea that it took time for hindbrain to learn to aid the system that needed help. This is an unconscious function. Two, I learned the conscious adjustments I had to make. Three, the concept of a new normal.
To me the concept of a "new normal" is one of the harder but more valuable lessons I learned from the ordeal. The definition of what balance is from moment to moment is fluid. As fluid as the process itself. I think it can be hard for us to get next to idea that something is not going to be the same every time we come to it. There is comfort in sameness. Things that we can rely on. But we can also come to take these very same things for granted. Call it complacency or apathy. It takes real effort to try to conceive of the fact that there are actually millions of things zinging around in every moment making that physical balance possible.
The other lesson here for me was putting trust in systems that I couldn't control and exerting control over that systems that I could. Also recognizing what gaps needs to be filled and learning what I could do, or not, to fill them.
Thinking about more philosophical or metaphysical topics by comparing them to physical phenomenon can sometimes help to illustrate the concept. For that reason I outlined my views on physical balance first. For me any kind of balance requires multiple systems working together and an understanding that the definition of balance is as fluid as the process itself.