Center of Gravity and Base of Support
Balance is a Knife Fight
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Our popular conception of balance is one of harmony, concord, and peace. We associate balance with good things. And it is a good thing. But balance is not peaceful in the sense that it exists in the absence of discord and violence. Balance is the knife's edge of existence between equal and opposite catastrophic forces.
The moon's orbit is in balance. Slow it down a bit and it crashes into the Earth. Speed it up and it hurtles off into space. What looks like stillness from a distance is continuous, precise tension between catastrophic alternatives.
Our bodies are no different. Every position, every movement, every moment of apparent stability is an equal struggle between forces that left unmanaged would tear us apart.
Balance is created and maintained by our muscles providing equal and opposite tension regardless of the position in which we put or find ourselves. The difficulty of achieving balance in a particular position depends on two factors: our Center of Gravity and our Base of Support.
Base of Support (BOS)
Base of Support refers to the area under an object or body that makes contact with the ground.
While standing, your Base of Support is the area between the outer edges of your feet.
While standing on your toes, your Base of Support is the area between the outer edges of your toes and the balls of your feet.
While standing on one foot, your Base of Support is within the outer edges of your single foot.
While doing a push up, your Base of Support is the area between your hands and your feet.
You get the idea.
Center of Gravity (COG)
Center of Gravity is the point where the distribution of weight is equal in all directions. This is also sometimes referred to as Center of Mass.
Technically Center of Gravity and Center of Mass are not the same thing—because weight and mass are not the same thing—but unless I'm feeling particularly pedantic I'm not going to correct someone for conflating the two.
However I will be using “Center of Gravity” here—because if you're located on Earth, you're going to have to deal with gravity.
Balance
Our bodies are wired to always prioritize keeping our Center of Gravity over our Base of Support without our having to think about it.
Typically we call this “Balance.”
That's all balance is. “Balance Training,” if there really is such a thing, could be described as, “practicing keeping my Center of Gravity over my Base of Support.”
Put that way I've just described every possible movement or motion a living creature could perform. I've just described taking a piss. I've just described walking the dog so the dog can take a piss. Both you and dog are “balance training.” I've just described some drunk girl at the club hover squatting over a public toilet trying like hell not to touch the filthy seat.
In all of these situations we're practicing keeping our Center of Gravity over our Base of Support. The drunk girl is challenging her balance the most, so she's probably the only one of us who's consciously aware of the fact that she's balancing.
Who the hell knows what the dog is aware of.
We're balance training all day, every day, and typically we're not aware of it until circumstances present us with a particular challenge to either our COG or our BOS.
When we climb a step ladder, we're raising our Center of Gravity vertically over our Base of Support. In effect we've increased the distance between our COG and BOS. Also our Base of Support has changed from the area between our feet to the area between the legs of the ladder.
As we climb higher we become more and more aware that any lateral shifting of our COG threatens to cause us and the ladder to topple over. The ladder is essentially a neutral lever, and our body weight is the load. The higher we climb, the longer the lever, and the less horizontal force is required to move the load past the Base of Support and send us plummeting to the ground.
Conversely, most of us have probably been told at some point during sports practice or martial arts class to “lower your center of gravity” in order to better perform some movement or execute a task.
By lowering our COG we are shortening the vertical distance between our Center of Gravity and our Base of Support. The decrease in distance requires a greater horizontal force to knock us over—increasing our stability.
Another way to make us aware of our balance is to change the nature of our Base of Support. Imagine walking on the sidewalk and encountering a patch of ice.
Suddenly the friction between our shoes and the sidewalk is gone, and at any time our Base of Support (our feet) could suddenly slip horizontally away from our Center of Gravity. The result is we are forced to take smaller, shorter steps. Or if necessary crawl on all fours—lower our Center of Gravity and increase our Base of Support. Not dignified, but we probably won't break anything.
The same is true for any unstable surface: sand, trampoline, physio ball, balance board.
It's easier to kneel on a paddle board than to stand. Likewise it's easier to boogie board than it is to surf. The difference is the vertical distance between our Center of Gravity and our Base of Support.
Our brains and bodies prioritize balance over all other factors. What this means is that if we have a limited or unstable Base of Support, and/or our Center of Gravity is not over our BOS, the contractile capability of our muscles will be compromised.
In other words our muscles will be weaker. This is a neurological response to a mechanical situation.
Conversely, a greater and more stable Base of Support will mechanically and neurologically increase the contractile capability of our muscles.
Our muscles will be stronger. Stronger muscles allows us to generate more power and provide more of a challenge to the muscles, which in turn builds more strength.
Again, these concepts are fairly intuitive.
How much can you deadlift on a concrete floor?
How far can you hit from a fairway bunker (unstable base of support)?
How clean can you carve a turn when you hit boilerplate (unstable BOS and COG not over BOS)?
Our conscious intention is to execute a specific task, and our unconscious, automatic nervous system will do what it does to enable that to happen to the best of its ability.
But if our mechanical situation is in question—if our Center of Gravity is in danger of not being over our Base of Support—our unconscious, automatic nervous system will override whatever goals or intentions our idiot conscious brain sets out to accomplish.
Not falling on our ass and breaking ourselves is more of a priority than hitting some abstract personal record—at least as far as our automatic nervous system is concerned.
Our conscious brains may disagree, but our conscious brains only get to be in charge so long as our unconscious brains allow it.
In the next article I'll go through a handful of discipline-specific scenarios to flesh out these concepts more fully.
