The Principle of Moving with the Center of Gravity
How well do you know gravity? You have an intimate relationship with it, and it is the basis of influence for every movement you can make. All movement is a manipulation of your center of gravity, and how you use that center of gravity determines how in sync you are with the forces that act upon you. Gravity can act against you, and it can drive you forward, all depending on how adept you are at manipulating it, and what kind of habit you maintain in daily life.
The center of gravity (or center of mass) is the point around which all the surrounding parts of your body balance. This can shift as you change positions and even be outside of your body, especially when your center of gravity includes the mass of carrying a heavy object. Moving your head, arms or legs, wearing a backpack, and pretty much anything that moves you out of a static position will alter your center of gravity.
Body weight and body mass are different. Your body weight is relative to the force of gravity, whereas your body mass is the same regardless of the force of gravity. In outer space your body mass would remain the same, but your bodyweight would be, by contrast, less due to the change in gravitational forces compared to being on the earth. Your weight is the force that your body mass exerts when under the influence of gravity; the greater the gravity, the more force your body mass can produce.
The center of gravity lies in the seat of our pelvis. From the front, you can measure its center with the width of your hand below the belly button. From the back you can think of it being in front of the 5 fused sacral bones, at the level of the 2nd fused bone. With the front and back as a reference point, it’s easy to visualize a cantaloupe sized ball of energy sitting in the bowl of your pelvis. This position can change based on what you do with your body.
To stand still you must keep your center of gravity in its natural resting position, or use muscular tension to compensate. The latter habit will eventually result in abnormal tension and pain in the body. To move your body and remain standing in place, you must shift your weight and counterbalance to maintain the position of your center of gravity. In order to begin locomotion, i.e. move from your standing position, you must shift your center of gravity in the direction you want to go. For example, if you want to begin walking, you must shift your center of gravity forward, outside of your body so that you can begin falling forward to catch yourself with the next step.
If you watch a ballerina or a graceful dancer, it’s the control of their center of gravity that gives off this heir of finesse. With an exchange in martial arts, whoever is capable of maintaining control of their center of gravity is less movable and manipulations like grappling aims to manipulate a person’s center of gravity away from their core where they have less control and ability to resist.