In the next few posts I'd like to focus on some of the practical principles involved in maintaining balance while skateboarding. Though I'm relating these principles chiefly to skateboarding, they can be applied to physical activities in general.
1. The 'centre of gravity':
Every object has a point where its entire weight is concentrated; where the weight of the object may be said to act. When dropped, an object will fall toward this point. In a rigid object of homogeneous mass, the centre of gravity is at the geometric centre. But in an object of irregular mass, the centre of gravity will be where the object is weightier, and not at its geometric centre. Obviously, the human body is of irregular mass, that is, each body part has a different composition and weight. Its centre of gravity is thus not at its geometric centre. So where is it? When a person stands upright, his centre of gravity is located near the navel.
However, the human body has an added complexity. It is not rigid and fixed, but keeps changing shape as a person wills himself to move. As a result, its centre of gravity constantly changes location. It will shift when a person raises his arms, and all the more so when he bends over to touch his toes or dives forward off a diving board.
Adept sportspeople learn how to shift their centre of gravity in order to move in a desired manner. This learning process may be conscious or subconscious. Hence, when a sprinter is at the starting block, he'll lean forward so that the centre of gravity is such that it is easy for him to take off, propel himself forward, and begin sprinting with minimal effort and delay. The long jumper learns to mentally project his centre of gravity toward his desired jumping goal, so when he jumps, his body takes on the form that brings his centre of gravity in alignment with his projection point. This allows him to move in the desired direction more effectively.
In skateboarding, every trick requires such a projection. One must imagine where the board is going to move when performing a trick so he can project his centre of gravity in that direction, move with, and subsequently land on the board. Learning this principle has bolstered my skating ability immensely. I discovered that much of my failure to land tricks was due to two things:
a. incorrect trajectory or projection point of the board. Or, more simply, a misjudgement as to where my board would move when flipped or rotated in a certain way;.
b. an inability to project my centre of gravity effectively in the direction of the board's movement.
Having learnt this principle however, I started to keep focus on ascertaining the direction and distance the board would move from its original place - gauged largely through practice - and then concentrated on projecting my centre of gravity toward that spot so that I was more likely to be above the board upon landing.
'Base of support'