Centre of Gravity
The Centre of Gravity is an imaginary point about which your body
balances. The position of the 'centre of gravity' is roughly around the 5th
lumbar vertebrae (in line with the belly button). Generally the 'centre of
gravity' in men is higher than in women. As you perform different gymnastic
movements, your body shape is constantly changing, and this affects the
position of your 'centre of gravity' (see the picture above - below for more
examples).
Balance is lost when your centre of gravity moves outside your 'base'.
Stillness
To gain a balance some degree of speed is needed, but as you reach the
point of 'balance', this speed should be slowed down until you achieve
stillness.
To keep stillness your centre of gravity must be above your base.
Changing the head position
Changing the head position can
affect the position of the centre of
gravitiy. The picture shows a man
standing on one leg. The man on
the left is off balance because the
centre of gravity is out with the
base. The man on the right has
moved his head to the side, which
moves the centre of gravity over
the base and makes him balanced.
Changing Limb Position
The picture on the left shows
roughly where the centre of gravity
is during a headstand. By altering
the position of limbs the centre of
gravity changes, as shown on the
righthand picture. If you look
closely at the hip position of the
right picture you can see her hips
are further back to make sure the
centre of gravity is still over the
base.
Stable and Unstable Positions
The person on the left is in a less
stable for 2 reasons
.
Reason 1
The man on the left has a narrow a
base (shown by the yellow line),
whereas the one on the right has a
wide base. Having a wide base
makes you more stable and less
easy to push over.
Reason 2
The Sumo Wrestler has a lower
centre of gravity (showen by the
yellow dot and green line). When
the centre of gravity is low it is
harder to push over.
A good example of this would be a
traffic cone...
The cone the correct way up is
stable and difficult to knock over,
when it is up-side down it is less
stable due to the narrow base and
the heavy end higher up.
Centre of Gravity – Extension
The centre of gravity does not
always have to be on part of the
body or object. In the picture of the
girl in a bridge position, the dot
shows where the centre of gravity
is in this position