The centre of gravity of an object is the point where the net force is the point at which the force of gravoty can be considered to act on the body. In principle, every part of an object feels its own force of gravitational attraction towards the Earth. The overall effect is as though there were one force acting through the centre of gravity of the body. The centre of gravity of parts of the human body influences the way we walk, run, stand and generally move around. When we do these things, the tendency is for us to minimise the effort we make and the pain we experience. When we walk, muscles in our legs move the legs, and other muscles bend then. The centre of gravity of our body parts is always changing as this happens. The centre of gravity of a pregnant woman is constantly changing throughout the pregnancy.