Personally, I understand posture as the dynamic balance of the parts of the body in space in relation to the force of gravity at any given moment and for any given position. In other words, posture at any given moment marks an equilibrium. This latter exists by virtue of the necessity with which the organism is faced with moving its body masses and adapting to the pull of the earth which can be regarded as a constant. (Dynamic Process Integration, Ida P. Rolf, 1954)