The body is fluid

"The conventional idea can be stated thus: the body is a fixed frame which is activated by the brain so as to bring about movements of its parts. Now this is only part of the picture; the other part is that the body is continuosly activated by sets of impulses, which determine the tone and thus the manner of its behaviour, i.e. the body is fluid"
P.Macdonald, The Alexander Technique as I see it, pg 63

The conventional idea is that the body is formed by several PARTS, the trunk, the head and the limbs. Those parts are articulated by joints, which make movement possible.
There are several aproaches like "Body mapping" (an aproach within the Alexander Technique), "Feldenkrais", etc., which are based on the hypothesis that bad-coordination is a consequence of a faulty sense of the own body, and that through guided experimentation involving simple movements, that sense can be restored.

That is only part of the picture, like Macdonald says. The other part of the picture is that the body is a fluid WHOLE:
Movement is carried out not only through the visible "active parts", but also through a subtle coordinated, silent action of the rest of the body, which provides support for those active parts and overall balance.
For example in walking, the visible "active part" is the advancing foot, while the other foot must simultaneously take over the support of the body's weight.