On posture

Whenever you find your self tensing in a fixed posture, for example you might bend the torso to wash your hands on a lavatory, and your kinesthetic sense sends you information that you are pulling your head backward. In this situation, you may be tempted to "do" the opposite thing to correct your posture, i.e. your "position", by moving your head forward.

There are a good number of reasons to "inhibit" such response.

"The opposite of wrong is wrong"
Noam Renen, Use your brain

When you attempt to correct your posture by changing your posture, it means that you are reacting according to the conception that "there is such thing as a right position". Moreover, your sensory appreciation of your own posture is wrong, so the outcome cannot possibly be right.

"There is no such thing as a right position, but there is such thing as a right direction" F.M.Alexander, Teaching Aphorisms

In the example above, instead of moving the head forward, the whole back should be "directed" (NOT moved!) backwards, that is the meaning of the information conveyed by the kinsethetic sense.

By such indirect procedure, you may find your knees freeing, flexing, so that you lower the hips, the torso is directed backward and the head ... forward!!

"The movement, if any, is, in an experienced pupil, so small as to be hardly a movement at all"
P.Macdonald, The Alexander Technique as I see it.