The Alexander Technique is all about posture. By adjusting posture a whole new way of being can result. We all have physical tendencies which generally go unnoticed, such as tilting our head towards the fork as we eat, yet our head requires far more energy to move back and fourth that the energy required to lift that fork just a few inches closer to our mouths.

Perhaps it is better described as a  means of integrating one's mental and physical being into one.  It is a practice for maintaining the alignment of  head, neck, and back, which if practiced can lead to optimum overall physical functioning.

Frederick Matthias Alexander (1869-1955), developed the method at the turn of the century.  Although his original purpose was to assist voice projection, Alexander concluded that faulty posture was responsible for a diverse range of problems. 

He believed that habitual unbalanced movement affects the functioning of the entire body, implying that postures entail behavioral patterns and that bad posture distorts the personality.

Alexander also believed that all proper bodily movements flowed from one basic movement, the maximum lengthening of the spine, which he termed the "primary control".