ALEXANDER TECHNIQUE IN PREGNANCY AND CHILDBIRTH: PRIMARY CONTROL OR HEAD/NECK/BACK RELATIONSHIP
The 'use' of himself that Alexander realized was causing a poor functioning was the way he over-contracted his neck muscles and pulled his head backwards and downwards into his shoulders. This had the effect of compressing his spine, causing a shortening and narrowing of the whole of the torso, and stiffening of all the muscles throughout his body. When he shortened his stature in this way his voice became hoarse.
He found that when he was able to prevent himself from stiffening his neck and pulling his head back and down, and allowed his head to go in a forwards and upwards direction in relation to the spine, this released the compression of the spine. As a result, his torso lengthened and widened and furthermore there was a lessening of muscular tension throughout his whole body. With this lengthening of his stature his voice improved.
From these observations, Alexander realized that it was the relationship between the parts of the central axis of the body, that is, between the head and the neck, and the head and neck in relation to the rest of the back, which determined his overall use and functioning. This led him to the discovery that the head, neck and back relationship constituted an inbuilt mechanism for organizing or controlling upright posture, movement and co-ordination throughout the whole body. Alexander called this the 'primary control', and according to him it is the key to developing our awareness and good use in all our activities.
When people first have Alexander lessons they often try to put their head in a certain position, and ask their teacher if 'this is "it"'. Unfortunately for us, the primary control is not a static position of the head on the spine, a 'magic' position to be found and then held, but rather when the head is poised and freely movable, the spine is well aligned and is working as a smoothly functioning whole. The primary control is basically a dynamic relationship between the head, neck and back, an attitude, if you like, and the only definite way of understanding it is to have an Alexander teacher show you what it is and then experience the postural changes that come about.

With this dynamic relationship of the head neck and back, the head is free to initiate movement. All vertebrates (this includes us!) are designed so that it is the movement of the head that leads the movement of the rest of the body. You can see this mechanism working superbly when a cat spots its prey. It is very clearly the head that goes first and the spine follows, and its four limbs move the body in the direction the head is dictating. This is harder to appreciate in human beings where we have effectively come up on to our hind legs and have two directions to deal with - our spines go upwards while we move forwards. However, we still work best, like other animals, when the head is leading and the spine is following - and this is what occurs when we have a good head/neck/back relationship.
We can see the primary control working well in happy healthy children, animals, people in so-called 'primitive' cultures and some athletes. There is an observable poise in the posture and an ease and lightness in the quality of movement. It is also noticeable that there is an increased co-ordination between the parts of the body: most importantly, the movements of the arms and the legs are dictated by the movement of the head, neck and back, rather than the other way round.
In the text of the book, for ease of understanding, we have sometimes used the term primary control and sometimes the head/neck/back relationship.

More on the Physiology of the Primary Control
If we take a closer look at the physiology of the head/neck interaction we can see why this relationship is so important. The head weighs approximately 4-6 kilograms, a considerable weight to carry around on top of the spine. (Fortunately for us, we do not experience it as being so heavy.) It is balanced on the top vertebra of the spine at a joint called the atlanto occipital joint. Because it is heavier in front of its pivot point, there is a constant tendency for the head to fall forwards. This is prevented by the coordinated action of the neck muscles, and is why, when someone falls asleep sitting upright and their neck muscles relax their head falls forwards.
There are two muscle groups at the back of the neck that are involved in the balance of the head on the body. An inner layer consists of smaller muscles - the sub-occipital muscles - and their job is to make the continual subtle adjustments necessary to maintain the delicate and freely moving balance of the head on the spine.
Unfortunately, in the majority of people the subtle balancing act of the head on top of the spine is not allowed to function, because the larger, outer layer of neck muscles, which run between the head and upper back, shoulders and collar-bones, are pulling the head strongly backwards and downwards, thus over-riding the function of the sub-occipitals, and strapping the head firmly and immovably on to the body.
It is worth knowing how the brain achieves postural balance. The brain relies on information from the nervous system in achieving the ever-changing task of keeping the body upright. It relies heavily on receiving information from the nerve receptors in the neck muscles (which are particularly rich in nerve receptors, the deepest muscles having up to a hundred times more muscle spindles than most of our other muscles), together with information from our eyes and our balance organs in the inner ear.
When the sub-occipitals are not allowed to function properly, any subtle movement of the head becomes impossible. This lack of neck movement diminishes the nervous information fed to the brain, and contributes to the misuse of the body.
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