11. Use in every exercise, as far as possible, all the primary actions of the muscles.
We can distinguish four actions of the muscles. First, active contraction, shortening of the muscles sometimes called concentric contraction; secondly, we can stay the tension of the muscles at a certain point. This is called static contraction. Third, we can allow the muscle gradually to release its contraction, that is, allow it to slowly lengthen. This is called eccentric contraction. Fourth, we can take the will entirely out of a muscle and allow its complete quiescence.
Rhythm demands the presence of all these actions; and also all these elements in proportion. And in the practice of all exercises it is well to accentuate all four of these elements by counting. In the stretch for the whole body, for example, we can extend the limbs slowly as far as possible, and there will be a contraction of the extensor muscles. Then we can stay the body when stretched to the fullest extent. Then we can gradually release the action of these muscles and then completely rest.
Some of the exercises can be practiced with dual movements, first with activity and then release, but by varying the climactic action for a moment and gradually releasing, that is, by giving these a quadruple rhythm, we can accomplish better results than in the dual.
In dual rhythm we are apt to collapse suddenly after a movement. In fact, it is harder to control the release of the contraction of the muscles than to control the gradual increase of their contraction. This is illustrated in the difficulty of retaining breath. Breath is normally retained by sustaining the activity of the diaphragm, that is, its eccentric contraction. However, the body needs occasionally the complete surrender of muscles, but this should not be too sudden or jerky. The gradual surrender brings greater control and the higher type of development.
When we use what are known as secondary movements, that is, when we use the hands to manipulate the stomach or when somebody else rubs us, we should restfully and completely give up the muscles and manipulate them or let them be manipulated in a state of rest.
At times it may be well to manipulate a muscle when at full tension. When there seems to be a tendency to great constriction it may be well to manipulate a muscle during both contraction and relaxation and to test its relaxation. Again if a muscle does not seem to act as far as possible the opposing one may be found too short and may be manipulated to allow greater extension.
12. Practice thoughtfully.
That is to say, study yourself. Observe your needs. For example, stand against some perfectly straight post or door, with the heels and back of the head against it. Where the back curves most, there will be room for the hand. Now where do you feel the most constriction? Give attention to such parts.
Even when lying on your back, by stretching the limbs and expanding the chest such wrong tendencies or faults in standing can be corrected. The chest can be set free when it is constricted. When it is carried too low you can directly separate the breast-bone from the spine. By sympathetic expansions of the torso and by manipulating with the hands the parts that are especially constricted, curvatures, even in the back, can be improved.