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 sh