Observing all the conditions, lift the right foot, knee straight,
as high as possible, then slowly release it, then lift the left in
the same way.
The movement should also be done in quadruple rhythm. The lift should be
slow, and there should be a decided staying of the activity, and then a
very slow release; then complete rest.
The effect of this exercise is to accentuate further the idea of rhythm;
that is, it requires alternate activity and passivity in sequence or a
continuity of co-ordinations.
In performing this exercise almost an ache may be felt at the back of
the legs, especially at the back of the knees. This is due to the fact
that these muscles become too short in sitting and therefore need
extension. This exercise gives extension to these muscles. Similar aches
will always indicate a lack of extension and call for special help and
practice of the opposing muscles.
Of course, it can be seen that whenever parts of the body, such as the
knees, are kept bent, the muscles at the front of the limb will grow too
long and those at the back of it, too short. Hence, when a man stands up
there is a tendency to stand with the knee bent. Old men have a lack of
firm backward spring in the knee. It is the aim of several of the
exercises to cure this.