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.
14. EXTENSION OF THE BACK
With the body well expanded, kept straight, breathing free and full, lift the hips bearing the weight upon the back of the shoulders and the heel.
This exercise needs to be practiced with quadruple rhythm slowly. It gives wonderful exercise to the central muscles and organs of the torso.
15. ELEVATION OF LOWER LIMBS
With the body well extended and all conditions sustained, lift both legs, knees straight, hold, slowly release, then completely rest.