What is the interest of a yogi about the art of vocal?
Let us come back to diaphragm.
I shall remind that this is the muscle that separates the chest and the abdominal cavity and its efficiency determines the state of the organs located above it and under it. To have it in a metaphoric way, by dividing the body into upper and lower parts it at the same time unites these parts through its movements. You may find details in my article "The Case Study of Today is Diaphragm".
Just like the rest of the muscles – in case of concentric contraction the points of its attachment approach each other and it flattens out. There is another type of muscular contraction – the eccentric, when the places of the muscle attachment move away from each other. So that the diaphragm moves actively upwards increasing the cupula. In the first case the rib cage volume increases – here comes the inhalation, and in the second case it reduces – this is the exhalation.
So, what does yoga have in its store for working with this muscle?
This is, first of all, the full yogic breath (you can find more information on it in the afore-mentioned article). This is probably the perfect pattern of the diaphragm work - the interchange of contraction (concentric) and laxation of muscle fiber, i.e. reduction of a muscle followed by its return to the reference length.
Second, the practice of concentric (shortening) contraction of this muscle comes as conscious preservation of the diaphragm in the state of inhalation. It is held in the dropped state of lower ribs’ expansion (the “stretched trampoline”) and comes slightly down, as if during “straining” (the state that mothers know from their delivery experience and that is familiar to those who tried to overcome constipation). I think it is this practice of Tadagi-mudra that they describe in “Gheranda-Samhita”
3.61. Sitting in Paschimottana-posture, make a stomach full a lake. This is the Tadagi (lake-like) Mudra, the destroyer of decay and death. /Gheranda-Samhita/
Third, the practice of diaphragm relaxation and its eccentric (extensional) contraction due to active work of the abdominals is the Uddiyana-bandha. Here the diaphragm is held in the state of exhale – in its uppermost position.
3.10. Contract the bowels equably above and below the navel towards the back, so that the abdominal viscera may touch the back. He who practices this Uddiyana (Flying up), without ceasing, conquers death. The Great Bird (Breath), by this process, in instantly forced up into the Sushumna, and flies (moves) constantly therein only. /Gheranda-Samhita/
From this point of view the Kumbhaka (ceasing of breath at inhalation) can be performed in two options:
1. With diaphragm’ high stand – with Uddiyana-bandha
2. With diaphragm’ low stand – with Tadagi-mudra.
In the first case the accent shall be laid on increase of intrathoracic pressure, with mild impact on intercostal muscles and exercising influence on cardiovascular and pulmonary system (for details see A.G. Safronov, Yoga: Physiology, Psychosomatics, Bioenergetics”, pg. 78).
In the second option the increase of abdominal pressure, active pressure of diaphragm on liver and widening of inferior vena cava shall increase the dark blood outflow from lower body; the venous return to the heart and the volume of blood passing through lungs shall be increased and the process of respiratory metabolism shall be intensified.
The second variant of Kumbhaka (don’t forget about Mulabandha and Jalandhara-bandha) is indicated in case one suffers from lower pelvis engorgement - reproductive organs diseases, lower limbs’ varicose vein disease, G.I. tract engorgements.
I think that in consideration of our tasks we will be interested in paradoxical respiration used by vocalists. In order to have a nice “flying” sound they use “singing from the diaphragm” that in its performance resembles much the tadagi-mudra. During inhalation the diaphragm works according to classical variant (fyb) while at exhalation it is kept in the dropped position “sealing” the abdominal cavity.
Shall we sing? The sound “A”, for instance. Inhale (expand the lower ribs, drop the diaphragm and now lift the ribs supporting against the diaphragm). Hold the diaphragm and sing ‘A’ while exhaling, using the lower abs to regulate the air intensity. And reflect upon this….