In the previous section I wrote that the facilities established while doing Bhastrika prevent formation of gas traps in the lungs.
It should be noted that it shall be possible ONLY in case of correct muscular effort.
What should it be?
1. By inhale it is the diaphragm without participation of the chest muscles that should be involved.
2. The muscular impulse should initiate the exhalation; its further performance is contraindicated.
Let us sort out the details.
As we have already said, the inhalation is done mainly due to the muscular effort that overcomes a series of resistances from the part of the lungs:
— the elastic resistance of the bronchial tree that tends to contract, keeping its original shape (this resistance is referred to as elastic traction of lungs);
— the resistance of the transported air;
— the inertial resistance.
Yet the exhalation is mainly done because of the elastic traction of the lungs — it pulls up the bronchial tree, alveoli and respiratory muscles.
The muscular effort allows creating initial exhalation speed. Further speed and volume of the exhaled air shall not depend upon the muscular effort made (J. West. Respiratory Physiology: The Essentials. M., 1988. J. West. Pulmonary Pathophysiology. M., 2008). (1)
Thus we use the activity of the expiratory muscles at the very beginning of the exhalation. We use the abdominal muscles since the diaphragm at this period is not contracted but relaxed, getting back to its original position.
If we try to further push out the air from the airways amid and at the end of the exhalation cycle, the only thing this will lead to will be the formation of the gas traps that we actually want to get rid of.
The matter is that the driving force of the exhaled air is the pressure drop occurred within the system “the alveoli – the nasal cavity”.
In the pause between the inhalation and the exhalation this force is equal to “0” – the pressure in the stretched alveoli is just the same as the pressure in the nasal cavity.
The exhalation starts from alveoli’s gradual shrinking and respective rise of the pressure within them. This pressure is possible due to two forces – the elastic traction of the lungs and expiratory muscular effort that creates the compression from outside, from the part of the thoracic cage. This effort is slightly dampened by the pleural cavity with negative intrapleural pressure.
The pressure difference occurred in the course of exhalation increases and the airstream comes out of the respiratory tract.
There is one trick in here – the pressure from the outside should not be excessive. In case this happens, the elastic bronchial passages shall be shut off and the air shall be sealed in the alveoli (it is this very phenomenon that is referred to as gas trap or gas tapping).
In the practical course of performing Bhastrika it means the following: we should not engage the muscles of exhalation pushing the air completely out by means of the ribcage.
This thesis can be expanded by speculating on the subject that by expiration we use the abdominal muscles, and respectively these are mainly the alveoli of lower lungs that are opened up. That is, it is the place where the air heads to and where the overpressure is formed.
Therefore the exhalation should be formed by pushing the air out from them. The effort done by means of intercostal muscles will lead to increased risk of gas traps formation in the alveoli in which the amount of gas is not that big (2).
In practice it means that in the course of exhalation the air should be supplied as if in an upward direction. The impulse should be formed by the abdominal muscles, while the zone of ribs and diaphragm should be to some extend relaxed and should not resist the effort. The intra-abdominal pressure built by abdominal muscles must involve the diaphragm into the upward movement.
The intercostal muscles should to the extent possible be excluded from the act of active exhalation.
I would like to give here one more interesting contemplation that goes somewhat beyond the scope of this article.
In terms of medicine the diaphragm is traditionally considered to be a muscle that is not subjected to control.
According to research studies the diaphragm is poor in muscular receptors – there are few of them there. The majority of available neuromuscular spindles signify the beginning and the end of inhalation but not its course (Corda et al., 1965; Granit, 1970). According to some authors the contractions of the diaphragm is regulated by receptors of the lungs and intercostal muscles (Glebovsky, 1973). (3)
Under conditions of Bhastika (hyperventilation) the expiratory muscles become active. The intercostal expiratory muscles must be deactivated in order to maintain the ventilation; and in some moment the ability of managing the diaphragm may become necessary. (4)
We must also take into consideration that the accumulation of tension in muscles and lung tissue in the course of performing Bhastrika at some certain point results in one’s inability to cope with it. The excitation as if spreads over the respiratory neurons that control the respiratory muscles and it ceases to be local (the effect of temporal and spatial summation).
At the stage of mastering the set task any zones that a person can produce exhalation with will be actively involved. Up to reproduction of archaic reflexes – the activation of intercostal muscles, neck, shoulders and so on. (5)
Those who have tried – they do know.
And intercostal-phrenic reflex is no exception: the intercostal muscles are those that are most actively involved.
In the described conditions it is only by means of conscious action that a person may maintain the optimum of the move. It is not the body with its habitual reflexes that chooses. The one to choose is the man. Who learns to choose. Under his own established conditions of necessity of sophisticated management of the system that would have not been actualized beyond the state of total tension. To my opinion this state comes as an essential prerequisite for forming the capability of subtle, point-like control of one’s body. Of each individual muscle.
By means of creating conscious effort we may destroy the obsolescent reflexes and form new interneuronic connections, new functional centers in the brain (A. P. Anokhin).
While the objective of the breathing system is the provision of uninterrupted air conduct, the task of the man is that of skillful management of the most complex, multicomponent respiratory apparatus.
Yoga gives instruments for such management. For taking care of one’s body. For one’s transformation.
To be continued…
The above-given figure shows the air flow curves under conditions of various expiratory muscular effort. They differ only in their initial point – this speaking for independence of the air flow from the muscular effort halfway through and at the end of the exhalation.
(2) The model is in a certain way simplified (the air has the ability of moving within the lungs).
(3) We spoke about intercostal-phrenic reflex in the section 1.
(4) But this is a question for further research in the field of Yoga-therapy. And for more “volumetric” type of breathing – such sophisticated manipulation with the diaphragm is better mastered when in slow pace.
(5) I. S. Breslav in his analysis of respiration system draws attention to the fact that in terms of phylogeny (in the process of development from one species to another) the ventilation of lungs was evolving from locomotor movements of the body. (I. S. Breslav., 1981; I. S. Breslav. Beathing Patterns, 1984.). In this scope the act of inhalation complies with unbending (stretching), while the one of exhalation – with bending of the body.
In continuation of these speculation [we should say that] these movements may be also associated with emotional states of the practitioner, his behavioral patterns (A.G. Safronov. Yoga: Physiology, Psychosomatics, Bioenergetics).
Yoga-Therapist, Yoga instructor
23. 09. 2014