To ensure that we get an adequate supply of oxygen it is helpful to understand how we actually breathe. There are two main types of breathing : costal (meaning “of the ribs”) or chest breathing, and diaphragmatic or abdominal breathing. Only when we take a maximum breath is a third variety used, known as clavicular breathing.
COSTAL OR CHEST BREATHING
This type of breathing is characterised by an outward, upward movement of the chest wall. In chest breathing the expansion is centred at the midpoint and consequently it aerates the middle part of the lung most. Since the lower part of the lung is most abundantly perfused with blood, we have that ventilation perfusion mismatch described earlier. Thus during resting periods chest breathing is less efficient. Chest breathing also requires more work to be done in lifting the rib cage, thus the body has to work harder to accomplish the same blood gas mixing than with diaphragmatic breathing, and the greater the work, the greater the amount of oxygen needed, which results in more frequent breaths. Chests breathing is useful during vigorous exercise but it is quite inappropriate for ordinary, everyday activity. Since it is part and parcel of the fight or flight response it occurs when the individual is aroused by external or internal challenges or danger. As a result, chest breathing is likely to be associated with other symptoms of arousal like tension and anxiety. Since there is a reciprocal relationship between breathing and the mind, chest breathing, if continued during rest periods, will lead to tension and anxiety, thus creating a vicious circle. With chest breathing the breath is likely to be shallow, jerky and unsteady, resulting in unsteadiness of the mind and emotions. Until chest breathing is replaced by deep, even and steady diaphragmatic breathing, all efforts to relax the body, nerves and mind will be ineffective.
ABDOMINAL OR DIAPHRAGMATIC BREATHING
The principal muscle involved in abdominal breathing is the diaphragm, a strong dome-shaped sheet of muscle that separates the chest cavity from the abdomen. When we breathe in, the diaphragm contracts and pushes downwards, causing the abdominal muscles to relax and rise. In this position, the lungs expand, creating a partial vacuum, which allow air to be drawn in. When we breathe out the diaphragm relaxes, the abdominal muscle contract and expel air containing carbon dioxide.
Of the two major types of breathing, diaphragmatic breathing is the most efficient because greater expansion and ventilation occurs in the lower part of the lung where the blood perfusion is greatest. In children and infants the diaphragm is the sole muscle for respiration, so if you watch an infant breathing you should get a good idea of what diaphragmatic breathing is like. As the diaphragm contracts it pushes the abdominal organs downwards and forwards, and this rhythmical massage gently compresses the organs and improves circulation. Diaphragmatic breathing in conjunction with physical and mental relaxation has been found to reduce high blood pressure and anxiety significantly.
When we are calm and composed our breathing is diaphragmatic, and since there is a reciprocal relationship between breathing and the mind, practising diaphragmatic breathing leads to mental relaxation. It is the most important tool available for stress management. It promotes a natural, even movement of breath which both strengthens the nervous system and relaxes the body. It is the most efficient method of breathing, using minimum effort for maximum oxygen.
The following are the main benefits.
• Providing the body with sufficient oxygen.
• Expelling carbon dioxide adequately.
• Relaxing the body and the mind.
• Improving circulation to the abdominal organs.
Clavicular breathing is only significant when maximum air is needed. The name is derived from two clavicles or collar bones which are pulled up slightly at the end of maximum inhalation, expanding the very top of the lungs. It comes into play when the body’s need for oxygen is very great. This type of breathing can be seen in patients with asthma or chronic bronchitis.