How to practise
Lay the danda on the floor.
Sit comfortably with the spine, neck and head upright.
Spend several minutes settling the body and mind.
Begin to follow the flow of breath and notice which nostril is dominant. If necessary, block one nostril at a time to check which is flowing more freely.
Once you have discovered the active nostril, place the danda firmly under the same armpit as the active nostril. i.e. right nostril active, place under right armpit. This will open the opposite nostril, creating a balance.
Adjust the danda so there is a comfortable amount of upward pressure under the armpit (see how to adjust pressure below). There is also slight sideways pressure, as the upper arm lightly presses the danda into the side of the armpit/chest.
Feel the position of the body, make sure you are sitting symmetrically with the shoulders at the same height.
Soften the whole body, let the whole body become still and steady.
It is not necessary to do anything but wait for the flow of breath to balance. It helps to follow the breath in the nostrils and also gives the mind something to focus on.
Prana shuddhi: One technique is to follow the flow of air in each nostril, following the air up and down synchronized with the breath. Imagine that the two flows (left and right nostrils) meet at the eye brow center, brumadhya.
Start the awareness at the entrance of each nostril and with the inhalation smoothly move the awareness to brumadhya where the two flows of prana meet, then follow the exhalation back down until the air leaves the separate nostrils. Be aware of the flow of air and prana synchronized with the breath. Follow each breath up and down this psychic pathway. Imagine the flows are equal and gradually they will be.
Once both nostrils are flowing evenly, remove danda and lay on the ground. Practicing in this way creates a balance in the pranas.
Activating Ida or Pingala: If your aim is to activate a paticular nadi, then practice the same as above (prana shuddhi), but with the awareness only on one nostril. Follow the movement up and down from the entrance of the nostril up to brumadhya. To add intensity to the practice, you can visualize the flow in Ida (left nostril) as cool in temperature and blue in colour and Pingala (right nostril) as hot in temperature and red in colour. Keep the danda in position throughout the practice.
It is possible to use the danda prior to pranayama, on its own, with mantra japa, trataka or any other meditation practice.
How it works
A danda works in the same way as Padadhirasana (breath balancing pose), where the pressure of the hands under the armpits balances the flow of breath in the nostrils. Incidentally, lying on your side has the same effect of opening the opposite nostril.
If the pressure is under the right armpit, then the left nostril will open. Ida Nadi (mental energy), corresponding to the para-sympathetic nervous system will be activated and eventually become dominant.
If the pressure is under the left armpit, then the right nostril will open. Pingala nadi (physical energy), corresponding to the sympathetic nervous system will be activated and eventually become dominant.
The benefit of a yoga danda is that it requires much less effort than padadhirasana, especially if practicing for long periods of time. It becomes a useful tool if you are frequently altering the swara, or would like to use a japa mala at the same time as balancing the swara.
The danda can also be placed under the forearm, supporting the arm during mantra japa and at the same time activating the opposite swara.
How to adjust pressure
The pressure of the danda is adjusted by moving the base towards the hip and away from the hip. When the base of the danda is directly below the armpit (near the hip) there is maximum pressure. If the danda is long enough, it will be possible to move the base away from the hip to lessen the pressure. In practice, the danda is likely to be used somewhere between these two extremes.
Please note: If the danda is the correct length, the arm hangs comfortably, there is no contact between the elbow and the danda.
When Sushumna flows, there is a balance in the pranas, a balance in the autonomic nervous system, we experience a state of equilibrium. When this occurs it becomes much easier to practice pranayama and to develop dharana (effortless prolonged concentration) and dhyana (meditation).
Swara yoga states that during the day we switch between Ida and Pingala dominance every 60-90 minutes. A study carried out at the Bihar School of Yoga, India, discovered 60 mins to be the minimum time, but that it often stretched to 3 hours or more.
A danda may be used to activate a particular swara (rather than to balance), but care, common sense and guidance are necessary. After all the body usually knows best! If our practice or lifestyle prevents this natural flow of energy for a prolonged period, then imbalance and disease follow.
"When one swara predominates for more than three consecutive days, some type of mental physical or emotional crisis arises." - Swara Yoga, Swami Muktibodhananda.
Hari Om Tat Sat,
Sanyamatma, founder of Inner Eye Yoga Products.
There's a very interesting article by Dr Swami Mudraroopa in the yogamag archives here.
In medical terminology, swara yoga is often called 'forced unilateral right or left nostril breathing'.
'Swara Yoga' - by Swami Muktibodhananda, Bihar School of Yoga, Munger, India, contains all sorts of inspiring information, including a brief summary from a six month study of the swaras. It also contains a full translation of 'Shiva Swarodaya', a dialogue between Shiva and Parvati on Swara Yoga.
As with all yoga practices, it is best to receive instruction and guidance from an experienced teacher.