The spine (Meru Parvata) is very important for any Yogi. The Meru is a metaphor for the spine. It is called the axis of the world for a very specific reason. In Vedic terminology, the physical body is very much equivalent to the Earth. This is because whatever the body acquires (food) is from the earth. So it is a part and parcel of the earth itself. And Meru is the center because without this Merudanda there is no world. This is because without the spine connected to the brain, there's no experience of the world (as can be seen in paralytic patients).
But when the spine is crooked, still attainment is possible only if the individual is able to remain in a posture for more than two hours (Asana Siddhi) without his attention drawn to his physical body. Otherwise, it is extremely difficult because his mind cannot dwell on any thought or topic for long (Nidhidhyasana) because the body keeps moving and distracting his attention.
D.: Which posture (asana) is the best? M.: Any asana, possibly sukha
asana (easy posture or the half-Buddha position). But that is
immaterial for jnana, the Path of Knowledge.
D.: Does posture indicate the temperament?
D.: Does Maharshi advise any physical posture for the Europeans?
M.: It may be advisable. However, it must be clearly understood that
meditation is not prohibited in the absence of asanas, or prescribed
times, or any accessories of the kind.
D.: Does Maharshi have any particular method to impart to the
Europeans in particular?
M.: It is according to the mental equipment of the individual. There is indeed no hard and fast rule.
A Muslim visitor asked about asana (physical posture).
M.: Abidance in God is the only true posture
D.: What is the need then for pranayama?
M.: Pranayama is meant for one who cannot directly control the thoughts. It serves as a brake to a car. But one should not stop with it, as I said before, but must proceed to pratyahara, dharana and dhyana. After the fruition of
dhyana, the mind will come under control even in the absence of
pranayama. The asanas (postures) help pranayama, which helps dhyana in
its turn, and peace of mind results. Here is the purpose of hatha
Later Sri Bhagavan continued: When dhyana is well established it
cannot be given up. It will go on automatically even when you are
engaged in work, play or enjoyment. It will persist in sleep too.
Dhyana must become so deep-rooted that it will be natural to one.
D.: There are several asanas mentioned. Which of them is the best?
M.: Nididhyasana (one-pointedness of the mind) is the best.
Edit 1: I missed mentioning that Kundalini auto corrects so many abnormalities when it begins to rise. Because innately it is energy and energy determines the memory surrounding it and memory determines the physical entities (body) surrounding it.
Edit 2: Added some references for para 3. Though no direct references are potentially possible, there are a lot of contextual references.
PS: I had Chronic back pain for many years due to disc bulges. It rendered me physically very weak and with a crooked posture. But it also taught me how to sit erect. Now wherever I sit and whenever I sit, my spine is naturally erect (even while sitting on a chair) and I don't lean against the back rest either.
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