Kampana is the vibrations activated through pranayama and it
is experienced by a student of yoga in two different ways. Kampana or
angamejayatva is the trembling of the body and it is one among the five
situations which arise in the wake of the nine obstacles in the path of Yoga.
It is mentioned in Yogasutra (I.31).
The trembling of the body parts, caused by lack of
stability, is a situation which puts an obstacle in the practice of posture for
sitting in meditation.
To overcome the obstacle, Patanjali has recommended the practice
of Ekatattvabhyasah (pinpointedness) (I.32)
Another way of experiencing trembling is associated with
prolonged practice of Pranayama (breath control). It is described in Hathayogapradipika
(II 11 – 12). It is recommended by Swatmarama that a sincere student who wants
to drive the full benefits of pranayama should practice if four times each day.
And at each sitting one should practice eighty kumbhakas, that is, holding the breath
inside the lungs.
The duration of each kumbhaka is measured according to three
standards.
The lowest standard means holding the breath approximately
twelve seconds in each kumbhaka.
The middle standard is of kumbhaka for twenty four seconds,
and the highest stand includes each kumbhaka for forty seconds or more.
Practicing three and twenty kumbhakas of the lowest measure every
day leads to profuse sweating of the body. The middle standard gives rise to
kampana, ie a tingling sensation along the spine. This is an indication of good
progress.
Source
- The Patanjala Yogasutra (1941) by Bengali Baba – published by N R Bhargava Pune
- Hathayogapradipika (1949) by Srinivasa Iyengar – Theosophical Publishing House, Chennai
- Encyclopedia Of Hinduism Volume V page 439 IHRF