Kundalini yoga is not properly understood by many people now a days. They think that it can be practised easily by anybody and everybody. It is a system requiring most discipline in body and mind observing strictly the rules of yama and niyamas. Aspirants of sincere devotion, spiritual yearning and total detachment will come successfully by regular sadhana. Also constant guidance by the Guru is indispensable for the Sadhaka.
We must understand that the body of man is microcosm, a miniature universe and it is part of the macrocosm, the total universe from grossest to the subtlest and it is the body of the God. All living beings are the individual souls. Whatever is there in the cosmic body, is represented in the body of the man also. Though the body seems to be solid and material, all the subtle forces are permeated in him. The body of man is made up of the five elements such as earth, water, fire, air and ether and on death all these elements return back to the elements and the jeevatman (subtle body) is transmigrated to the next world according to the spiritual progress. Originally all these elements are the different aspects of atom which has the appearance of a solar system. In an atom nucleus is at the centre and electrons circulate around it. Tissues and organs can be compared to galaxies. As there is space inside the solar system between planets, so is there space inside atoms. So it is evident that man and all creatures do not have the same look as they appear. The atoms are attracted together to form cells and cells to form various tissues and organs. This attraction is due to a magnetic force called prana (life force) present in the body. Prana connects the mind to the body and mind to the Soul which does not work direct on body which is only a collection of atoms. So the Soul can work only through the mind. Prana is more subtle than the body, mind is again more subtle and Soul is the most subtle. Hence the subtle forces control the lesser forces and the body has no power over the subtle forces. All these facts are to be kept in mind when Kundalini yoga is practised.
Kundalini power is the primal force of the universe and is present dormantly in all living beings. As it is the most subtle force there is no way to identify it through physical senses. Through the yogic methods this force can be enlivened and man can be emancipated to God realization. In the common man Kundalini power is lying dormant at the base of the spinal cord inside Sushumna nadi (a subtle channel inside it). Two other channels on the left side of spine called Ida and at the right side Pingala are also connected with the practice of Kundalini yoga. These channels are represented physically as sympathetic and parasympathetic nerves. They control all the functions of the internal organs in the body on either side of the spine.
There are seven chakras (lotus like round wheels) inside the spinal cord called Mooladhara at the base, Swadhisthana against the sexual organ, Manipura against the navel, Anahatha against the heart, Visudhi at the back of the neck, Ajna at eyebrow centre and Sahasrara at the top of the head. Corresponding nerve centres are seen to indicate the physical presence of these particular chakras in the spinal cord. Since all these chakras exist in the subtle body, (pranic body), they are not visible for the physical eye. By long practice of meditation or by the Grace of a Guru, the Kundalini power will rise through the chakras and reach at Sahasrara chakra and such a person is supposed to reach God. It is not safe to practise this yoga without the help of a realized Guru who can guide the aspirants how to meditate on the chakras.
From the picture you may understand the position of chakras in the body. Each chakra (lotus) has particular number of coloured petals which represent different powers. In Mooladhara there are four dark red petals, in Swadhisthana six light yellow petals, in Manipura ten orange red petals, in Anahatha twelve grey coloured petals, in Vishudhi sixteen blue petals and in Ajna two bright white petals. In Sahsrara there are thousand petals indicating infinite powers.