When the energy is moving properly, you are bound to become healthy, strong and peaceful, radiating strength and vitality to others. Flexibility of the body, especially the spinal cord, and flexibility of the mind are interrelated. Flexibility of the mind means adaptability. Its opposite, rigidity of mind, is called ego. As ego puts stress upon the nervous system, it creates a rigid body. Yoga says that flexibility of the spine and flexibility of the mind are interrelated. If you keep the spinal column flexible, you will have a flexible mind, and you will find that the flexible mind can do more work than the inflexible mind. The more powerful but rigid tree cannot stand against an onslaught of wind or flood. The proud giants of the forest remain stiff, not moving an inch, only to be rudely uprooted. Grasses bow before the gale and again raise their heads to the midday sun. The humble servant prostrates to all and serves until retired by old age, while his unbending master is envied, only to have a fall. The ordinary servant goes on.
For a spiritual aspirant especially, flexibility is necessary. Once the prana starts to increase, any resistance will prevent its free movement. Every morning you should practise asana, pranayama and mantra japa, the repetition of God’s name. Flexibility of the spinal column will allow this vital energy to flow properly. Instead of going downward, it will rise upward. It’s just like water, which, in a gross state, flows downwards, but when in subtle form, like steam, rises. In the same way, a flexible spinal cord will allow your energy to flow upward, past the lower energy centres, chakras, and up to the higher centres. This is what is meant by the ascent of kundalini shakti. The shakti, or cosmic energy, which is stored in your lowest chakra, is called kundalini. It is like the spring in a watch, tightly coiled from being wound, so that when released it makes the watch hands move.
The kundalini energy is condensed, it is potential. It is coiled and lies in a dormant state in most of us. Through the persistent practice of asanas and pranayama and other hatha yoga techniques, this energy unwinds, releases and rises up to the higher centres. For spiritual evolution, it is important to raise the energy to the higher centres. We perform the asanas and pranayama to attain mental flexibility and to get the prana moving properly, removing blockages. As it is stimulated, each chakra releases a specific wavelength of energy stored in it like a battery. As it rises the voltage increases. The lower chakras may have, for example, only six volts, but as you go up, you encounter 10, 50, 100, 1,000 volts. Now you can see the interrelationship between your physical body and physical-mental flexibility. We perform the physical exercises to attain mental flexibility and to get the energy moving properly, removing blockages in the centres. When the energy is moving properly, you are bound to become healthy, strong and peaceful, radiating strength and vitality to others, to your family, to your loved ones and to your friends. Then, wherever you go, whoever you meet, they will all draw energy from you; your mere presence will bring them energy and strength.