In yoga, the significance of mudras and bandhas is even greater than that of asana and pranayama, because mudras influence pranamaya and manomaya koshas. In the body, many sensations originate within the nervous system and many changes take place on the mental plane. In the pranic field, the production of energy in the body also fluctuates. For these reasons, both activity and dissipation are experienced in the inner mental state and also in the pranic state.
From the gross point of view, mudra is a term meaning a gesture or a particular mood or feeling of consciousness. The mudras described in the yogic scriptures are manifestations of special moods or feelings of consciousness, chitta, and states of energy, prana. Knowledge of mudras and their techniques is known to very few sadhakas, practitioners.
In Indian dance, different mudras or gestures are used to depict a particular mood or feeling. Anger is depicted through the eyes, the position of the hands and the physical posture. This is just one example. It has also been observed that if a particular mudra is practised for longer periods of time, a feeling created by that mudra is experienced. The same kind of sensation depicted by the mudra is created in the body and mind. This also happens in daily life. For instance, an angry person raises the eyebrows, tenses the hands and clenches the fists. Even if one is not angry, this feeling will gradually manifest if these physical actions are adopted. Whichever physical state is adopted creates a particular kind of sensation in the nervous system and brings about a change in the brain waves. This change in the brain waves influences the state of consciousness and for some time that particular feeling is experienced inside on the mental plane.
The mudras and bandhas which have been described in the yogic texts are helpful in putting to rest and controlling the sensations and stimulations of the nervous system. The mudras known in yoga are often shown in portraits, images or idols of saints and sages or gods and goddesses, for example, jnana mudra, chin mudra, shankh mudra and abhaya mudra.
Mudras such as ashwini mudra, vajroli mudra and tadagi mudra are practised in kundalini yoga and kriya yoga. These mudras influence pranamaya kosha and are used to change the flow of prana. Their influence is felt on the brain as well and they help in awakening a certain feeling inside chitta so that one becomes introverted and internalised. These practices are also helpful in achieving one-pointedness and concentration.
The bandhas are in fact physical and psychic locks which disrupt the sensations being created in the nerves inside the body and brain, and awaken other specific kinds of sensations. Any process of contraction or expansion in the internal organs, whether in the neck, throat, perineum or anal region, changes the reactions, emotions and the quantum of energy in the internal organs. It brings the body to a stimulated or peaceful state, resulting in the experience of a feeling of inner stability.
Many philosophies, religions and systems of thought in the world believe that it is necessary to completely detach oneself from the external world in order to experience some sort of spiritual or inner realization. The main aim of mudras and bandhas is to help attain an inner state in which external emotions and events do not scatter the mental state. One should be able to keep the mind one-pointed in prayer or meditation and not allow any negative feelings or reactions to manifest internally.
It is said in Vedanta that everything is transitory; it is all maya, illusion and delusion – leave it, and abide in the truth. But in yoga and tantra it is said that whatever state one is in should be used as a ladder to higher states. Yoga believes that if one wishes to attain one-pointedness and some sort of spiritual experience, that experience can be achieved through the medium of the senses also. The senses may be expanded and activated so much that the mind spontaneously becomes one-pointed. Mudras can play a role here; for example, khechari mudra is related to the senses.
Sage Gheranda describes the process involved in the practice of mudras and bandhas. One can activate, expand and absorb oneself in the sensations manifesting inside by adopting a particular technique. Making use of physical and psychic gestures activates the sensations of annamaya kosha, pranamaya kosha and manomaya kosha in order to go inside them.