Mudra and Bandha
Energy locking techniques
Mudra and bandha bring stability to the mind. They work at a much deeper and subtler level than asanas. They balance the elements and develop awareness at the level of the organs. They purify the cells and cleanse the organs. A mudra is a particular posture that channels energy into particular chakras (plexus) and in turn affects the organs to which it is connected. Bandha means lock. It involves contraction of the muscles and organs causing energy to accumulate at a particular plexus. The Yoga text, Gerandha Samhita gives 26 mudras that can be subdivided into a total of 55. A further 11 Mudras are explained in the Siva Samhita.
At the moment we have no control over our organs, but an advanced hatha yoga practitioner can control their organ function through these techniques. For example, one of the benefits of kechari mudra is to control and regulate the thyroid gland and the production of T3 and T4 hormones that affect the metabolic rate.
Some mudras and bandhas are performed with asana and pranayama while others are practiced following them separately. For example, Vipareeta karani mudra, is a shoulder stand practiced with the back at a 45 % angle to the floor. It should be practiced in the sequence of asanas before sarvangasana, the straight shoulder stand. It stimulates the thyroid and purifies the visuddhu chakra (pharyngeal plexus). Similarly, Uddhiyana bandhana, is practiced in the sequence of pranayamas. It involves sharp exhalation and holding of the exhaled breath, while retracting the abdomen and holding it inside until an inhalation is required. Kechari mudra, that involve swallowing the tongue however is practiced after asana and pranayama.
As is always the case in hatha yoga, the sequence of these techniques is very important to ensure that the flow of energy is upward, from the base of the spine to the crown of the head.