Uddiyana Bandha
In Sanskrit, Uddiyana means "to fly up," "to rise up" or "upward" and Bandha means "to lock," "to hold," or "to tighten," therefore this practice translates to "to rise up or upward lock."
This practice is an abdominal lock which activates Manipura Chakra. This is one of ten Mudra practices that are said to destroy old age and death as well as giving Divine wealth.
In Sanskrit, Vishnu refers to the Supreme Consciousness and Granthi means "knot" and is known as Vishnu Granthi. This knot is associated with Manipura Chakra and Anahata Chakra, as well as the Pranamaya Kosha meaning "the energy body" through Manipura Chakra, Manomaya Kosha meaning "the mental body" through Anahata Chakra.
Because of the two Koshas meaning "sheath" or "body" are being affected, the Annamaya Kosha meaning "the physical body" is also affected.
Some beginners may find preforming this practice is easier when done in Tadasana rather then a seated position and after some experience has been gained, the practitioner can move to a seated position.
This practice is also included in some Pranayama practices and it is highly advisable to be experienced with this practice before incorporating it with Pranayama.
This Bandha is similar to the practice of Tadagi Mudra because with both practices the abdomen is brought inwards towards the spine creating a concave curve to the abdomen.
Practice
Sit in a Meditative Asana or Tadasana with the feet slightly apart.
Bring the hands to the thighs, just above the knees and slightly lean forward.
Contract the abdominal muscles, pulling the belly in and upwards. Feel as if there is a suction from a point just behind the sternum. This will enable the abdomen to go fully inside pressing all the abdominal organs against the back wall of the spine.
Hold the lock with the breath outside for as long as you are comfortable.
The six cleansing actions are intended to be the start of a Yoga practice in order to clean, strengthen, remove toxins and improve the flow of Prana through out the practitioner.
Yoga poses help to elongate and strengthen the muscles of the body as well as to calm the mind for the deeper spiritual practices of Yoga.
Breathing exercises are a great practice to remove carbon dioxide, increase lung capacity as well as being a good preparatory practice for the deepest spiritual practice of Yoga, Meditation.
The four body locks that makes up this practice give the practitioner the ability to hold or lock Prana in certain locations of the body. These practices also allow the practitioner to release blockages that may be holding the practitioner back.
The gestures in this practice include the whole body and are intended to awaken Prana, Chakras as well as Kundalini energy within the practitioner.
Meditation is the highest spiritual practice of Yoga which is why this practice is the most difficult practice to preform, but with correct knowledge and dedication, can be the most profound practice of Yoga.