Bandha's are "energy locks", a muscular contraction within the body, this contraction binds the circulation of prana, our life energy.
Uddiyana Bandha is a a powerful abdominal lock, also known as the "upward flying lock" in which you pull your entire abdominal wall in toward the spine and up. This energetic action moves energy from the abdomen up into the head.
The practice of Uddiyana bandha is part of a pranayama practice. It is generally done on an empty stomach. After a complete exhale you pull your whole abdominal area in towards the spine and then lift it all up into the chest. This practice can be done standing or in a seat. Some of the benefits of this bandha are that it massages all of the abdominal organs, including the heart, lungs and the solar plexus,this practice also strengthens the abdominal muscles and diaphragm.
We do not fully engage Uddiyana Bandha in our practice, but the action of pulling the belly in and up towards the spine as you pull the front ribs in to the center, assists and creates the light energetic action of this bandha and allows your core to engage and bring in the action of "Lift up".
As you become more comfortable with pulling into the core, you will feel your inner fire grow and a "lightness" to your practice.
This bandha is especially important to engage during back-bending poses such as wheel, bow, and dancer to protect the spine.
With practice Uddiyana Bandha becomes more automatic during poses. Try bringing this bandha into different poses in your yoga practice to bring your practice to the next level.