Uddiyana Bhanda is located at the diaphragm level, or the element at the solar plexus (fire). The heart opens up the higher center (heart chakra), which is the center of true love, kindness, and compassion. It separates the love triangle where instinct and reaction takes places, from the upper triangle of the body, where more conscious acts come from.
To apply Uddiyana Bhanda one must breathe in and out completely, and while maintaining the breath out hook the abdomen in and up. Hold this position for around one minute (more or less depending on your endurance). Contrary to Mula Bhanda, Uddiyana Bhanda can be seen by the naked eye very easily. Once you breathe in again the diaphragm moves and the lock releases. Never apply this lock on a full stomach.
In Asthanga Yoga you will always hear about maintaining Mula Bhanda and Uddiyana Bhanda through all the sequences. This can be confusing because breathing in unlocks the diaphragm. What it really means its to maintain a sense of hold at the diaphragm.
Bhanda Table of Contents