So Uḍḍīyana Bandha is the technique
for introducing Mūla Bandha.
Uḍḍīyana Bandha elevates Mūla Cakra,
having elevated it, you tie it
and each time it wants to slide
back down, you bring it back up.
Therefore opposite to techniques such as
Bhujaṅgāsana, which is counter to the principle
of Uḍḍīyāna and pushes the Mūla Cakra down.