Mula bandha

The classical (historical) definition of MB, as I understand it, goes something like this: The practice of Mula Bandha directly causes the awakening of the 3 1/2 coils of the serpent Kundalini, initially dormant at the Muladhara Chakra, which unravels its knots (3 and 1/2 coils representing the three Granthi and one last twist representing sublimation that lies beyond the three representations of the Guna), piercing the tailbone, up the golden thread of the Sushumna Nadi to the Manipura Chakra. If this occurs during an Asana class then I am surprised!