Ashtanga vinyasa yoga one of the three key principles in Ashtanga Vinyasa Yoga, alongside breath and drishti. There are three principal bandhas which are considered internal body locks: Both Pattabhi Jois and Sharath Jois recommend practicing Mula and Uddiyana bandha even when not practicing asana. Pattabhi Jois has this to say: (translated quote) "You completely exhale, apply mulabandha and after inhaling you apply uddiyana bandha. Both bandhas are very important... After bandha practice, take (your attention) to the location where they are applied and maintain that attention at all times, while walking, talking, sleeping and when walk is finished. Always you control mulabandha".
Ashtanga vinyasa yoga and never taught by Sharath. However most of his teachers who claim to have been taught by him will teach the above methods, exercises, & postures, even though none of what they teach is part of the Ashtanga method of instruction under Sharath. Pattabhi Jois also did not require students to independently drop back and come up from back bending before progressing to the 2nd series. Sharath changed the requirements, and has now made this mandatory. However, it is important to note that Pattabhi Jois was the founder of the system, and taught each of his original students differently, instructing