Different Types of Postural Activity in Āsana Practice

12. Finally, the consideration of movement
or stasis sits within a relationship to the
deeper purpose of Āsana within our journey
through the body and the breath, to the mind
and beyond, through considerations such as:
In relation to the psychological ideal of remaining there.
According to the definition in  Chapter Three verse 2 of
the Yoga Sūtra, a continuity of psychic activity is the ideal.
This is seen as the ability to stay, as if in the same moment, as
one moment melds into the next moment and the next moment.
In other words, the ability to internally maintain a continuity of
experience as if maintaining an apparent stillness of movement.
Access to such subtle states requires a containment of movement
that ultimately extends from the body to the breath to the mind.

Āsana Mudrā & Prāṇāyāma
– Collected Viniyoga of Practice Planning Principles

Āsana Mudrā & Prāṇāyāma
– Collected Practice Planning and Practice Theory Questions