One of the potentials in the Haṭha Yoga teachings of Krishnamacharya and Desikachar is the understanding around the viniyoga or application of Bṛṃhaṇa Kriyā and Laṅghana Kriyā in terms of their potential to enhance sensory stimulation or to diminish sensory stimulation.
Both approaches can be used where appropriate to impact on how we are stimulated by the world through the senses and thus be more drawn to interact with it in a more extravert way, or how our sensory stimulation is quietened and thus we are more easily able to withdraw from the activities of the senses.
Both approaches are valid and applied according to our changing age, life situation and life stage. Here the role of a teacher is helpful in learning the skills of self application within our daily practice. We can learn how we can fine tune our practice according to our basic nature and where it needs to be within day to day living and its demands.
This alchemical process would also be difficult to explore other than in some very generalised way within a weekly group class given the mix of the age, gender, interests, needs, potentials and core physiological, energetic and psychological natures of the students.
Let alone where they are in their life circumstances, external demands, work roles and life stage or even the teacher having time and situation to explore each student personally to gain some insight into what is happening at that life moment within the small window offered by time and group size.
Hence throughout Krishnamacharya and Desikachar’s teaching life, apart from group classes for children and young adults, they taught only personal lessons.