In the Yoga Sutras, Patanjali points out the characteristics of Asana in the 2nd chapter...
'It was about time!' one might say, since what we know of yoga today is mainly postures and sequences=Bahiranga sadhana. Yet soon one finds out that the reference to asana has only 2 words: the Asana (any posture) in Yoga should be Sthira (steady) and Sukha (soft) - both mediated by the breath.!
Quite often, the breath becomes compromised by the intensity required to attain a posture or other times, the interaction between the body and breath is becoming mechanical...thus, the relationship between them reinforces confusion.
Just as the strings of a musical instrument require the right amount of tension, so too, each posture requires the right amount of sthira (stability). Too tight is wrong, too loose is wrong; just right, produces sukha! (comfort and ease!)
A very cute description about these ingredients in the composition of asana is not about balancing each other out for a given result (30g of sthira + 30gr of sukha)...instead, they are in constant dynamic play with each other, dance together, give birth to one another..
When one becomes attentive to this interplay, confusion fades away.
It is all about engaging in a relationship (on and off the mat) with the intention to bring a positive change. It is about to get the 'right support', to learn how to use the support, to 'allow' the support to support you, to develop a repeated practice...in modern yoga classes, a 'support' would mean blocks, belts and other equipment. In this context, a support would include postures with breathing techniques, meditation, a sacred chant maybe or a cultivation of certain attitude etc...
A supportive action in Asana is rather often based on a particular bhavana (a focused experience). Poetically given by my teachers it can be based on an image such as:
During INHALATION -> part of the body remains firm and stable (sthira) so the support comes from the abdomen -> another part moves (direction is given from the spine) -> top of the body is opening out into space.
When one experiences an opening of a space (in the body) while feeling supportive, then one experiences sukha.
The reverse movement is happening on the EXHALATION -> upper part of the body remains open and supportive -> the direction moves towards the earth -> the effort to remain open (and don't collapse) is sthira.
The exploration of the sutras has to do with the relationship we develop on & off the mat ~ what are the qualities we bring to ANY relationship and the support taking from it opens a comfortable space in & out ... This is sukha...comfort and ease regardless of external disturbances...🤗🙏
***References from 'Embodying the Yoga Sutras' by Ranju Roy and David Charlton