Paschimottanasana

The name paschimottanasana is literally the posture of the intense stretch of the west. Paschima means west, and in the anatomical vocabulary of these texts it also means the back of the body. The two senses are joined by an assumption about how a practitioner sits: facing the rising sun, so that east is in front and the spine faces west.

That convention is not incidental. Orientation matters throughout South Asian ritual practice, in the siting of temples, in the direction a householder faces for domestic rites, and in the arrangement of the fire altars of the older Vedic ritual. A technical term for the back of the body built out of a compass direction records a world in which practice was habitually oriented, and it is one of the small places where the hatha corpus shows its inheritance without arguing for it.

The Hatha Yoga Pradipika describes the posture as the legs extended straight, the toes caught in the hands, and the forehead brought toward the knees. The Gheranda Samhita carries it as well, placing it in the stock shared by both manuals. It is one of the few postures in the earlier text that neither sits cross legged nor balances on the arms, which makes it slightly anomalous in a list otherwise composed of seats.

Svatmarama makes an unusually specific claim for paschimottanasana. He says it drives the breath into the sushumna, the central channel of the yogic body, kindles the gastric fire and makes the belly lean. Those are the text's statements, recorded here as the text's and not repeated as effects.

The claim about the central channel is the one that shows what the posture chapter is for. In the physiology the hatha corpus assumes, the breath ordinarily runs in the two side channels, ida and pingala, and the whole apparatus of breath restraint, locks and seals exists to redirect it into the sushumna, which is what the tradition says opens the way to the states described in the later chapters. A posture credited with doing that work directly is being placed close to the centre of the system rather than treated as preliminary conditioning.

The gastric fire, agni, belongs to a related set of ideas in which digestion is the model for transformation generally, and heat is the agent of it. Claims about kindling that fire recur across the corpus and attach to several postures. Geoffrey Samuel's Origins of Yoga and Tantra sets out the development of the subtle body physiology these claims depend on, and reading the posture chapter with that framework in view makes clear that the manuals are not describing exercise with incidental religious language attached.