This asana has many other names. The most common are ugrasana (fierce or powerful pose) and paschimatanasana, which has the same meaning as paschimottanasana.
Terminology There are many meanings associated with the name of this asana. Literally, the word paschima means ‘the back’, or ‘posterior’; it also means ‘the west’. The word utthan means ‘to stretch’. Therefore, the usual English name of this asana is ‘the back stretching pose’.
The word utthan is also akin to the word ‘tan’, which makes up part of the word tantra (the mother system of yoga). In this context, it is not physical stretching that is implied, but stretching or expansion of awareness. The word paschima still means the back, but has greater significance if it is taken to mean the sushumna nadi. This nadi is the most important psychic pathway in the body. During higher states of awareness, prana ascends this nadi from the bottom of the back (perineum) to the head (sahasrara). In fact, it is said that the experience of higher awareness cannot take place unless prana flows within this nadi. So this asana has a very elevated meaning. It means the asana which expands awareness by unleashing pranic currents which flow upwards within the sushumna nadi. This is a fitting name, for this is indeed a powerful asana.
This asana is widely mentioned in many ancient texts. The Hatha Yoga Pradipika says: “Knees straight and forehead on the knees, hands on toes in a sitting position. It directs vital energy into the back especially in the sushumna; the digestive power is increased, the obesity reduced. Man becomes free of diseases and maintains the body in a healthy condition.”
It is similarly described in such books as the Gherand Samhita and the Shiva Samhita. In fact, the Shiva Samhita is more specific in praising this asana. It says: “A person who perfects this asana and does it daily induces vayu (vital or pranic energy) to flow through the back in the sushumna.”
There are various methods of performing paschimottanasana. Each method has its advantages, but the basic technique we will give has been chosen because we feel it allows maximum relaxation of the back; this in turn leads to the best possible stretch of the back in the final position. Some alternative methods are given at the end of this topic.