(Suṣumṇā Nāḍī): The “most gracious energy channel.” It is the neutral energy channel that passes through the spine in the subtle body. It begins in muladhara chakra and goes along the middle of the subtle spine to brahmarandhra (the “Brahmic aperture”) at the crown of the head. It is the expression of perfect balance and neutrality between ida nadi and pingala nadi, the polar aspects of our being. Bringing ida and pingala into equilibrium means the absorption of the energy in sushumna, which represents a major focus of Hatha Yoga.