The opening of the āsana chapter defines posture through the classical formula: sthira-sukham āsanam (Patañjali Yoga Sūtra II.46). Steady (sthira) and comfortable (sukha) — not forced, not strained.

The purpose of āsana according to Gheraṇḍa is haṭha-saṃśuddhi — purification of the dual energy system (solar and lunar, prāṇa and apāna). Postures prepare the energy channels.

Doṣa-vināśana connects āsana with Ayurvedic medicine. These are not merely physical exercises but techniques for elemental balance.