Chair yoga is not related to the couch yoga described in my story.
Chair yoga is yoga designed for those who, for whatever reason, are unable to participate in traditional standing yoga. Sitting allows those who are severely limited in physical strength the ability to practice yoga. Whether strictly for the physical benefits, or as a spiritual practice, or both. This makes chair yoga perfect for elders who have a limited range of motion or those with injuries that preclude the usual standing, bending and other more demanding movements and positions required in a typical yoga class.
All that being said, my friend and colleague Marsha Meyer is pioneering (Vinyasa) mat and chair yoga in Brooklyn. Take a look at her Web site, Responsive Yoga, or contact her at firstname.lastname@example.org with any questions. She is offering private individual or group instruction and teaching classes around town at a studio near you.