Swooshi - The frame acts as a spring, as it flexes, allows the wheel to roll forward and back, ultimately becoming a naturally interactive rocking chair.
This design has limited motion, only allowing for moderate flexibility in the chair's main spine. Rather than feet grating against the floor, the front feet are static, as the rear wheel rolls gently- you have a smooth "Swoosh" of motion both forward and back as you relax in the chair, similar yet beyond what you would experience in a rocking chair.