Abstract: A seat or chair that includes a seat back that is moveable so that it may be positioned to provide primary support to the spine and surrounding tissue centered on the region between the 2nd lumbar vertebrae and the 11th thoracic vertebrae of a user of the chair. Support in this region assists the spine in maintaining a good posture, and may also partially support the weight of the spine above the lumbar region of the spine. Another aspect of the seat or chair comprises a seat or chair configuration that provides a selected degree of traction applied to the lumbar region of the spine when the user leans back in the seat or chair.