A chair ergonomically designed to cause its occupant to assume a
sitting posture that acts to distribute the load imposed by the sitter's upper
body weight so as to relieve stress on the musculature of the lower back, thereby obviating lower
back pain. The seat of the chair is slidable along a track that is upwardly inclined at a
fixed angle relative to the structure on which the chair is supported. Hinged to the seat is a backrest that is supported at the rear of the chair. When an individual sits down to place his
buttocks on the seat, he then slides the seat along the track until the backrest assumes an angle with respect to the seat at which it is comfortable to the sitter, and the seat is then latched to maintain this orientation. The
resultant sitting posture of the individual is such that the load imposed by his upper
body weight is to a substantial degree transferred away from the ischeal tuberosities and toward the lower back, where the weight is borne by the vertebral spinous processes, and to the thighs. Additionally, the iliopsosas and other musculature that normally maintains support when standing but is stressed when sitting in a conventional chair or bench is not stressed.