Abstract: An armrest that is infinitely adjustable is provided by the combination of a pin and slot arrangement for adjusting the arm in one direction and a second pin and slot arrangement for angularly adjusting the arm in a different direction, the second pin being in the form of a locking cam which locks the arm to a portion of the chair.

Abstract: 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.