Chair back with lumbar and pelvic supports

An office chair (10) is provided having a back assembly (24) which is configured to provide supplemental support to the back of a chair occupant in addition to the support provided by the primary support surface (31) of the chair back. The chair back includes a lumbar support unit (28) having a lumbar support pad (91) wherein asymmetric support is provided to the left and right halves of the lumbar pad (91). As such, the asymmetric support loads are independently adjustable to more comfortably support a chair occupant. The chair back also includes a pelvic support pad (29) which is disposed vertically adjacent to the lumbar support (28). 提供种办公室座椅（10），除了由座椅靠背的主支承表面（31）提供的支承之外，具有构造成为座椅乘坐者的后背提供补充支承的靠背组件（24）。座椅靠背包括具有腰部支承垫（91）的腰部支承单元（28），其中不对称的支承提供给腰部垫（91）的左和右半件上。因此，独立调节不对称的支承负载，以便更加舒适地支承座椅乘坐者。座椅靠背还包括靠近腰部支承（28）垂直布置的骨盆支承垫（29）。