A modular standing frame comprising: a chair module and at least one other module capable of being coupled with the chair module and selected from the group consisting of a glider module , a workstation module , and a mobility module , wherein the chair module further comprises: a support member having hingedly connected thereto at a hinge a lower seat frame having a secondary hip plate extending upward therefrom, wherein the lower seat frame comprises a seat ; an upper seat frame with a seat back ; an extensor mechanism coupled between the support member and the lower seat frame , the extensor mechanism being constructed and arranged to rotate the lower seat frame between a lower, seated posture and an upper, standing posture; an adjustment member coupled between the support member and the upper seat frame , the adjustment member being extendable and retractable to control the angle of the upper seat frame with respect to the lower seat frame ; the support member , lower seat frame , upper seat frame , and adjustment member forming a four-bar linkage that ensures that the upper seat frame retains its angular orientation with respect to a reference surface in its seated posture, its standing posture, and in transition therebetween; and an armature ; and a work surface coupled to a free end of the armature ; characterized in that the upper seat frame has a hip plate extending forward therefrom, the hip plate and the secondary hip plate rotatively coupling the upper seat frame to the lower seat frame at a joint, and in that the armature is coupled to the hip plate of the chair module , the armature and work surface moving with the upper seat frame and maintaining their angular orientation with respect to the reference surface. a support member having hingedly connected thereto at a hinge a lower seat frame having a secondary hip plate extending upward therefrom, wherein the lower seat frame comprises a seat ; an upper seat frame with a seat back ; an extensor mechanism coupled between the support member and the lower seat frame , the extensor mechanism being constructed and arranged to rotate the lower seat frame between a lower, seated posture and an upper, standing posture; an adjustment member coupled between the support member and the upper seat frame , the adjustment member being extendable and retractable to control the angle of the upper seat frame with respect to the lower seat frame ; the support member , lower seat frame , upper seat frame , and adjustment member forming a four-bar linkage that ensures that the upper seat frame retains its angular orientation with respect to a reference surface in its seated posture, its standing posture, and in transition therebetween; and an armature ; and a work surface coupled to a free end of the armature ; characterized in that the upper seat frame has a hip plate extending forward therefrom, the hip plate and the secondary hip plate rotatively coupling the upper seat frame to the lower seat frame at a joint, and in that the armature is coupled to the hip plate of the chair module , the armature and work surface moving with the upper seat frame and maintaining their angular orientation with respect to the reference surface. <EOS>