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.