Described is a surgical instrument, such as an endoscopic instrument having at its distal end a working element such as a dissector, scissor or grasper, a shaft that defines a longitudinal axis of the instrument at a handle portion at the proximal end. The shaft rotates about the handle portion of the instrument. The endoscopic instrument also provides for angulation or articulation of the end effector with respect to the longitudinal axis of the shaft. The angulation is accomplished by providing two four bar linkage assemblies connecting the handle portion and the distal end portion of the instrument. A torsion bar provides support to the four bar linkage assembly and provides a lumen for accepting a control cable for actuating the working element.