A load balancing arm for a medical device support system includes a proximal hub, a support arm, a link, and a distal end vertical block. The components together may form a four bar linkage. The proximal hub is configured for pivotable movement about an axis P-P. The distal hub is configured to support a medical device load for pivotable movement about an axis D-D. The distal hub is mounted to the distal end vertical block for pivotable movement between a first position in which the axis D-D is at a first angle relative to the axis P-P and a second position in which the axis D-D is at a second angle relative to the axis P-P, wherein the first angle is different than the second angle. A parallelism adjustment mechanism enables the axis D-D to be adjusted so as to be substantially parallel to the axis P-P.