We investigate the feedforward modulation methodology of the dynamic behaviour of anthropomorphic systems which inherently possess abundant actuators. For the complete modulation of the dynamic behaviour of such systems, redundant actuation is essential since it enables the system to modulate the stiffness property or weighted stiffness property such as motion frequency, and even in the modulation of the damping ratio of the system, the stiffness property plays an important role. We also address that incorporation of active damper is necessary for complete modulation of the dynamic behaviour. The feasibility of our proposed scheme is verified through simulation for a two degree-of-freedom anthropomorphic robot resembling the human upper-extremity.