  Similarly to humans, humanoid robots require posture control and balance to
walk and interact with the environment. In this work posture control in
perturbed conditions is evaluated as a performance test for humanoid control. A
specific performance indicator is proposed: the score is based on the
comparison between the body sway of the tested humanoid standing on a moving
surface and the sway produced by healthy subjects performing the same
experiment. This approach is here oriented to the evaluation of a
human-likeness. The measure is tested using a humanoid robot in order to
demonstrate a typical usage of the proposed evaluation scheme and an example of
how to improve robot control on the basis of such a performance indicator score
