A. Ajoudani, Gabiccini, M., Tsagarakis, N. G., Albu-Schaeffer, A., and Bicchi, A., ?Tele-Impedance: Exploring the Role of Common-Mode and Configuration-Dependant Stiffness?, in IEEE-RAS International Conference on Humanoid Robots, Osaka, Japan, 2012, pp. 363-369.