A.  Bicchi, Bosio, L., Dario, P., Guiggiani, M., Manfredi, E., and Pinotti, P. C., ?Leg-Ankle-Foot System for Investigating Sensor Based Legged Locomotion?, in Proc. IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, Tsukuba, Japan, 1989 [Online]. Available: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=637970