1. EDRS - Robotics, Control and Intelligent Systems, EPFL, Lausanne, Switzerland
2. The Pennsylvania State University, Department of Kinesiology, University Park, PA, USA
3. Swiss Center for Electronics and Microtechnology, Neuchatel, Switzerland
4. IMT LAI, EPFL, Neuchatel 2, Switzerland
5. IMT, EPFL, Neuchatel 2, Switzerland