1. Ecole Centrale de Nantes, AAU, UMR CNRS 1563, Nantes, France
2. IMT Atlantique, Lab-STICC, UMR CNRS 6285, Brest, France
3. Physical and Rehabilitation Medecine Unit, University Hospital of Rennes, Rennes, France
4. Inria (Univ. Rennes, CNRS, IRISA), Campus de Beaulieu, Rennes, France