1. Department of Experimental Medicine, Section of Human Physiology, University of Genoa, 16146 Genoa;
2. Fondazione Don C. Gnocchi, 54037 Marina di Massa; and
3. Groupe Analyse du Mouvement, University of Bourgogne, 21078 Dijon, France
4. Physiological Institute, University of Pavia, and Fondazione Salvatore Maugeri, Institute of Care and Research, 27100 Pavia, Italy; and