1Department of Mathematics “F. Enriques”, Via C. Saldini, 50 - 20133 Milan, Italy
2Department of Mechanical and Aerospace Engineering, ‘Sapienza’ University of Rome, Via Eudossiana 18 - 00184 Rome, Italy
3ISS- Department of Technology and Health, V.le Regina Elena, 299 - 00161 Rome, Italy
4Orthopedy and Traumatology Area,‘Campus Bio-Medico’ University, Via Alvaro del Portillo, 200 - 00128 Rome, Italy