1. Occupational Medicine, Department of Clinical & Experimental Medicine, University of Catania, Sicily, Italy
2. Anatomy & Histology, Department of Biomedical & Biotechnological Sciences, University of Catania, Sicily, Italy
3. Healhcare Management, P.O. Gaspare Rodolico, University Hospital of Catania, Sicily, Italy
4. Healhcare Management, P.O. Vittorio Emanuele, University Hospital of Catania, Sicily, Italy
5. Spinal Unit, Cannizzaro Hospital, Sicily, Italy