1 Clinical and Experimental Sciences Department, University of Brescia, Brescia, Italy; Don Gnocchi Foundation, Milan, Italy. Electronic address: stefano.negrini@unibs.it.
2 Department of Physical and Rehabilitation Medicine, University Hospitals Leuven, Leuven, Belgium.
3 University of Otago, Dunedin, New Zealand.
4 Department of Rheumatology, Physical Medicine and Rehabilitation, School of Medicine, University of Zagreb, University Hospital Center "Sestre Milosrdnice", Zagreb, Croatia.
5 Department of Mental and Physical Health and Preventive Medicine, Second University of Naples, Naples, Italy.
6 Department of Physical and Rehabilitation Medicine, Medical University of Plovdiv, Bulgaria; University Hospital "Sv. Georgi", Plovdiv, Bulgaria.
7 Integrative Rehabilitation Research Unit, Institute for Epidemiology, Social Medicine and Health Systems Research, Hannover Medical School, Hannover, Germany.