1. Department of Physical Medicine and Rehabilitation; Central Finland Central Hospital; Jyväskylä Finland
2. Faculty of Sport and Health Sciences; University of Jyväskylä; Jyväskylä Finland
3. Department of Physics; University of Jyväskylä; Jyväskylä Finland
4. Department of General Practice and Primary Health Care; University of Helsinki; Helsinki Finland
5. Unit of Primary Health Care; Kuopio University Hospital; Kuopio Finland