1. Institute of Sports Science and Clinical Biomechanics , University of Southern Denmark , Campusvej 55, 5230 Odense M , Denmark
2. Institute of Occupational Therapy, Physiotherapy and Radiography , Bergen University College , Bergen , Norway
3. Senior Citizen and Health Department, Social and Health Affairs , Municipality of Sonderborg , Ellegaardvej 25A, 6400 Sonderborg , Denmark
4. Department of Psychology , University of Southern Denmark , Campusvej 55, 5230 Odense M , Denmark