1 Research Unit for Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense M, Denmark.
2 The Research Unit PROgrez, Department of Physiotherapy and Occupational Therapy, Næstved-Slagelse-Ringsted Hospitals, Region Zealand, Slagelse, Denmark.
3 Discipline of Public Health and Primary Care, Institute of Population Health, Trinity College Dublin, Russell Building, Tallaght Cross, Dublin, Ireland.