1. Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden
2. Department of Clinical Sciences, Paediatrics, Umeå University, Umeå, Sweden
3. Department of Public Health and Clinical Medicine/Rheumatology, Umeå University, Umeå, Sweden
4. Department of Computing Science, Umeå University, Umeå, Sweden