1. Department of Community Medicine and Rehabilitation, Physiotherapy , Umeå University , Umeå , Sweden
2. Pain and Rehabilitation Centre and Department of Medical and Health Sciences , Linköping University , Linköping , Sweden
3. Department of Medical and Health Sciences, Faculty of Medical and Health Sciences , Linköping University , Linköping , Sweden
4. Department of Community Medicine and Rehabilitation, Rehabilitation Medicine , Umeå University , Umeå , Sweden