1. Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, Canada
2. Post Polio Clinic, University of British Columbia, Vancouver, Canada
3. Department of Health and Rehabilitation/Physiotherapy, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
4. Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden