1. Department of Plastic Surgery University of Groningen, University Medical Center Groningen Groningen the Netherlands
2. Department of Epidemiology University of Groningen, University Medical Center Groningen Groningen the Netherlands
3. Department of Neurosurgery University of Groningen, University Medical Center Groningen Groningen the Netherlands
4. Center for Rehabilitation University of Groningen, University Medical Center Groningen Groningen the Netherlands
5. Sirindhorn School of Prosthetics and Orthotics Faculty of Medicine Siriraj Hospital, Mahidol University Bangkok Thailand