Karl Fannar Gunnarsson, PhD, BCBA-D, is an Assistant Professor in the Department of Physical Therapy at the University of Iceland and Adjunct Professor at Brock University, Canada. He also serves as a Project Manager at Landspítali – The National University Hospital of Iceland. His research focuses on behavior analysis, neurorehabilitation, and health sciences, with ongoing projects in traumatic brain injury, prosthetics, staff training in clinical settings, and clinical procedural integrity. He is certified as a clinical behavior analyst (SATÍS/ICE-ABA) and is actively engaged in advancing evidence-based practice and interdisciplinary education.