Prof. Dr. Felix Stief is the Director of the Function and Motion Lab at the Berufsgenossenschaftlichen Unfallklinik Frankfurt/Main in Germany. He started his professional career in the field of functional testing of sport shoes at the biomechanical laboratory of the company Adidas and obtained his PhD degree in biomechanics from the Technical University Munich. In 2010, he established the Movement Analysis Lab at the Department of Trauma Surgery and Orthopedics at the University Hospital Frankfurt/Main in Germany. Prof. Stief is the president of the German-Speaking Society for Clinical Gait Analysis (GAMMA). In 2024, he became a Professor of Musculoskeletal Biomechanics at the Medical Faculty of the Johann Wolfgang Goethe University Frankfurt/Main, where he also works as a lecturer in the field of clinical gait analysis and biomechanics. Prof. Stief's main research focus is in the field of instrumented 3D clinical movement analysis in children and adolescents, with orthopedic pathologies with an emphasis on degenerative joint disease and dynamic joint loading.