Martin van der Esch, PhD is a physiotherapist, scientific senior researcher (clinical epidemiologist) and senior teacher. He has done research in the field of knee osteoarthritis (OA) since 2001, particularly knee instability in relation to muscle strength and activity limitations. Since 2008, he is coordinator of the Amsterdam OA Cohort study in Reade, Centre of Rheumatology and Rehabilitation in Amsterdam, the Netherlands. He is experienced in conducting epidemiological and biomechanical studies in patients with knee- and/or hip OA. He is also an experienced senior teacher at the School of Physiotherapy, Amsterdam University of applied health sciences, Amsterdam, the Netherlands.