Klaas is a Physiotherapist and Orthopaedic Manipulative Therapist from the Netherlands. After graduating from a Bachelor of Physiotherapy at the University of Utrecht in 1999, Klaas started working as a Physio in a private practice in Amsterdam. In order to develop more evidence based background Klaas went on studying at the Catholic University of Leuven to graduate in 2002 from Master of Science in Physiotherapy. In the mean time he had started his own private practice in Amsterdam in 2000. Driven by the ambition to have expert skills in treating musculoskeletal patients, Klaas started studying Orthopaedic Manipulative Therapy in 2002. He successfully completed this specialisation in 2007.