After working in a physical therapy clinical practice Jan started a manual therapy practice in 1983 and moved on into part-time education in 1984. In 1989 he was appointed as a member of the board of the Dutch Association of Manual Therapy (NVMT). His mean interest was education and scientific development of manual therapy. In 1994 he was involved in a randomized clinical trial on neck pain at the VU University medical center in Amsterdam. In that time he finished a MSc in epidemiology. As a result he started a new RCT and wrote a PhD thesis regarding Neck Pain and completed his PhD in 2007 at the VU University.
Jan is currently program coordinator Master Manual Therapy at the University of Applied Science, Hogeschool Utrecht in the Netherlands. This programme is an approved route leading to membership of the Dutch Member Organisation of IFOMT, the Dutch Association of Manual Therapy (NVMT). Furthermore he is working part-time in a clinical practice, Medical Centre IMPACT, in Zoetermeer the Netherlands.
Jan's research is focused on two aspects. Clinimetrics; validity, reproducibility, responsiveness and feasibility of measurements instruments, and the efficacy and effectiveness of manual therapy management in Neck Disorders. On both subjects he is still lecturing nationally and internationally, giving courses or presentations.
In addition to being Member of the Standards Committee for IFOMT since 1995, Jan organized several congresses on manual therapy in the Netherlands and was Chair of the Scientific Committee of the IFOMT congres 2008 in Rotterdam, the Netherlands.