About the Authors

Rob C. van Lummel

r.vanlummel@mcroberts.nl

Affiliations McRoberts BV, The Hague, The Netherlands, MOVE Research Institute Amsterdam, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands

Stefan Walgaard

Affiliation McRoberts BV, The Hague, The Netherlands

Markus A. Hobert

Affiliations Center for Neurology and Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, University of Tuebingen, Tuebingen, Germany, DZNE, German Center for Neurodegenerative Diseases, Tuebingen, Germany

Walter Maetzler

Affiliations Center for Neurology and Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, University of Tuebingen, Tuebingen, Germany, DZNE, German Center for Neurodegenerative Diseases, Tuebingen, Germany

Jaap H. van Dieën

Affiliation MOVE Research Institute Amsterdam, Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands

Francisca Galindo-Garre

Affiliation Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Centre, Amsterdam, The Netherlands

Caroline B. Terwee

Affiliation Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Centre, Amsterdam, The Netherlands

Competing Interests

RVL is a PhD student at the VU University Amsterdam and director of McRoberts and SW is an employee of McRoberts. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: RVL MH WM CBT. Performed the experiments: RVL SW MH. Analyzed the data: RVL SW FG CBT. Contributed reagents/materials/analysis tools: SW JVD FG CBT. Wrote the paper: RVL JVD CBT.