1 Department of Rehabilitation Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo, Tokyo 113-8421, Japan.
2 Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 173-82 Gumi-Ro, Bundang-Gu, Seongnam 13620, Republic of Korea.
3 BDH-Klinik Greifswald, Centre for Neurorehabilitation, Intensive Care, and Spinal Cord Injury Unit, Universität Greifswald, Karl-Liebknecht-Ring 26a, 17491 Greifswald, Germany.