The Effect of 4-channel Neuromuscular Electrical Stimulation on Swallowing Kinematics and Pressures: A Pilot Study Objective The purpose of this study was to evaluate the effectiveness of the sequential 4-channel neuromuscular electrical stimulation (NMES) system. Design As a prospective case-control study, ten healthy subjects and ten patients with dysphagia were prospectively enrolled. Swallowing with and without sequential 4-channel NMES (suprahyoid, infrahyoid muscles) was evaluated via videofluoroscopic swallowing study (VFSS) and high-resolution manometry (HRM). Results Results showed that the sequential 4-channel NMES significantly improved the videofluoroscopic dysphagia scale (VDS) during thick-fluid swallowing in patients with dysphagia. Furthermore, the kinematic analysis of VFSS showed a tendency that NMES reduced duration of hyoid bone movement during thin- or thick-fluid swallowing. The HRM parameters –maximal pressure of velopharynx (VP), tongue base (TB), cricopharyngeal pressure (CP), minimal upper esophageal sphincter (UES) pressure, area of VP, UES activity time, and duration of nadir UES – during thin-fluid swallowing were significantly improve in both groups compared with the HRM parameters without NMES. Conclusion The sequential 4-channel NMES may help improve the parameters of VFSS, kinematic analysis of the hyoid bone movement, and HRM during swallowing. Further investigations are needed to better examine the effects of NMES in patients with dysphagia. Donghwi Park and Jee Hyun Suh contributed equally to this paper and should therefore be regarded as equivalent first authors. Address corresponding author: Ju Seok Ryu, M.D., Ph.D. Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 82 Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, South Korea, 463-707 (e-mail: jseok337@snu.ac.kr), Tel : 82-31-787-7739, Fax : 82-31-787-4051 Acknowledgement: The authors gratefully appreciate MRCC team of Seoul National University Bundang Hospital for their work in the area of statistics in this study Financial support: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2016R1D1A1B03935130) Conflict of interest: No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.