title: Different Movement of Hyolaryngeal Structures by Various Application of Electrical Stimulation in Normal Individuals.
abstract: OBJECTIVE
  To identify the differences in the movement of the hyoid bone and the vocal cord with and without electrical stimulation in normal subjects.
  
  
  METHODS
  Two-dimensional motion analysis using a videofluoroscopic swallowing study with and without electrical stimulation was performed. Surface electrical stimulation was applied during swallowing using electrodes placed at three different locations on each subject. All subjects were analyzed three times using the following electrode placements: with one pair of electrodes on the suprahyoid muscles and a second pair on the infrahyoid muscles (SI); with placement of the electrode pairs on only the infrahyoid muscles (IO); and with the electrode pairs placed vertically on the suprahyoid and infrahyoid muscles (SIV).
  
  
  RESULTS
  The main outcomes of this study demonstrated an initial downward displacement as well as different movements of the hyoid bone with the three electrode placements used for electrical stimulation. The initial positions of the hyoid bone with the SI and IO placements resulted in an inferior and anterior displaced position. During swallowing, the hyoid bone moved in a more superior and less anterior direction, resulting in almost the same peak position compared with no electrical stimulation.
  
  
  CONCLUSIONS
  These results demonstrate that electrical stimulation caused an initial depression of the hyoid bone, which had nearly the same peak position during swallowing. Electrical stimulation during swallowing was not dependent on the position of the electrode on the neck, such as on the infrahyoid or on both the suprahyoid and infrahyoid muscles.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Kosin University College of Medicine, Busan, Korea.
authors.forename: Sae Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Physical Medicine and Rehabilitation, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Byung-Mo
authors.initials: BM
authors.lastname: Oh
authors.affiliation: Department of Physical Medicine and Rehabilitation, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Tae Ryun
authors.initials: TR
authors.lastname: Han
authors.affiliation: Department of Physical Medicine and Rehabilitation, Kosin University College of Medicine, Busan, Korea.
authors.forename: Ho Joong
authors.initials: HJ
authors.lastname: Jeong
authors.affiliation: Department of Physical Medicine and Rehabilitation, Kosin University College of Medicine, Busan, Korea.
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Sim
keywords: Deglutition; Dysphagia; Hyoid bone; Neck muscles