title: The accuracy of the swallowing kinematic analysis at various movement velocities of the hyoid and epiglottis.
abstract: OBJECTIVE
  To evaluate the accuracy of the swallowing kinematic analysis.
  
  
  METHODS
  To evaluate the accuracy at various velocities of movement, we developed an instrumental model of linear and rotational movement, representing the physiologic movement of the hyoid and epiglottis, respectively. A still image of 8 objects was also used for measuring the length of the objects as a basic screening, and 18 movie files of the instrumental model, taken from videofluoroscopy with different velocities. The images and movie files were digitized and analyzed by an experienced examiner, who was blinded to the study.
  
  
  RESULTS
  The Pearson correlation coefficients between the measured and instrumental reference values were over 0.99 (p<0.001) for all of the analyses. Bland-Altman plots showed narrow ranges of the 95% confidence interval of agreement between the measured and reference values as follows: 0.14 to 0.94 mm for distances in a still image, -0.14 to 1.09 mm/s for linear velocities, and -1.02 to 3.81 degree/s for angular velocities.
  
  
  CONCLUSIONS
  Our findings demonstrate that the distance and velocity measurements obtained by swallowing kinematic analysis are highly valid in a wide range of movement velocity.
authors.affiliation: Department of Rehabilitation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung Hak
authors.initials: SH
authors.lastname: Lee
authors.forename: Byung-Mo
authors.initials: BM
authors.lastname: Oh
authors.forename: Seong Min
authors.initials: SM
authors.lastname: Chun
authors.forename: Jung Chan
authors.initials: JC
authors.lastname: Lee
authors.forename: Yusun
authors.initials: Y
authors.lastname: Min
authors.forename: Sang-Heum
authors.initials: SH
authors.lastname: Bang
authors.forename: Hee Chan
authors.initials: HC
authors.lastname: Kim
authors.forename: Tai Ryoon
authors.initials: TR
authors.lastname: Han
keywords: Biomechanics; Deglutition; Reproducibility of results