title: The Sequence of Swallowing Events During the Chin-Down Posture.
abstract: OBJECTIVE
  This study investigated the effect of the chin-down posture on the sequence of swallowing events in healthy adults.
  
  
  METHODS
  Sixteen healthy participants performed 45 5-ml thin liquid swallows during videofluoroscopy: 5 neutral head position, 30 chin-down posture, and then 10 neutral head position. Eight swallowing events were measured: the time of hyoid burst, bolus head in the pharynx, bolus tail in the pharynx, laryngeal vestibule closure (LVC), upper esophageal sphincter (UES) opening, bolus head in the UES, bolus tail exiting the pharynx, and laryngeal vestibule opening (LVO).
  
  
  RESULTS
  Our key finding is that LVC was one of the first 3 swallowing events in 69% of neutral swallows and in 78% of chin-down swallows (p = .006). Also, LVO occurred last in 14% of chin-down swallows but never occurred last in the preceding neutral swallows (p ≤ .001). Thus, in chin-down swallows, LVC occurred earlier and LVO occurred later.
  
  
  CONCLUSIONS
  The chin-down posture may be beneficial for individuals with delayed onset of LVC and reduced duration of the LVC. Future studies are needed to examine this effect in individuals with dysphagia.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Young
authors.forename: Phoebe
authors.initials: P
authors.lastname: Macrae
authors.forename: Cheryl
authors.initials: C
authors.lastname: Anderson
authors.forename: Isha
authors.initials: I
authors.lastname: Taylor-Kamara
authors.forename: Ianessa A
authors.initials: IA
authors.lastname: Humbert
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003679:Deglutition / Q000502:physiology*; D004326:Drinking / Q000502:physiology*; D049631:Esophageal Sphincter, Upper / Q000502:physiology; D005260:Female; D005471:Fluoroscopy; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D007830:Larynx / Q000502:physiology; D008297:Male; D010614:Pharynx / Q000502:physiology; D011187:Posture / Q000502:physiology*; D012016:Reference Values; D014741:Video Recording; D055815:Young Adult