Postural Effects on Normal Oropharyngeal Swallowing: Videofluoroscopic Swallow Study (VFSS)

Background: There is considerable amount of research assessing the effect of posture (supine and upright) on swallowing. However, there are no previous studies that assess the difference between sitting and standing positions and their effect on swallowing. Aim: To assess the physiological difference between standing and sitting positions in oropharyngeal phase of swallowing. Patients and Methods: Dynamic videofluoroscopic swallow studies were performed on 30 healthy adult volunteers (15 males and 15 females) ranging in age from 18 to 45 years. All volunteers were examined in sitting and standing positions with a lateral view using barium sulfate. Oral Transit Time and Pharyngeal Transit Time are measured. In addition, hyoid peak elevation is calculated. Results: During studying fluid bolus, there was significant difference between sitting and standing positions in Pharyngeal Transit Time (P value=0.005). On the other hand, there was no significant difference between sitting & standing positions in Oral Transit Time. Conclusion: Although the PTT was longer in the sitting position with a statistically significant difference with the standing position, it did not affect the hyoid peak elevation. Hence, the body position affected the duration of PTT without affecting the degree of displacement of the hyoid bone.