Abstract
The purpose of this study was to investigate the effects of different neck postures on the oral and pharyngeal stages of swallowing dynamics using non-invasive methods. Twenty-two healthy young adults were recruited as subjects, and four different neck postures were tested. The subjects swallowed 8 mL of water while electromyography (EMG) activity was recorded from the supraspinatus and orbicularis oris muscles using surface EMG. The time of the oral stage, EMG action potentials, and visual analogue scale scores were collected as outcomes. The results suggest that the flexed position suppresses the activity of swallowing-related muscles during the pharyngeal stage, on the other hand, it takes more time for the water to be pumped into the pharynx during the oral stage. The results also suggest the usefulness of using EMG to analyze the time from the start of orbicularis oculi muscle activity to the start of suprahyoid muscle activity as an indicator of the oral stage.
