2006 Volume 10 Issue 1 Pages 12-21
【Purpose】This study was aimed to electromyographically examine whether the palatoglossus (PG) muscle might be involved in regulation system of transporting Newtonian liquid around the transition from the oral to the pharyngeal phases．That is，it was examined whether there might be change in PG muscle activity in relation to liquid volume during swallowing．
【Methods】Seven normal adults participated in this study．Each subject was instructed to swallow liquid of five different volumes； 12.5％，25％，50％，100％ and 150％ (or 125％) of optimum volume for swallowing，which was determined individually for each subject prior to this study．Smoothed EMG signals of PG muscle activity and levator veli palatini (LVP) muscle activity were studied in terms of swallowing volume．
【Results】PG muscle waveform for one single swallow showed two patterns of the activity；One was a pattern of a single peak and the other was of two peaks．The peak of the single peak pattern and the second peak of the two peak pattern were considered as the same．There was marked aspect of change in PG muscle activity at the timing of those peaks in relation to change in swallowing volume．That is，for three subjects，PG muscle activity was significantly correlated with swallowing volume while PG muscle activity was ranged in relatively higher region for remaining four subjects．The PG muscle could be involved in the regulation of swallowing at the transition of bolus from the oral to the pharyngeal phases．
