EFFECTS OF GRAVITY ON VELOPHARYNGEAL MUSCLE-ACTIVITY DURING SPEECH

Assessment of the role of gravitational forces in the motor control of the velopharyngeal mechanism was the focus of this study, Specificall y, the effect of gravity on activation levels of the levator veli pala tini and palatoglossus muscles was assessed, Nineteen volunteers repea ted a CV syllable in upright and supine body positions. Overall, lower peak activation levels of levator veli palatini were observed in the supine body position. The results suggest that less muscle activity wa s seen in the levator veli palatini in the supine body posture, where gravitational effects worked in the same direction (i.e., toward closu re), No statistically significant group effects were seen in muscle ac tivation levels of palatoglossus across the two body postures, althoug h clear gravity effects were observed in some subjects, The implicatio ns of these findings from a speech motor control perspective are discu ssed in relation to normal and disordered velopharyngeal function.