Graduate Studies


First Advisor

Steven M. Barlow

Date of this Version

Spring 5-2019

Document Type



A Thesis Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Speech-Language Pathology and Audiology, Under the Supervision of Professor Steven Barlow. Lincoln, Nebraska: May, 2019

Copyright 2019 Michaela Kathleen Sullivan,


In an effort to further the understanding of fine motor control in the lips, this study measured isometric ramp-and-hold force dynamics at the oral angles in neurotypical young adults (24 females/22 males) examining the independent variables of oral angle side (L/R), handedness, age, and sex. Force dynamics were measured with a wireless data acquisition system and force sensors (ForceWIN10). During the visuomotor task, participants completed randomized blocks of isometric ramp-and-hold trials at 4 target levels (0.25, 0.5, 1, and 2 Newtons) presented via a 15-inch computer monitor. Patients were encouraged to meet and hold the line “as rapidly and accurately as possible”. A maximum voluntary contraction force task was also completed. Significant interactions between force target and muscle group were found in the dependent variables of peak force, mean force, criterion hold percentage, and maximum voluntary contraction force. A significant relationship was indicated between biological sex and maximum voluntary contraction force (means: F = 3.99 N, M = 5.53 N). A slight statistically significant advantage for the L-oral angle during T2 of the criterion hold percentage was identified for left-handed individuals, though the number of those participants (n = 5) limits the reliability of the measure. Target force level was significant for dF/dtmax and reaction time. In addition, 35% of the participants were identified to have a dominant side of their face, though it did not correlate with handedness.

Advisor: Steven M. Barlow

Results.xlsx (193 kB)