Date on Master's Thesis/Doctoral Dissertation


Document Type

Master's Thesis

Degree Name



Communicative Disorders

Degree Program

Communicative Disorders, MS

Committee Chair

Pitts, Teresa

Committee Co-Chair (if applicable)

Mattingly, Rhonda

Committee Member

Mattingly, Rhonda

Committee Member

Smith, Alan

Author's Keywords

swallow; dysphagia


During swallow, a negative esophageal pressure is present that, along positive pressure from the tongue, which works to move the bolus through the pharynx into the esophagus. This negative esophageal pressure is thought to be produced via recruitment of chest wall inspiratory muscles (diaphragm and parasternal). This current study aimed to examine respiratory muscle recruitment across behaviors which have known inspiratory muscle activity (eupnea, augmented breath and cough) and compare to swallow. It was hypothesized that there would be no significant difference in amplitude and muscle recruitment over 75 ms between swallow and eupnea, but cough and augmented breath would be significantly larger. Electromyograms (EMG) from the costal diaphragm and parasternal muscles were recorded and analyzed in five freely breathing anesthetized cats. Muscle recruitment was examined by taking both the root mean square over the initial 75 ms (RMS75) of each behavior and the maximum amplitude of muscle activity for the total duration of the behavior. Results found that there was a significant difference for maximum amplitude of muscle activation across all behaviors for the parasternal and for augmented breath and cough for the diaphragm. Muscle recruitment of parasternal was significantly different from swallow for the behavior of eupnea. These results, along with a growing body of evidence, provide credence to the theory that inspiratory muscle activity is part of the swallow central pattern generator. This work could provide needed clinical information for the evaluation of dysphagia in at-risk patients.