Submental sEMG and Hyoid Movement During Mendelsohn Maneuver, Effortful Swallow, and Expiratory Muscle Strength Training

Purpose: This study investigated the concurrent biomechanical and electromyographic properties of 2 swallow-specific tasks (effortful swallow and Mendelsohn maneuver) and 1 swallow-nonspecific (expiratory muscle strength training [EMST]) swallow therapy task in order to examine the differential effects of each on hyoid motion and associated submental activation in healthy adults, with the overall goal of characterizing task-specific and overload properties of each task. Method: Twenty-five healthymale and female adults (M=25 years of age) participated in this prospective, experimental study with 1 participant group. Each participant completed all study tasks (including normal swallow, Mendelsohn maneuver swallow, effortful swallow, and EMST task) in random order during concurrent videofluoroscopy and surface electromyography recording. Results: Results revealed significant differences in the trajectory of hyoid motion as measured by overall displacement and angle of elevation of the hyoid bone. As well, timing of hyoid movement and amplitude differences existed between tasks with regard to the activation of the submental musculature. dConclusions: Study results demonstrated differential effects of the 3 experimental tasks on the principles of task specificity and overload. These principles are important in the development of effective rehabilitative programs. Subsequent direction for future research is suggested.