Births, graduations, weddings, and funerals are all events around which the ingestion of food is a common denominator. But what happens when the ability to perform this seemingly safe act becomes a ruminative and dangerous activity? For the millions of individuals who experience difficulty swallowing each day, a biomechanical juxtaposition looms between swallowing safety and swallowing endangerment. Oropharyngeal dysphagia affects one in 25 individuals in the United States each year as a result of multiple medical diagnoses: stroke, head and neck cancer, neurodegenerative disorders, and gastroesophageal reflux disease (Bhattacharyya, 2014). Traditional treatment methods for the remediation of dysphagia include practice of swallow strengthening exercises, swallow maneuvers, pharyngeal stimulation techniques, diet consistency changes, and postural adjustments (Kiger, Brown, & Watkins, 2006). Non-traditional adjunctive treatments, such as surface electromyographic (sEMG)
biofeedback, have been more sporadically applied and underutilized due to lack of clinician training in swallowing application and decreased availability of equipment (Crary & Groher, 2000). Although principles of biofeedback have been used in physical therapy for over half a century to treat limb impairments and movement disorders (Giggins, Persson, & Caulfield, 2013), biofeedback’s emergence as a viable treatment option within the speech pathology discipline has been slower, spanning just a little more than the past two decades. Beginning with a case report by Bryant (1991) describing the positive outcome of biofeedback assisted dysphagia treatment in a patient exhibiting profound dysphagia, other researchers initiated a quest to formulate treatment protocols suitable for ameliorating swallowing dysfunction. The purpose of this investigation was to illuminate the impact of sEMG biofeedback on submental muscle activity during performance of the effortful swallow therapeutic technique.
An alternating treatment design was employed during this single subject research investigation to compare submental muscle peak amplitudes, demonstrating efficacy of visual biofeedback used with effortful swallow as compared to the use of the effortful swallow in the absence of visual feedback. Although conflicting outcomes on efficacy of sEMG biofeedback exist in current literature (Benfield, Everton, Bath, & England, 2018), the potential for positive therapeutic outcomes with the use of biofeedback-assisted dysphagia therapy is available. Results of this investigation revealed that data from three of four participants did not support the hypothesis that submental muscle peak amplitudes of effortful swallows performed with visual biofeedback were superior to effortful saliva swallows completed in the absence of visual biofeedback. Reasons for this finding are unknown, but could be attributed to participants mentally challenging themselves when performing effortful swallows in the blind. This data concurs with evidence reported by Benfield, Everton, Bath, and England (2018) that research supporting sEMG biofeedback in the treatment of dysphagia is inconclusive.
Keywords: surface electromyographic biofeedback, dysphagia, effortful swallow