The Influence of Surface Electromyography Visual and Clinician Verbal Feedback on Swallow Effort Ratio at Different Bolus Volumes in a Healthy Population

Effect of Visual Biofeedback Obtained Using the Iowa Oral Performance Instrument on the Suprahyoid Muscle Activation Level During Effortful Swallowing Maneuver

Effortful swallowing (ES) is a maneuver prescribed for patients who experience pharyngeal residues after swallowing owing to weakness of the tongue and pharyngeal constrictor muscles. ES can increase the pharyngeal contraction force by intentionally increasing the degree of effort during swallowing. However, the effect is limited as the nature of swallowing makes it difficult to maintain a constant high-effort level. The aim of this study was to assess the effect of visual feedback, delivered by the Iowa Oral Performance Instrument (IOPI), a tongue pressure measurement device on ES maneuver effort. Overall, 34 healthy adults performed five sets of ten ES, once every 10 s. The ES maneuver was conducted under two conditions, ES with and without IOPI biofeedback in a crossover design. IOPI biofeedback was provided at 80% of the maximum posterior oral tongue pressure. The suprahyoid muscle activation level was assessed using surface electromyography during the ES maneuver. The mean suprahyoid muscle activation levels in all sets for which IOPI biofeedback was provided were significantly higher than those during ES maneuver without biofeedback (p < 0.05). IOPI biofeedback can help maintain the ES maneuver target effort, utilizing a constantly high swallowing pressure potentially promoting better pharyngeal pressures and muscle strength.