Tongue strengthening exercise is effective in improving the oropharyngeal muscles associated with swallowing in community-dwelling older adults in South Korea A randomized trial

Background Tongue strengthening exercise (TSE) is a remedial method for the training of swallowing-related muscles in the oropharyngeal phase. However, clinical evidence of its effectiveness is insufficient. Methods To investigate the effect of TSE on the oropharyngeal muscles associated with swallowing in older adults, in this study, 40 elder adults living in the community were recruited and assigned to 2 groups. The experimental group performed a TSE with a 1repetition maximum resistance level of 70%. The exercise was divided into an isometric and isotonic part. The control group did not perform an exercise. We measured the muscle strength and thickness of the tongue and suprahyoid muscles using an Iowa Oral Performance Instrument and ultrasonography. Results The experimental group showed a statistically significant increase in tongue muscle strength and thickness in the oral phase (P=.001 and <.001, respectively). In the pharyngeal phase, the experimental group showed a statistically significant increase in the mylohyoid and digastric muscles (suprahyoid muscles) (P=.045 and.019, respectively). The control group showed no statistically significant changes. Conclusion TSE is effective in increasing the strength and thickness of the oropharyngeal muscles of elder adults and is recommended for those who are vulnerable to swallowing difficulties.