Effects of oropharyngeal exercises on the swallowing mechanism of older adults: A systematic review.

ABSTRACT

PURPOSE: Age-related changes to the swallowing mechanism, or presbyphagia, may put older adults at a higher risk for developing diseases and dysphagia. Maintaining swallowing functions could help prevent frailty and facilitate healthy ageing. This review summarises and appraises the effects of oropharyngeal exercises on the swallowing functions of healthy older adults without dysphagia. It is hypothesised that these exercises will strengthen and improve the structures and functions of the normal ageing swallow. METHOD: This review was reported according to the PRISMA 2020 guidelines. Five electronic databases (Medline, Embase, Cochrane Library, Web of Science, CINAHL) and Google Scholar were searched in June 2021. A rerun was done in January 2023. Study selection, data extraction, and quality assessment were done by two independent raters. RESULT: A total of 23 studies were reviewed. Meta-analysis was not conducted due to the heterogenous training protocols and outcomes. Majority (n = 21) had fair quality due to incomplete reporting. Exercises targeting oral structures were implemented the most (n = 15), followed by variations of the head lift (n = 4), and effortful swallow exercise (n = 1). Others implemented combined or multiapproach exercise studies (n = 3). Apart from surface electromyography findings, statistically significant improvements in oral and pharyngeal phase swallowing outcomes such as increased lingual isometric and swallowing pressures, bite force, muscle thickness, hyolaryngeal excursion, and upper oesophageal sphincter opening diameter were reported in 95% of the studies (n = 22). CONCLUSION: Collective evidence suggests that strength training for swallowing-related structures leads to increases in structural strength, endurance, and muscle mass. The effects of exercises on overall swallowing efficiency and safety remain unclear. Results should be interpreted with caution due to methodological limitations. Further research should examine the long-term effects of these exercises in preventing frailty and reducing the burden of dysphagia in older adults.