Expiratory muscle training improves pharyngeal muscles and swallowing function in patients with dysphagia

Background: Expiratory muscle training (EMT) is effective for improving coughing and swallowing function in dysphagia patients. However, the effect of EMT on the muscle contraction of the pharynx is unclear. We hypothesized that EMT would influence pharyngeal muscle contraction, and evaluated the morphological change of these muscles using endoscopy. Methods: Twelve patients with dysphagia (11 male, mean age 72.1 years) were randomly assigned to the EMT group or control group. In the EMT group, the patients performed 25 breaths at 75% of the maximum expiratory pressure for 4 weeks with the EMT device. In both groups, pharyngeal dynamics during expiratory muscle loading were evaluated by laryngoscope at baseline and 4 weeks later. Results: After 4 weeks, EMT significantly increased magnitude of the change of the lateral (17.1 ± 11.1 to 28.4 ± 16.3%, p=0.003) and longitudinal diameter (29.9 ± 18.6 to 56.5 ± 6.7%, p=0.015) of the pharynx, but no significant change in the control group. EMT significantly improved in repetitive saliva swallowing test (3.3 ± 2.3 to 4.4 ± 2.4 times/30sec, p=0.011). And EMT improved significantly in VC, FEV1, peak flow, and MEP (p Conclusion: These findings suggest that EMT contributes to improving swallowing function by increasing the contraction of the pharyngeal muscles.