Urinary incontinence and impaired physical function are associated with expiratory muscle weakness in patients with multiple sclerosis

Purpose: Patients with multiple sclerosis (MS) with respiratory muscle weakness could have physical function impairments, given the functional/biomechanical link of the trunk stabilising system. Thus, clinicians could employ new treatment strategies targeting respiratory muscles to improve their physical function. This study pretends to evaluate the relationship between respiratory muscle strength, pulmonary function and pelvic floor function, and also to correlate these variables with physical function (gait function, disability and quality of life) in patients with MS. Methods: 41 patients participated in this descriptive cross-sectional study. Respiratory muscle strength [maximal respiratory pressures (MIP/MEP)], pulmonary function (forced spirometry), pelvic floor function [urinary incontinence (UI)], physical function [Timed Up & Go (TUG) test, Barthel index and health status questionnaire (SF-12)] were evaluated. Results: Respiratory muscle strength and pulmonary function were moderately related to UI (MIP: rho = -0.312; MEP: rho = -0.559). MEP was moderately related to physical function (TUG: rho = -0.508; Barthel index: rho = 0.418). Patients with and without expiratory muscle weakness showed differences in UI, pulmonary and physical function. Conclusion: Patients with MS with greater deterioration in pulmonary function and respiratory muscle strength, especially expiratory muscles, showed greater deterioration in UI and physical function. Expiratory muscle weakness had a negative impact on urinary, physical and pulmonary function. IMPLICATIONS FOR REHABILITATION Pulmonary function is associated with urinary incontinence and gait functionality in patients with multiple sclerosis (MS). Expiratory muscle weakness is associated with impaired urinary and physical function in patients with MS. The inclusion of respiratory muscle training to the rehabilitation programs of patients with MS could improve their pelvic floor disorders and physical function.