Objective: To compare the effects of expiratory muscle training and sham training on respiratory muscle strength in patients with multiple sclerosis (MS).
Design: A randomized control trial; subjects were randomly assigned to either expiratory muscle training or sham training.
Setting: Training and measurement of respiratory muscle pressures were conducted in patients' homes. Weekly home visits were conducted to assure compliance with the training protocols and to obtain measurements.
Patients: Twenty subjects with clinically definite MS and decreased expiratory muscle strength entered the study; 10 subjects completed 3 months of expiratory training using a threshold training device and 5 subjects completed 3 months of sham training using the same device but without an expiratory training threshold load.
Measurement: Respiratory muscle strength was assessed at baseline and after 1, 2, and 3 months of training; maximal inspiratory and expiratory pressures were used as measures of respiratory muscle strength.
Results: There was a significant increase in expiratory muscle strength after 3 months of training when the expiratory training group was compared to the sham group (p = .003); no significant change in inspiratory muscle strength was observed.
Conclusions: The results of this pilot study suggest that the strength of the expiratory muscles of persons with MS can be increased through respiratory muscle training targeted to the expiratory muscles. Further research is indicated to determine if increasing the strength of the expiratory muscles in MS has an effect on clinical outcomes in this patient population.