The optimal treatment duration for inspiratory muscle strengthening exercises in stroke patients: a double-blinded randomized controlled trial.

BACKGROUND

Little is known about the ideal duration of inspiratory muscle training in stroke patients.

OBJECTIVE

The aim of this study was to assess the effects of short-term and long-term inspiratory muscle strengthening exercises in stroke patients.

METHODS

This study was a prospective, double-blind, randomized controlled trial involving 50 stroke patients. Based on baseline maximum inspiratory pressure (MIP) values, participants were divided into two strata: those with severely weak inspiratory muscle (stratum A) and those with moderately weak inspiratory muscle (stratum B). Within each stratum, individuals were randomly assigned to either the 4-week exercise group, the 8-week exercise group, or the sham group. The exercise groups underwent inspiratory muscle strengthening exercises. The MIP, 6-minute walk test (6MWT), and the Nottingham Extended Activities of Daily Living (NEADL) Index were assessed at baseline, 8, 12, and 24 weeks.

RESULTS

Subjects in Stratum A exhibited notably greater improvement after 8 weeks of training compared to those in Stratum B. Furthermore, both Stratums displayed significantly greater improvement following 8 weeks of training compared to sham training. In Stratum B cases, a significantly higher level of improvement was noted with the 4-week training in comparison to the sham training. A significant increase in NEADL index and 6MWT score was observed during the 24-week follow-up period.

CONCLUSION

For individuals with moderately weak inspiratory muscle strength, a 4-week exercise program proves sufficient in enhancing inspiratory muscle strength, walking capacity, and daily life activities. However, individuals with severely weak inspiratory muscle strength benefit more from an 8-week treatment.