Effect of inspiratory muscle training (IMT) on aerobic capacity, respiratory muscle strength and rate of perceived exertion in paraplegics

Objectives: The purpose is to study the effect of inspiratory muscle training on aerobic capacity, respiratory muscle strength and rate of perceived exertion in paraplegics. Study Design: Randomized controlled trial. Settings: Rehabilitation department in Indian Spinal Injuries Centre, New Delhi. Participants: A sample of 30 paraplegics (T1-T12) were randomly allocated into two groups: inspiratory muscle training (IMT) group and control group. Interventions: The IMT group received inspiratory muscle training for 15 minutes 5 times a week for 4 weeks whereas the control group was given breathing exercises. Outcome measures: Maximal inspiratory pressure(MIP), maximal expiratory pressure (MEP), modified Borg's scale (MBS), 12 minute wheelchair aerobic test (12MWAT), multistage fitness test (MSFT), and 6 minutes push test (6MPT). Results: Out of 30 participants, 27 completed the study. The results show that after four weeks of IMT training, there were significant improvements in mean change scores of IMT group as compared to control group. Participants in IMT group performed better on 12MWAT (P = 0.001), MSFT (P = 0.001) and 6MPT (P = 0.001). Improvements in MIP scores (P = 0.001), MEP scores (P = 0.001) and MBS scores (P = 0.004) were also seen in IMT group. Conclusion: Both groups showed significant improvements, however inspiratory muscle training was seen to be more effective than deep breathing exercises for improving aerobic capacity, respiratory muscle strength and rate of perceived exertion in paraplegics.