Effects of inspiratory muscle training on upper extremity functional exercise capacity and muscle oxygenation in patients with parkinson's disease: a pilot study

<bold>Aim:</bold> Impaired respiratory muscle function, playing essential roles during respiration and upper extremity movement, results in inadequate respiration and impaired upper extremity exercise capacity. To investigate the effect of inspiratory muscle strength training (IMST) on pulmonary function, respiratory muscle strength, upper extremity functional capacity, muscle oxygenation, dyspnea, and fatigue in patients with Parkinson's disease (PD). <bold>Methods:</bold> A randomized, controlled, triple-blind study. Ten patients with PD in each group, IMST (%50 of MIP) group, and control group (breathing exercises) for 7 days/8 weeks were applied. Pulmonary function, respiratory muscle strength (MIP, MEP), upper extremity functional capacity (6-minute pegboard and ring test (6-PBRT)), dyspnea (Modified Medical Research Council (mMRC)) and fatigue (Parkinson Fatigue Scale (PFS)) were evaluated. Deltoid muscle oxygenation (NIRS) was measured during 6-PBRT. <bold>Results:</bold> There was a significant improvement in the 6-PBRT number of rings, MIP, MEP, mMRC and PFS scores after IMST (p<0.05). No improvement was prevalent within and between groups in muscle oxygen and pulmonary function parameters (p>0.05). <bold>Conclusions:</bold> The IMST improves respiratory muscle strength and upper extremity functional capacity and decreases dyspnea and fatigue in patients with PD with preserved pulmonary function. Also, higher exercise workloads were achieved at the same muscle oxygen level after IMST in patients. In addition to rehabilitation, IMST should be used to ensure functional recovery by providing optimal workload distribution between respiration and upper extremity function.