The Effects of Inspiratory Pressures on Diaphragmatic Contraction in People After Stroke

Each participant will be asked to perform the lung function test to measure the maximal inspiratory pressure (MIP) after including the study. After the baseline measurement, all participants will be requested to use a nose clip to hold the nose and breathe with the mouth through a pressure threshold inspiratory loading device (POWERbreathe, KH2, England). The inspiratory pressure will be set at 30%, 40%, 50%, 60%, 70%, or 80% of their MIP, in random order. Each MIP intensity protocol consists of 10 breaths. Resting will be allowed between different protocols of contraction intensity (% MIP). During the test, sternocleidomastoid muscle activity will be measured with surface electromyography (sEMG) and diaphragm thickness will be used to assessed with ultrasonography.