Study design
cough, coughs, fatigue
Eligible participants were randomized in a 1:1 ratio into groups I or II without stratification using a computer-generated block size of 4. Group I started in the supine position, was later reclined to 40° on the first day, and then the reclined position first followed by the supine position on the next day. Conversely, Group II underwent four sessions of MI-E in the opposite order of the applying position. The angle of 40°-reclining was chosen because previous studies have shown that this angle can achieve a more effective manual thrust combined with MI-E than in a 90°-sitting positionThe study design provides alternating starting positions of either supine or reclined for each day and each group because the cumulative treatment effect can also affect the generated PCF during MI-E. Consecutive MI-E application with eliminated sputum between coughs affects airway resistance and generates better PCF. However, repetitive cough combined with MI-E assistance would result in fatigue because of repeated maximal effort during exsufflation and decreased PCF. Conversely, if more MI-E treatment sessions are completed, more experienced participants can cooperate better with MI-E, which generates a faster PCF. This bias from repetitions of the MI-E application could be avoided by changing the order of the applied posture for every session for all participants.