Respiratory muscle strength
Maximum Inspiratory Pressure (MIP) and Maximum Expiratory
Pressure (MEP) were measured as per the methods
described by Black and Hyatt22 using a handheld mouth
pressure meter (MicroRPM Respiratory Pressure Meter,
Micromedical Ltd, UK). For measuring MIP, patients were
instructed to exhale to residual volume and then inhale
forcefully and maintain maximum pressure for 1 s. To
measure MEP, patients were instructed to inhale to total
lung capacity and then exhale forcefully and maintain
maximum pressure for 1 s.