This quasi-experimental study with a pretest-posttest design evaluates the effect of a 6-week structured threshold inspiratory muscle training program on diaphragm thickness and diaphragm excursion in patients with stable COPD. Conducted at the medical rehabilitation polyclinic of Rotinsulu Hospital, Bandung, this study includes patients who meet specific inclusion criteria. The intervention is performed once daily, five times per week, with progressive intensity based on maximal inspiratory pressure using a threshold device. Outcomes will be assessed using ultrasonography to measure diaphragm thickness and diaphragm excursion before and after the intervention.
