INTRODUCTION: Advanced air-flow limitation in patients with COPD leads to a reduction in vital capacity, respiratory muscle strength, and exercise capacity. However, its impact on chest and abdominal wall mobility is unknown. This study aimed to ascertain the prevalence of patients with COPD with reduced chest and abdominal wall mobility and to investigate the effect of reduced chest and abdominal wall mobility on pulmonary function, respiratory muscle strength, and exercise capacity. METHODS: In 51 elderly male subjects with COPD, chest and abdominal wall mobility, FVC, FEV1, FEV1/FVC, maximal inspiratory pressure (P-Imax), maximal expiratory pressure (P-Emax), and the 6-min walk distance (6MWD) were assessed. Chest and abdominal wall mobility were measured using the breathing movement scale (0-8) at the 3 regions (upper chest, lower chest, and abdomen). Reduced mobility was defined as a value lower than the lower limit of the normal scale. The unpaired t test, Mann-Whitney test, and multiple regression analysis were performed. RESULTS: The percentages of subjects with reduced mobility were 78% for the upper chest, 76% for the lower chest, and 53% for the abdomen. The subjects with reduced mobility had significantly low FVC, FEV1, and 6MWD in each region and significantly low FEV1/FVC, PImax, and PEmax in the abdominal region compared with those with nonreduced mobility. FVC and 6MWD were independently associated with the scale values in each region and with the abdominal scale value, respectively. CONCLUSIONS: The majority of subjects with COPD had reduced chest and abdominal wall mobility, which was independently associated with FVC. Even though abdominal wall mobility was relatively preserved compared with chest wall mobility, it was also independently associated with 6MWD.