A low maximum inspiratory pressure is not the same as respiratory muscle weakness.
Davis
M P
MP
D006801:Humans; D008173:Lung Diseases, Obstructive / Q000150:complications / Q000503:physiopathology*; D018908:Muscle Weakness / Q000209:etiology / Q000503:physiopathology*; D009369:Neoplasms / Q000150:complications / Q000503:physiopathology*; D011312:Pressure; D012119:Respiration; D012132:Respiratory Muscles / Q000503:physiopathology*; D012720:Severity of Illness Index; D013147:Spirometry