Abnormalities of pulmonary mechanics [e.g. pulmonary edema, pneumonia] are depicted by shifts in the curve labeled 'static pulmonary properties' whereas abnormalities of chest wall mechanics are depicted by shifts in the curve labeled 'static chest wall properties' [e.g. ascites, obesity].  Abnormalities of airways resistance are marked by changes in the curve labeled 'dynamic respiratory properties' [e.g. COPD exacerbation].

A graphical means of assessing the relationship between intra-thoracic pressure or pleural pressure [on the x-axis] and thoracic volume [on the y-axis] as a function of airway resistance, lung compliance and chest wall compliance.