Neuromuscular weakness in chronic obstructive pulmonary disease: chest wall, diaphragm, and peripheral muscle contributions.

PURPOSE OF REVIEW: Chronic obstructive lung disease affects the lung parenchyma and airways leading to well described effects in respiratory function. This review describes the current knowledge and advances regarding neuromuscular function and chest wall mechanics, which are affected in chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS: In COPD, progressive lung hyperinflation becomes constrained by a chest wall with decreasing capacity to expand, resulting in respiratory muscle inefficiency. There is evidence of neuromuscular uncoupling, that is, the respiratory muscle is unable to increase its output in proportion to increasing neural signals. COPD patients also have evidence of altered peripheral muscles function. The end effect of all these pathological changes is neuromuscular weakness.

SUMMARY: Respiratory and peripheral muscles dysfunction is found in patients with COPD. This manifests clinically as dyspnea, poor exercise capacity, and decreased quality of life. We have clear evidence that rehabilitation helps several aspects of patients with COPD. Further understanding of the physiopathology is needed to improve our therapeutic and rehabilitation strategies.