Related Experiment Video
Updated: Jun 7, 2026

Home-Based Prescribed Pulmonary Exercise in Patients with Stable Chronic Obstructive Pulmonary Disease
Published on: August 24, 2019
Deficits in muscle strength, mass, quality, and mobility in people with chronic obstructive pulmonary disease
Marc Roig1, Janice J Eng, Donna L MacIntyre
1Department of Physical Therapy, University of British Columbia, Vancouver, Canada. markredj@interchange.ubc.ca
Purpose:
Midthigh intramuscular fat (IF), a feature of reduced muscle quality, is an important predictor of self-reported mobility loss in the elderly. This study compared measures of muscle strength, mass, IF, and mobility in patients with chronic obstructive pulmonary disease (COPD) and healthy subjects. Associations between measures of muscle strength, mass, IF, and mobility were explored.
Methods:
Knee extensor muscle strength was assessed with an isokinetic dynamometer. Cross-sectional area and IF of the thigh muscles were measured with computerized tomography. Mobility was assessed with the repetitive sit-to-stand, self-selected gait speed, and 6-minute walk tests.
Results:
Patients with COPD (n = 21, age 71.3 ± 8.1 years, and a percentage predicted force expiratory volume in 1 second of 47.2 ± 12.9) and 21 healthy subjects matched for age (67.4 ± 8.6 years), gender, and body mass participated in the study. Patients with COPD showed reduced average knee extensor strength (29%, P = .016) cross-sectional area of the thigh muscles (17%, P = .007) and mobility measures (~23%, P ≤ .001). Knee extensor and flexor IF was 2-folds greater in people with COPD (P ≤ .005). Measures of knee extensor muscle strength, mass, and IF were not associated with mobility measures.
Conclusions:
Compared with healthy controls, patients with moderate to severe COPD show marked deficits in muscle strength, mass, quality, and mobility. More studies with larger sample size are required to elucidate whether any of these muscle deficits can explain mobility impairments in COPD.
Related Concept Videos
Chronic Obstructive Pulmonary Disease-III: Symptoms and Complications.
Symptoms of COPD can be classified as primary or systemic. Primary symptoms relate to reduced airflow, while systemic or extrapulmonary symptoms relate to COPD's broader impact on the body.
Primary Symptoms of COPD:
Chronic Obstructive Pulmonary Disease
Smoking is a primary risk factor for COPD, with over 80% of patients having a history of it. Patients typically experience progressive dyspnea or labored breathing, frequent coughing, and recurrent pulmonary infections. Many eventually succumb to respiratory failure, characterized by...
Chronic Obstructive Pulmonary Disease IV: Clinical Manifestations
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features
Chronic Obstructive Pulmonary Disease-I: Introduction