Differences in walking pattern during 6-min walk test between patients with COPD and healthy subjects

• Published in: PloS one 2012-05, Vol.7 (5), p.e37329
• Main Authors: Annegarn, Janneke, Spruit, Martijn A, Savelberg, Hans H C M, Willems, Paul J B, van de Bool, Coby, Schols, Annemie M W J, Wouters, Emiel F M, Meijer, Kenneth
• Format: Article
• Language: English
• Subjects: Accelerometers; Biomechanical Phenomena; Case-Control Studies; Chronic obstructive lung disease; Chronic obstructive pulmonary disease; Comparative analysis; Determinants; Dyspnea; Elderly; Engineering; Exercise; Gait - physiology; Geriatrics; Health risk assessment; Humans; Lung diseases; Medicine; Metabolism; Nutrition; Obstructive lung disease; Older people; Patients; Physical fitness; Physiology; Pulmonary Disease, Chronic Obstructive - physiopathology; Regression analysis; Regression models; Rehabilitation; Time Factors; Toxicology; Validation studies; Variability; Walking; Walking - physiology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0037329

To date, detailed analyses of walking patterns using accelerometers during the 6-min walk test (6MWT) have not been performed in patients with chronic obstructive pulmonary disease (COPD). Therefore, it remains unclear whether and to what extent COPD patients have an altered walking pattern during the 6MWT compared to healthy elderly subjects. 79 COPD patients and 24 healthy elderly subjects performed the 6MWT wearing an accelerometer attached to the trunk. The accelerometer features (walking intensity, cadence, and walking variability) and subject characteristics were assessed and compared between groups. Moreover, associations were sought with 6-min walk distance (6MWD) using multiple ordinary least squares (OLS) regression models. COPD patients walked with a significantly lower walking intensity, lower cadence and increased walking variability compared to healthy subjects. Walking intensity and height were the only two significant determinants of 6MWD in healthy subjects, explaining 85% of the variance in 6MWD. In COPD patients also age, cadence, walking variability measures and their interactions were included were significant determinants of 6MWD (total variance in 6MWD explained: 88%). COPD patients have an altered walking pattern during 6MWT compared to healthy subjects. These differences in walking pattern partially explain the lower 6MWD in patients with COPD.