COPD Patients Exhibit Similar Joint Angle Variability Compared to Older, Healthy Control Subjects
Advisor Information
Jennifer Yentes
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
4-3-2016 12:45 PM
End Date
4-3-2016 2:15 PM
Abstract
Chronic obstructive pulmonary disease (COPD) is a syndrome characterized by limitations in expiratory airflow; however, the effects of the disease reach further than just the respiratory system. Many patients report muscle fatigue as a major symptom leading to functional limitations, like gait. Biomechanical measures of gait have shown little changes in the presence of COPD, however, analyzing the variability of gait may provide additional insight into how gait is controlled. Variability is a scale between completely random and highly patterned. Healthy subjects fall in the middle and are able to adjust their gait when needed. Our purpose was to compare the joint angle variability in COPD patients and healthy controls. It was hypothesized that COPD subjects would display an increase in variability of ankle joint movement during walking as compared to healthy controls as deficits in ankle mechanics in patients with COPD have been determined previously. Nine controls and nine COPD patients walked on a treadmill at their chosen pace. Gait variability was quantified using Lyapunov exponent (LyE), which quantifies the rate at which an attractor is diverging. Larger LyE indicates larger stride-to-stride differences in joint angles, while a smaller value represents a more organized, consistent system. The LyE for the ankle angle was not different between groups as hypothesized. Although no significant differences were found in this study, further investigation into the effects of COPD on gait variability should be done due to variability’s relation with functionality, the small sample size, and the differences between severities of disease.
COPD Patients Exhibit Similar Joint Angle Variability Compared to Older, Healthy Control Subjects
Dr. C.C. and Mabel L. Criss Library
Chronic obstructive pulmonary disease (COPD) is a syndrome characterized by limitations in expiratory airflow; however, the effects of the disease reach further than just the respiratory system. Many patients report muscle fatigue as a major symptom leading to functional limitations, like gait. Biomechanical measures of gait have shown little changes in the presence of COPD, however, analyzing the variability of gait may provide additional insight into how gait is controlled. Variability is a scale between completely random and highly patterned. Healthy subjects fall in the middle and are able to adjust their gait when needed. Our purpose was to compare the joint angle variability in COPD patients and healthy controls. It was hypothesized that COPD subjects would display an increase in variability of ankle joint movement during walking as compared to healthy controls as deficits in ankle mechanics in patients with COPD have been determined previously. Nine controls and nine COPD patients walked on a treadmill at their chosen pace. Gait variability was quantified using Lyapunov exponent (LyE), which quantifies the rate at which an attractor is diverging. Larger LyE indicates larger stride-to-stride differences in joint angles, while a smaller value represents a more organized, consistent system. The LyE for the ankle angle was not different between groups as hypothesized. Although no significant differences were found in this study, further investigation into the effects of COPD on gait variability should be done due to variability’s relation with functionality, the small sample size, and the differences between severities of disease.