COPD and walking abnormalities

Muscular dysfunction is a common symptom of COPD patients and is most often related to lack of physical activity. People who suffer from chronic shortness of breath tend to limit physical activity in order to avoid dyspnea events (shortness of breath episodes). The downside of limiting physical activity for an extended period of time is that as a person becomes more sedentary, the body loses its cardiovascular and muscular conditioning. This in turn results in persistent fatigue, greater dyspnea events and creates a vicious cycle of physical de-conditioning. One way this de-conditioning is evidenced is through walking gait abnormalities such as limping and shuffling as muscle fibers change/weaken from lack of use.

A new study published this month online ahead of print examined the association between walking abnormalities and COPD and determined there is a direct correlation between the presence of walking abnormalities and severity of COPD. (Yentes J, et al. Walking abnormalities are associated with COPD: An investigation of the NHANES III dataset. Respiratory Medicine. 2010 Jul 6. Epub ahead of print)

According to the study authors, while other research studies have examined the connection between COPD severity/physical activity level related to respiratory function, muscle strength, and cardiovascular conditioning, this is the first study to examine the association between COPD severity and walking gait abnormalities. As the researchers explained, “There is evidence that lack of physical activity contributes to peripheral muscle abnormalities and dysfunction.

Disuse of the muscular system can result in muscular atrophy, decreased muscle strength, increased muscle fatigability, reduced oxidative capacity, and capillary loss…These muscular impairments may also lead to abnormal walking patterns; however this has not previously been tested in COPD.”

In their study, the researchers sampled medical records of approximately 8,400 U.S. adults from the NHANES III database. The NHANES III database contains the medical records of over 31,000 U.S. adults who agreed to be examined and surveyed between 1988 and 1994 and is sampled in a wide range of medical research.

The 8,400 patient records were selected based on criteria established by the research team, including age, walking status, and respiratory function measures. Once selected, the research team then examined the statistical relationship between COPD severity and walking gait abnormalities (defined in the study as either a chronic limp or shuffle). They determined that severe COPD patients had almost 2 times the odds of a walking gait abnormality compared to those with mild or moderate COPD (there was not a statistically significant difference between mild and moderate COPD patients).

They researchers concluded, “The novel finding is that COPD is related to walking abnormalities. When using a comprehensive classification scheme for COPD status, a significant association between severe COPD status and walking abnormalities was observed. From clinical point of view, reduced physical activity in daily life and impaired muscle strength are the most likely causes. This was confirmed as demonstrated by decreased physical activity being significantly associated will all levels of COPD severity. These results strengthen the novel findings by demonstrating the importance of physical activity and the effect of inactivity on walking abnormalities.”

We wholeheartedly agree with this last statement. Research study after research study has shown that physical activity/exercise in COPD patients actually reduces fatigue and shortness of breath events in addition to building cardiovascular function, stronger muscle fibers, and higher quality of life. These are the primary goals behind the treatment option known as pulmonary rehabilitation and are the basis of our exercise recommendations in the Breathe Better for Life guidebook, www.breathebetterforlife.com.

While the study authors do not suggest that COPD patients who have walking gait abnormalities may see the abnormalities diminished or eliminated by engaging in regular physical activity/exercise, they do suggest that there is likely a correlation between inactivity and the development of walking abnormalities.

Whether regular physical activity/exercise can reverse a walking gait abnormality or not, the other benefits gained by COPD patients from regular physical activity/exercise are unambiguous. As the study authors offered, “…studies have demonstrated positive effects of exercise training on COPD patients. These positive effects include increased muscular size, strength, power, endurance, mitochondrial capacity, and restoration of protein levels.”