Bipedal postural control in severe COPD patients with bronchitic and emphysematic phenotype

Abstract

Introduction: Balance impairments confirmed in COPD patients are associated with severity of airflow limitation, muscle weakness, frequency of falls and reduced physical activity level. However, the relationship between balance and COPD phenotypes has been not studied yet. This study aimed to investigate postural control deficits in COPD patients with bronchitic (BP) and emphysematic (EP) phenotype and to evaluate the effect of self-reported history of falls or frequent stumbling on postural control. Methods: 10 COPD patients with EP (FEV 1 =45.5%) and 10 COPD patients with BP (FEV 1 =50%) were randomly recruited from the Czech Multicentre Research Database of COPD. Patients and 10 age-matched healthy controls (FEV 1 =93.6%) were instructed to stand upright as immobile as possible feet together with their eyes open. Centre of pressure (CoP) displacements were computed using force plates. Patients with previous fall or frequent stumbling were categorized as fallers, those without as non-fallers. Results: Although number of fallers was higher in BP group (70%) compared to EP group (30%), postural stability did not differ between patients with BP, EP and controls. Anterior-posterior (AP) CoP displacement was higher in fallers compared to non-fallers (p=0.02) and controls (p=0.02). Mean velocity in mediolateral (ML) direction and ML CoP displacement were higher in fallers than in non-fallers (p=0.03). Conclusion: Fallers had higher postural sways in AP and ML directions. Higher incidence of falls and stumbling in severe COPD patients indicates that balance assessment should be an integral part of their complex evaluation. It seems that BP and EP do not have any significant effect on postural stability.