Proposed novel treatment paradigm of aberrant gait and balance kinematics in patients with severe COPD

Abstract

Proposed novel treatment paradigm of aberrant gait and balance kinematics in patients with severe COPD Patients with severe chronic obstructive pulmonary disease (COPD; forced expiratory volume in 1 s [FEV 1 ] < 50% predicted) often report limited participation in walking and exercise activities irrespective of the severity of dyspnoea. 1,2 This, in turn, could constrain their activities of daily living, including outdoor ventures, adversely affect quality of life and increase the risk of acute exacerbations. 3 However, the pathophysiological mechanisms underlying this phenomenon have not been clearly elucidated. Addressing this knowledge gap is important because it could stimulate the development of evidence-based, innovative therapeutic interventions to enable these high-risk patients to perform regular physical activity and exercise thereby improving quality of life and health outcomes.Clinical evidence informs that lower limb muscle strength and endurance along with cognition are impaired in patients with severe COPD. [2][3][4][5] Conceivably, this could promote aberrant gait and balance kinematics which, in turn, may hinder physical activity and exercise capacity and worsen dyspnoea during activities of daily living. 6 To that end, Yentes et al. interrogated the large (n = 31,000) National Health and Nutritional Examination Survey (NHANES) III data set and a found significant correlation between the presence of altered gait and severe COPD. 7 Decreased physical activity was also significantly associated with severe COPD. In a recent review of seven studies comprising 375 elderly patients (64-75 years) with predominantly severe COPD, Zago et al. reported that gait abnormalities observed in these patients comprised of reduced step length and rhythm, and spatiotemporal inconsistency in gait patterns during ambulation. 8 In addition, Morlino et al. proposed that aberrant gait and balance kinematics observed in patients with severe COPD could be related, in part, to damaged neuronal circuits that subserve those functional outcomes in the brain. 2 Despite recent progress in medical research, the pathogenesis of aberrant gait and balance kinematics observed in patients with severe COPD remains elusive. In fact, a comprehensive, 8-week pulmonary rehabilitation programme comprising of 40 sessions of physical exercise training failed to improve stride-to-stride fluctuations (a component of the capacity to adapt walking patterns) in 44 patients with predominantly moderate COPD (mean FEV 1 % predicted, 56%). 9 However, this study did not target specific pathophysiological mechanisms that may underly aberrant gait and balance kinematics in these patients. To the best of our