Specific Contribution of Quadriceps Muscle Strength, Endurance, and Power to Functional Exercise Capacity in People With Chronic Obstructive Pulmonary Disease: A Multicenter Study

Abstract

Objective Various functional muscle properties affect different aspects of functional exercise capacity in people with COPD. The purpose of this study was to investigate the contribution of quadriceps muscle strength, endurance, and power to the 6-minute walking distance (6MWD) and the 1-minute sit-to-stand test (1STS) performance in people with COPD. Methods The study was a prospective, multicenter cross-sectional study. Anthropometrics, Medical Research Council (MRC) dyspnea scale, lung function, 6MWD and the 1STS number of repetitions were assessed. Isometric quadriceps strength (Strength-ISOM) and endurance (Endurance-ISOM), isotonic quadriceps endurance (Endurance-ISOT), isokinetic quadriceps strength (Strength-ISOKIN), and power (Power-ISOKIN) were assessed on a computerized dynamometer while functional quadriceps power was determined during 5 sit-to-stand repetitions (Power-5STS). Univariate and multivariate analyses were performed to determine the contribution of functional muscle properties on the 6MWD and the 1STS number of repetitions. Results The study included 70 people with COPD (mean % predicted FEV1 = 58.9 [SD = 18.2]). The 6MWD correlated with each functional muscle property, except the Endurance-ISOM. The number of repetitions during the 1STS correlated with each functional muscle property except isometric measurements. Multivariate models explained respectively 60% and 39% of the variance in the 6MWD and 1STS number of repetitions, with Power-5STS being the muscle functional property with the strongest contribution to the models. Conclusion Except for isometric endurance, quadriceps strength, endurance, and power were associated with functional exercise capacity in people with moderate COPD. Among these functional muscle properties, muscle power contributed the most to the 6MWD and 1STS number of repetitions, suggesting that muscle power is more relevant to functional exercise capacity than muscle strength or endurance in people with COPD. Impact Understanding the individual contribution of muscle properties to functional status is important to designing interventions. This study provides the guidance that muscle power may be more important to functional exercise capacity than muscle strength or endurance in people with COPD.

Functional Status Following Pulmonary Rehabilitation: Responders and Non-Responders

“…A previous study has shown isometric quadriceps muscle strength to be a predictor of response to PR in the 6MWT [42]. However, we did not find it as a predictor and a recent study found no correlations between isometric measurements of muscle function and the 1 min STS, with muscle power measured by isokinetic or the 5-time STS being the main contributor to the 1 min STS and the 6MWT performance [43]. Hence, dynamic measurements and more robust measures (e.g., isokinetic) should be further explored in the future, as they could be highly relevant to assess and predict the response to PR.…”

Role of progression of training volume on intramuscular adaptations in patients with chronic obstructive pulmonary disease

“…Thus, taken together, our results support and extend previous observations (Sale, 1988;Folland and Williams, 2007;Škarabot et al, 2021) by suggesting that training volume, and specifically the continued progression of training volume after the initial weeks of training, is necessary to enable morphological and structural adaptations and thus, counteract quadriceps dysfunction within the COPD population. These findings are relevant to COPD management considering the high prevalence and adverse consequences of quadriceps dysfunction in this population (Swallow et al, 2007;Maltais et al, 2014;Frykholm, 2020;Géphine et al, 2021).…”

“…Elastic work was measured during the first set from the number of repetitions multiplied by the load provided by the elastic band ([Kg] at 100% elongation)( Nyberg et al, 2021 ). Importantly, isokinetic and elastic assessments were performed using valid and reliable test procedures for COPD ( Evans et al, 2014 ; Nyberg et al, 2018 ; Frykholm et al, 2019 ; Frykholm, 2020 ; Géphine et al, 2021 ).…”

“…The quadriceps is also more susceptible to fatigue when compared to healthy age-matched older adults, a situation that worsens with disease severity ( Boccia et al, 2015 ; Boccia et al, 2016 ). Furthermore, quadriceps dysfunction is intimately linked with important clinical and prognostic outcomes, including exercise tolerance, daily physical activity, and even mortality ( Swallow et al, 2007 ; Maltais et al, 2014 ; Frykholm, 2020 ; Géphine et al, 2021 ). Thus, counteracting quadriceps dysfunction is emphasized as a critical goal of COPD management ( Spruit et al, 2013 ; Maltais et al, 2014 ; Marklund et al, 2019 ; Marillier et al, 2020 ), for which exercise training, specifically resistance training, is recommended over other available treatment modalities, irrespective of being performed alone or in combination with endurance training ( Spruit et al, 2002 ; Troosters et al, 2010 ; Iepsen et al, 2015a ; Iepsen et al, 2015b ; Rinaldo et al, 2017 ; Jaitovich and Barreiro, 2018 ; Marklund et al, 2019 ).…”

Muscle function and functional performance after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease: a prospective observational study

“…In order to provide individualized exercise prescriptions to patients with COPD, several muscle properties that may contribute to skeletal muscle dysfunction need to be assessed 8 . For example, the modality (i.e., isometric, concentric, and eccentric), velocity (i.e., muscle power and rate of force development (RFD)), and fluctuation (i.e., force steadiness) of muscle contraction produce different effects on skeletal muscle function in older healthy adults 9 .…”