Reference equations for quadriceps strength, endurance and power: a multicentre study.

Introduction: The lack of reference values of lower-limb muscle function hinders the clinical recommendations of its measurement in patients with COPD. Therefore, this study aimed to develop reference equations to predict reference values for quadriceps strength, endurance and power and evaluate their construct validity in patients with COPD.

Methods: Quadriceps strength, endurance and power were assessed in 158 healthy individuals and 87 patients with COPD.

Automated O Titration Alone or With High-Flow Nasal Cannula During Walking Exercise in Chronic Lung Diseases.

Background: Exercise-induced O desaturation contributes to dyspnea and exercise intolerance in various respiratory diseases. This study assessed whether automated O titration was superior to fixed-flow O to improve exertional dyspnea and walking exercise endurance. We also aimed at evaluating possible additive effects of high-flow nasal cannula coupled with automated O titration on these outcomes.

Functional clinical impairments and frailty in interstitial lung disease patients.

Background: Patients with interstitial lung disease (ILD) often present with persistent dyspnoea and reduced exercise capacity and quality of life (QoL), but their functional limitation in relation to their frailty status remains unclear. We thus aimed to compare exercise tolerance, functional mobility, and muscle function and composition between ILD participants and healthy subjects and according to their frailty status.

Methods: A total of 36 ILD participants and 15 heathy subjects performed a 6-min walk test, a 1-min sit-to-stand test, a Short Physical Performance Battery test, a hand grip test and complete quadriceps function testing.

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

Quadriceps dysfunction is a common systemic manifestation of chronic obstructive pulmonary disease (COPD), for which treatment using resistance training is highly recommended. Even though training volume is suggested to be a key explanatory factor for intramuscular adaptation to resistance training in healthy older adults, knowledge is scarce on the role of progression of training volume for intramuscular adaptations in COPD. This study was a sub-analysis of a parallel-group randomized controlled trial.

Physical and affective components of dyspnoea are improved by pulmonary rehabilitation in COPD.

Background: Dyspnoea is a multidimensional experience of breathing discomfort, but its affective dimension is unfrequently assessed in people with chronic obstructive pulmonary disease (COPD). We evaluated the effectiveness of a home-based pulmonary rehabilitation (PR) programme on the physical and affective components of dyspnoea assessed by the Dyspnoea-12 (D-12) questionnaire. We also determined the baseline characteristics that contributed to the change in D-12 scores.

Quadriceps physiological response during the 1-min sit-to-stand test in people with severe COPD and healthy controls.

We compared quadriceps oxygenation and surface electromyography (sEMG) responses during the 1-min sit-to-stand (1STS) in 14 people with severe COPD and 12 controls, in whom cardiorespiratory response, near-infrared spectroscopy signals (oxy [Hb-Mb], deoxy [Hb-Mb], total [Hb-Mb], and SmO) and sEMG signals of the quadriceps were recorded. Time duration of each sit-to-stand cycle and the total work performed during the 1STS were measured. The quadriceps oxygenation parameters were normalized by reporting their values according to the total work during 1STS.

Impact of a Mobile Telerehabilitation Solution on Metabolic Health Outcomes and Rehabilitation Adherence in Patients With Obesity: Randomized Controlled Trial.

Background: Obesity is a major public health issue. Combining exercise training, nutrition, and therapeutic education in metabolic rehabilitation (MR) is recommended for obesity management. However, evidence from randomized controlled studies is lacking.

Home-based Pulmonary Rehabilitation is Effective in Frail COPD Patients with Chronic Respiratory Failure.

Daily life disability and vulnerability is often reported in patients with chronic obstructive pulmonary disease (COPD) and chronic respiratory failure. Although pulmonary rehabilitation is feasible in this population, its benefits on functional status and physical frailty is uncertain. This study aimed to evaluate the short- and medium-term effectiveness of a home-based pulmonary rehabilitation program in COPD patients with chronic respiratory failure.

Acute Cardiopulmonary and Muscle Oxygenation Responses to Normocapnic Hyperpnea Exercise in COPD.

Purpose: This study aimed to investigate cardiorespiratory responses and intercostal muscle oxygenation during normocapnic hyperpnea exercise in chronic obstructive pulmonary disease (COPD).

Methods: Twenty-two patients with COPD performed a cardiopulmonary cycling exercise test to assess peak oxygen consumption (V˙O2peak) and minute ventilation (V˙Epeak). They also performed a normocapnic hyperpnea exercise alone, at 50%-60% of V˙Epeak to exhaustion, using a respiratory device (Spirotiger) connected to a gas analyzer to monitor V˙O2, V˙E, and end-tidal CO2 partial pressure.

Isotonic quadriceps endurance is better associated with daily physical activity than quadriceps strength and power in COPD: an international multicentre cross-sectional trial.

Knowledge about modifiable determinants of daily physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) is crucial to design effective PA interventions. The present study aimed to determine the contribution of quadriceps strength, power and endurance to daily PA in COPD. Additionally, for quadriceps endurance, we also aimed to determine to what extent the association varies according to the mode of movement (isotonic, isometric, or isokinetic).

Physical Frailty in COPD Patients with Chronic Respiratory Failure.

Background: The prevalence of physical frailty and its clinical characteristics in advanced chronic obstructive pulmonary disease (COPD) is unknown, as well as the usefulness of functional capacity tests to screen for physical frailty. The aim of the study was to evaluate the proportion and clinical portrait of COPD patients with chronic respiratory failure exhibiting physical frailty at the time of referral to home-based pulmonary rehabilitation. We also evaluate the usefulness of the short physical performance battery (SPPB) and timed-up and go (TUG) as potential screening tools for physical frailty.

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

Objective: Various functional muscle properties affect different aspects of functional exercise capacity in people with chronic obstructive pulmonary disease (COPD). The purpose of this study was to investigate the contribution of quadriceps muscle strength, endurance, and power to 6-Minute Walking Distance (6MWD) and 1-minute sit-to-stand test (1STS) performance in people with COPD.

Methods: The study was a prospective, multicenter, cross-sectional study.

Effects of Low-Load/High-Repetition Resistance Training on Exercise Capacity, Health Status, and Limb Muscle Adaptation in Patients With Severe COPD: A Randomized Controlled Trial.

Background: Training volume is paramount in the magnitude of physiological adaptations following resistance training. However, patients with severe COPD are limited by dyspnea during traditional two-limb low-load/high-repetition resistance training (LLHR-RT), resulting in suboptimal training volumes. During a single exercise session, single-limb LLHR-RT decreases the ventilatory load and enables higher localized training volumes compared with two-limb LLHR-RT.

Long-Term Effectiveness of a Home-Based Pulmonary Rehabilitation in Older People with Chronic Obstructive Pulmonary Disease: A Retrospective Study.

Background: Long-term effectiveness of pulmonary rehabilitation (PR) is still uncertain in older people with severe chronic obstructive pulmonary disease (COPD). The objective was to compare the effects of home-based PR in people with COPD above and below the age of 70 years.

Methods: In this retrospective study, 480 people with COPD were recruited and divided into those ≤70 (n=341) and those >70 years of age (n=139).

Validation and Cardiorespiratory Response of the 1-Min Sit-to-Stand Test in Interstitial Lung Disease.

Purpose: To assess the 1-min sit-to-stand test (1STS) test-retest reliability and construct validity and its associated cardiorespiratory response in comparison to the 6-min walk test (6MWT) and symptom-limited cycling cardiopulmonary exercise test (CPET) in people with interstitial lung disease (ILD).

Methods: Fifteen participants with ILD performed two 1STS tests, a 6MWT and a CPET. The three tests were administered on three separate visits, and cardiorespiratory parameters were continuously recorded during the tests.

Cardiorespiratory Response during the 1-min Sit-to-Stand Test in Chronic Obstructive Pulmonary Disease.

Purpose: This study aimed to assess the cardiorespiratory response during a 1-min sit-to-stand test (1STS) in comparison with cycling cardiopulmonary exercise test (CPET) in people with chronic obstructive pulmonary disease (COPD) and in healthy subjects and to evaluate whether 1STS may induce leg fatigue in these individuals.

Methods: Fourteen people with severe COPD and 12 healthy subjects performed a 1STS and a CPET during which cardiorespiratory response, perception of dyspnea, and leg fatigue were assessed. Quadriceps strength was assessed before and after 1STS, and contractile fatigue was defined as a postexercise fall in quadriceps twitch force greater than 15% of resting values.

Reliability of quadriceps muscle power and explosive force, and relationship to physical function in people with chronic obstructive pulmonary disease: an observational prospective multicenter study.

: Muscle power declines with age and is a stronger determinant of physical function than strength. Muscle power using computerized dynamometry has not been investigated in COPD.: To determine: 1) test-retest reliability of quadriceps power using a standardized protocol with computerized dynamometry; and 2) associations between quadriceps strength and power, and functional capacity.

The Relevance of Limb Muscle Dysfunction in Chronic Obstructive Pulmonary Disease: A Review For Clinicians.

"Chronic obstructive pulmonary disease (COPD) is often accompanied by extrapulmonary manifestations such as limb muscle dysfunction. This term encompasses several features, including atrophy, weakness, and reduced oxidative capacity. Clinicians should become accustomed with this manifestation of COPD because of its relevance for important outcomes such as exercise tolerance and survival.

Fixed Handheld Dynamometry Provides Reliable and Valid Values for Quadriceps Isometric Strength in People With Chronic Obstructive Pulmonary Disease: A Multicenter Study.

Background: Quadriceps weakness is associated with poor clinical outcomes in chronic obstructive pulmonary disease (COPD). However, quadriceps isometric strength assessment has not been routinely adopted in clinical practice because of the lack of homogeneity in the devices and protocols and the lack of reliability studies.

Objective: The objectives of this study were to determine the test-retest reliability and the criterion validity of a commercially available handheld dynamometer for evaluating the quadriceps isometric maximal voluntary contraction (iMVCquad) using a standardized protocol and to investigate the relationship between iMVCquad and functional capacity in people with COPD.

Inter-day test-retest reliability and feasibility of isokinetic, isometric, and isotonic measurements to assess quadriceps endurance in people with chronic obstructive pulmonary disease: A multicenter study.

The aims were to determine reliability and feasibility of measurements to assess quadriceps endurance in people with chronic obstructive pulmonary disease. Sixty participants (forced expiratory volume in one second (mean ± standard deviation) 55 ± 18% of predicted, age 67 ± 8 years) were tested in an inter-day, test-retest design. Isokinetic, isometric, and isotonic protocols were performed using a computerized dynamometer.

Effect and feasibility of non-linear periodized resistance training in people with COPD: study protocol for a randomized controlled trial.

Background: In people with chronic obstructive pulmonary disease (COPD), limb-muscle dysfunction is one of the most troublesome systemic manifestations of the disease, which at the functional level is evidenced by reduced strength and endurance of limb muscles. Improving limb-muscle function is an important therapeutic goal of COPD management, for which resistance training is recommended. However, current guidelines for resistance training in COPD mainly focus on improving muscle strength which only reflects one aspect of limb-muscle function and does not address the issue of reduced muscle endurance.

Cardiorespiratory and Muscle Oxygenation Responses to Isokinetic Exercise in Chronic Obstructive Pulmonary Disease.

Purpose: This study aimed to describe cardiorespiratory, quadriceps oxygenation, and muscle fatigue responses during a one-legged quadriceps isokinetic endurance exercise in chronic obstructive pulmonary disease (COPD) and control subjects.

Methods: Fourteen patients with COPD and 14 control subjects performed a cardiopulmonary cycling exercise test to exhaustion to assess peak oxygen consumption (V˙O2peak), minute ventilation (V˙Epeak), and heart rate (HRpeak). They also performed a quadriceps isokinetic endurance exercise consisting in 30 maximal knee extensions at 90°·s with continuous monitoring of expired gases, cardiac output, and oxygenation of the quadriceps by near-infrared spectroscopy.

Active mind-body movement therapies as an adjunct to or in comparison with pulmonary rehabilitation for people with chronic obstructive pulmonary disease.

Background: Active mind-body movement therapies (AMBMTs), including but not limited to yoga, tai chi, and qigong, have been applied as exercise modalities for people with chronic obstructive pulmonary disease (COPD). AMBMT strategies have been found to be more effective than usual care; however, whether AMBMT is inferior, equivalent, or superior to pulmonary rehabilitation (PR) in people with COPD remains to be determined.

Objectives: To assess the effects of AMBMTs compared with, or in addition to, PR in the management of COPD.

Test-re-test reliability of quadriceps muscle strength measures in people with more severe chronic obstructive pulmonary disease.

Objective: To investigate the interday test-retest reliability of volitional and non-volitional measurements of isometric quadriceps strength using a strain-gauge in people with severe to very severe chronic obstructive pulmonary disease.

Design: Cross-sectional study. Volitional quadriceps measurements consisted of isometric maximal voluntary contractions.