Measurement of Peripheral Muscle Strength in Individuals With Chronic Obstructive Pulmonary Disease: A Systematic Review

Timed "up and go" to identify physically inactive individuals with interstitial lung disease

OBJECTIVE

To investigate the relationship between the timed "up and go" (TUG) test and physical activity in daily life (PADL) in patients with interstitial lung disease (ILD) and propose a cutoff point to identify physically inactive individuals.

METHODS

Participants performed the TUG test at a usual pace (TUGusual) and at a fast pace (TUGfast). Exercise capacity was assessed by the six-minute walk test, lung function was assessed by whole-body plethysmography, quadriceps strength was assessed by maximal voluntary isometric contraction, and PADL was assessed by an activity monitor worn for six consecutive days. PADL variables included number of steps/day, time spent/day in activities of different intensities, and time spent/day in different postures. A ROC curve was plotted to identify physically inactive individuals on the basis of daily steps (5,000 steps/day) and moderate to vigorous physical activity (MVPA; 30 min/day).

RESULTS

Fifty-three ILD patients (26 women, with a mean age of 60 ± 11 years) were included in the study. TUGusual and TUGfast correlated moderately with the number of steps/day and time spent/day in light physical activity and MVPA (-0.60 < r < -0.41; p < 0.05 for all). ROC curves for TUGusual showed that the cutoffs of ≥ 9.25 s and ≥ 7.9 s can identify physically inactive individuals on the basis of 5,000 steps/day (AUC: 0.73; sensitivity, 76%; specificity, 70%) and 30 min/day of MVPA (AUC: 0.85; sensitivity, 90%; specificity, 75%). Participants who performed worse on TUGusual (i.e., ≥ 9.25 s) showed lower peripheral muscle strength, exercise capacity, and PADL.

CONCLUSIONS

Performance on TUGusual and TUGfast correlates moderately with PADL in patients with ILD. A TUGusual performance ≥ 9.25 s appears to be able to identify physically inactive individuals in this population.

Effectiveness of Rehabilitation Interventions in Adults With Asthma: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study is to evaluate the effectiveness of pulmonary rehabilitation programs and other rehabilitation interventions in adults with asthma.

DESIGN

This is a systematic review and meta-analysis.

RESULTS

MEDLINE (PubMed), Embase, Cumulative Index to Nursing & Allied Health Literature, and CENTRAL were searched from inception to 31 May 2023. PROSPERO registration number: CRD42022331440. Thirty-six randomized controlled trials were analyzed, and only 26 were pooled in the meta-analysis because of the heterogeneity of comparisons and outcomes across the studies. Pulmonary rehabilitation, compared with education associated with breathing exercises, may result in little to no difference in the Asthma Quality of Life Questionnaire (mean difference 0.01 score, 95% confidence interval = -0.48 to 0.50, 163 participants, three studies, low certainty).

CONCLUSIONS

Our findings show that pulmonary rehabilitation, compared with education associated with breathing exercises, may result in little to no difference in the impact of asthma on health-related quality of life. Overall, the certainty of evidence was low or very low preventing any firm conclusion on the effects of single or combined rehabilitation interventions.

Assessment of Muscular Strength and Functional Capacity in Smoker Population Without Any Diagnosed Respiratory Disease: A Cross-Sectional Study

Introduction: Smoking is a risk factor for chronic obstructive pulmonary disease (COPD) and lung cancer. In addition to pulmonary damages, peripheral muscle impairments are present in this population. Pulmonary limitation is observed in smokers before disease diagnosis, but functional capacity limitations are uncertain, contrary to patients who have already been diagnosed. The aim of this study was to compare muscular strength and endurance between non-smoker and smoker populations without any diagnosed respiratory disease. Method: This cross-sectional study assessed subjects without diagnosed respiratory disease in terms of physical capacity using two tests (one-minute sit-to-stand test (STST) and Jamar dynamometer test (JDT)). Results: The sample consisted of 147 subjects. The number of repetitions and the muscle strength were lower in the smoker than in the non-smoker population (28.5 ± 8.7 vs. 33.5 ± 8.2 (p < 0.001), and 38.2 ± 10.1 vs. 42.4 ± 10.5 (p = 0.04), respectively). The relative change in heart rate during STST was lower in the smokers compared to the non-smokers (p = 0.01). No significant differences were found based on gender. Conclusions: Smokers without alcohol or drug dependence and without diagnosed lung disease exhibit non-clinically but statistically reduced muscular strength and endurance. Their heart rate response to exercise is also reduced.

Investigation of Inspiratory Muscle Training Efficiency Before Bronchoscopic Lung Volume Reduction: A Randomized Controlled Trial

INTRODUCTION

Pulmonary rehabilitation (PR) is recommended prior to bronchoscopic lung volume reduction (BLVR) procedures to optimize patient outcomes. However, there's a lack of clear guidance on PR content. The aim of our study is to examine the effect of adding inspiratory muscle training (IMT) to standard PR before BLVR on exercise capacity, dyspnea, fatigue level and quality of life.

METHODS

Sixty-four patients were randomly assigned to either the PR Group (PRGr) or the PR with IMT group (IMTGr). Both groups underwent an 8-week standard PR program, including breathing exercises, muscle strengthening, and walking. Additionally, IMTGr received IMT sessions. Outcome measures comprised six-minute walking distance (6MWD), maximal inspiratory and expiratory pressures (MIP, MEP), peripheral muscle strength, modified Medical Research Council dyspnea score, fatigue symptom scale, spirometric parameters, Saint George Quality of Life Questionnaire (SGRQ), International Physical Activity Questionnaire Short Form (IPAQ-SF), and Hospital Anxiety and Depression Scale.

RESULTS

Our study found no significant difference in exercise capacity improvement between IMTGr and PRGr. However, IMTGr showed significant improvement in MIP compared to PRGr. Both groups experienced improvements in dyspnea, fatigue, and depression scores, as well as enhancements in 6MWD, MEP, peripheral muscle strength, IPAQ-SF and SGRQ scores.

CONCLUSION

Adding IMT to PR did not show a significant difference between groups among BLVR-eligible patients. However, improved respiratory muscle strength may have positive clinical implications. Further research is needed to explore short and long-term effects.

Characteristics of Skeletal Muscle Strength in Subjects With Interstitial Lung Disease

OBJECTIVES

To investigate muscle strength and the prevalence of muscle weakness in adults with interstitial lung diseases (ILDs) compared to healthy subjects.

DESIGN

Cross-sectional (description of clinical features).

SETTING

Public referral center (University Hospital).

PARTICIPANTS

One hundred and twelve adults with ILD (n=48, 60±10yr, 68% female) and healthy counterparts (control group, n=64, 57±10yr, 58% female) (N=112).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE(S)

Muscle strength and prevalence of muscle weakness in adults with ILD. Muscle strength was assessed via maximal isometric voluntary contraction of dominant upper and lower limb muscle groups. Data from the control group were used to generate reference equations. Muscle weakness was defined as a muscle strength value below the lower limit of normal calculated using data from the control group. Data were expressed as mean ± SD or median [interquartile range] according to the data distribution.

RESULTS

Compared to the control group, adults with ILD had lower muscle strength for all muscle groups assessed (values presented as %predicted: pectoralis major 75[57-86]%; quadriceps 72[58-87]%; latissimus dorsi 76[57-103]%; deltoid 74[64-98]%; biceps brachii 78[64-91]%; triceps brachii 84[62-101]%; P≤.001 for all). Prevalence of muscle weakness in people with ILD was 40% for pectoralis major, 25% for latissimus dorsi, 16% for triceps brachii, 20% for biceps brachii, 27% for deltoid and 46% for quadriceps.

CONCLUSIONS

Adults with ILD present a generalised reduction in peripheral Muscle strength, ranging between 20% to 46% of people depending on the muscle group assessed. and it was more prevalent in lower limb muscles.

The impact of sleep duration on physical activity in daily life in patients with idiopathic pulmonary fibrosis

BACKGROUND

Despite the high prevalence of sleep disturbances in idiopathic pulmonary fibrosis (IPF), the relationship between physical activity in daily life (PADL) and sleep in this population remains unclear.

OBJECTIVES

Investigate the impact of sleep on different domains of PADL in IPF and characterize their PADL profile.

METHODS

Sixty-seven participants (thirty-three with IPF and thirty-four healthy subjects [control group]) were included. The subjects underwent assessments of pulmonary function, exercise capacity, respiratory and peripheral muscle strength, PADL, sleep, dyspnea, and health-related quality of life. PADL and sleep measures were assessed using an activity monitor (Actigraph®, wGT3x-BT). Associations between sleep and PADL were done using correlation and regression models.

RESULTS

In the IPF, sleep duration at night associated significantly with step counts, sedentary, light, and moderate-to-vigorous physical activity (MVPA) (-0.82 ≤ R ≤ 0.43; p < .05 for all). Lung function and sleep partially explained PADL variables (0.19 ≤ R2 ≤ 0.65, p < .05 for all). Compared to controls, the IPF subjects presented lower step counts, less time spent in MVPA, standing position, and more time spent in lying position (p < .05, for all).

CONCLUSIONS

Sleep duration is associated with PADL in IPF. The PADL profile of patients is worse than in control subjects.

Effectiveness and mechanism of action of rTMS combined with quadriceps strength training in individuals with knee osteoarthritis: study protocol for a randomized controlled trial

BACKGROUND

Quadriceps training is necessary in function and activity of daily living for patients with knee osteoarthritis (KOA). However, it did not reduce the rate of surgical treatment for end-stage KOA in the long term. This may be related to brain structure changes and maladaptive plasticity in KOA patients. Transcranial Magnetic Stimulation (TMS) could enhance the functional connectivity of brain regions and improves maladaptive plasticity. However, the synergistic effect of the combination of the two for treat KOA is still unclear. Therefore, the purpose of this study is to investigate whether the High-Frequency rTMS combined with quadriceps strength training can improve the pain and function in KOA more effectively than quadriceps training alone and explore the mechanism of action.

METHODS

This study is an assessor-blind, sham-controlled, randomized controlled trial involving 12 weeks of intervention and 6 months follow-up. 148 participants with KOA will receive usual care management and be randomized into four subgroups equally, including quadriceps strength training, high-frequency rTMS training, sham rTMS and quadriceps strength training, high-frequency rTMS and quadriceps strength training. The rehabilitation interventions will be carried out 5 days per week for a total of 12 weeks. All outcomes will be measured at baseline, 4 weeks, 8 weeks, and 12 weeks during the intervention and 1 month, 3 months and 6 months during the follow-up period. The effectiveness outcomes will be included visual analog scale, isokinetic knee muscle strength, Knee Injury and Osteoarthritis Outcome score and 36-Item Short-Form Health Survey score; The act mechanism outcomes will be included motor evoked potential, grey matter density, white matter, subcortical nuclei volumes, cortical thickness and functional connectivity by MRI. Two-way of variance with repeated measures will be used to test the group and time effect for outcome measures.

DISCUSSION

The study will be the first protocol to examine whether there are synergistic effects following high-frequency rTMS combined with quadriceps strength training for treat KOA and clarify the mechanism of action. High-frequency rTMS can be added into the training program for KOA patients if it is proven effective.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2300067617. Registered on Jan.13,2023.

An Update on Outcomes for COPD Pharmacological Trials: A COPD Investigators Report - Reassessment of the 2008 American Thoracic Society/European Respiratory Society Statement on Outcomes for COPD Pharmacological Trials

Background: In 2008, a dedicated American Thoracic Society/European Respiratory Society task force published a paper on the possible use and limitations of clinical outcomes and biomarkers to evaluate the impact of pharmacological therapy in patients with chronic obstructive pulmonary disease. Since then, our scientific understanding of chronic obstructive pulmonary disease has increased considerably; there has been a progressive shift from a one-size-fits-all diagnostic and therapeutic approach to a personalized approach; and many new treatments currently in development will require new endpoints to evaluate their efficacy adequately. Objectives: The emergence of several new relevant outcome measures motivated the authors to review advances in the field and highlight the need to update the content of the original report. Methods: The authors separately created search strategies for the literature, primarily based on their opinions and assessments supported by carefully chosen references. No centralized examination of the literature or uniform criteria for including or excluding evidence were used. Measurements and Main Results: Endpoints, outcomes, and biomarkers have been revisited. The limitations of some of those reported in the American Thoracic Society/European Respiratory Society task force document have been highlighted. In addition, new tools that may be useful, especially in evaluating personalized therapy, have been described. Conclusions: Because the "label-free" treatable traits approach is becoming an important step toward precision medicine, future clinical trials should focus on highly prevalent treatable traits, and this will influence the choice of outcomes and markers to be considered. The use of the new tools, particularly combination endpoints, could help better identify the right patients to be treated with the new drugs.

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. In addition, patients with COPD performed a 6-min walk test (6MWT) and a 1-min sit-to-stand test (1STS). Multiple linear regressions were performed to develop reference equations. The proportion of patients with COPD with reduced quadriceps function was determined, and correlations between quadriceps strength, endurance and power expressed in percentage of predicted values and 6MWT and 1STS performance were used to document the construct validity of the reference equation.

Results

Except for quadriceps isometric endurance, the proposed reference equations explained 50-70% of the variance of the quadriceps properties in healthy individuals. All quadriceps properties were systematically reduced in a large proportion of patients with COPD compared to healthy individuals. Correlation coefficients between quadriceps properties expressed in percentage of predicted values and 6MWT and 1STS performance ranged between 0.28 and 0.49 (all p<0.05).

Conclusion

In healthy individuals, age, sex, height and body mass index explained 50-70% of the variance of quadriceps strength, endurance and power. When expressed in percentage of predicted values, these quadriceps properties correlated with 6MWT and 1STS performance, suggesting construct validity of the reference values in patients with COPD.

Effect on muscle strength after blood flow restriction resistance exercise in early in-patient rehabilitation of post-chronic obstructive pulmonary disease acute exacerbation, a single blinded, randomized controlled study

BACKGROUND

Early commencement of rehabilitation might counteract the loss of muscle strength due to a chronic obstructive pulmonary disease acute exacerbation (COPDAE). Blood flow restriction resistance exercise (BFR-RE) using a low intensity of training load has demonstrated muscle strength gain in varieties of clinical populations. This trial aimed at studying the efficacy and acceptability of BFR-RE in patients with post-COPDAE which was not reported before.

METHOD

A prospective, assessor blinded, randomized controlled study with 2-week in-patient rehabilitation program with BFR-RE was compared to a matched program with resistance exercise without BFR in patients with post-COPDAE. The primary outcome was the change of muscle strength of knee extensor of dominant leg. The secondary outcomes included changes of hand grip strength (HGS), 6-minute walk test (6MWT) distance, short physical performance battery (SPPB) scores, COPD assessment test (CAT) scores; acceptability and feasibility of BFR-RE; and 1-month unplanned re-admission rate.

RESULTS

Forty-Five post-COPDAE patients (mean age = 76 ± 10, mean FEV1%=49% ± 24%) were analyzed. After training, BFR-RE group and control group demonstrated a statistically significant median muscle strength gain of 20 (Interquartile range (IQR) 3 to 38) Newton(N) and 12 (IQR -9 to 30) N respectively. BFR-RE group showed a significant change in SPPB scores, but not in 6MWT distance and HGS after training. Between groups did not have statistically significant different in all primary and secondary outcomes, though with similar acceptability. Drop-out rate due to training-related discomfort in BFR-RE group was 3.7%.

CONCLUSION

BFR-RE is feasible and acceptable in patients with post-COPDAE. A 2-week inpatient pulmonary rehabilitation with BFR-RE improved muscle strength of knee extensors, but not a greater extent than the same rehabilitation program with resistance exercise without BFR. Further studies could be considered with a longer training duration and progression of resistance load. [ClinicalTrials.gov Identifier: NCT04448236].

Use of different reference values for handgrip strength in individuals with COPD: analysis of agreement, discriminative capacity, and main clinical implications

Objective: To identify reference values for handgrip strength through a literature search and compare the agreement of reference values from Brazil with others for handgrip strength in a sample of COPD patients in Brazil, as well as to determine which set of reference values is more discriminative regarding differences in clinical characteristics between individuals with low handgrip strength and normal handgrip strength. Methods: To identify reference values for handgrip strength, a literature search was performed; a retrospective cross-sectional analysis of baseline-only data from two unrelated studies was then performed. Individuals were evaluated for handgrip strength, peripheral muscle strength, respiratory muscle strength, pulmonary function, body composition, exercise capacity, dyspnea, and functional status. Results: Of the 45 studies that were initially selected, 9 met the criteria for inclusion in the analysis, which included 99 COPD patients in Brazil (52% of whom were male with GOLD stage II-IV COPD). The prevalence of low handgrip strength varied across studies (from 9% to 55%), the set of reference values for handgrip strength in a sample of individuals in Brazil having classified 9% of the study sample as having low handgrip strength. The level of agreement between the reference values for a sample of individuals in Brazil and the other sets of reference values varied from weak to excellent. The reference values for a sample of individuals in Brazil showed the highest number of significantly different characteristics between individuals with low and normal handgrip strength. Conclusions: The level of agreement between national and international sets of reference values for handgrip strength varied from weak to excellent in COPD patients in Brazil. Reference values for handgrip strength with higher discriminative capacity are not necessarily those that identify more individuals as having low handgrip strength.

Predictors and changes of physical activity in idiopathic pulmonary fibrosis

Background

Different clinical predictors of physical activity (PA) have been described in idiopathic pulmonary fibrosis (IPF), but studies are lacking evaluating the potential role of muscle strength and anxiety and depression symptoms in PA limitation. Moreover, little is known about the impact of changes in PA in the course of the disease. The aim of the present study was to investigate the relationship between baseline PA and a wide range of variables in IPF, to assess its longitudinal changes at 12 months and its impact on progression free-survival.

Methods

PA was assessed by accelerometer and physiological, clinical, psychological factors and health-related quality of life were evaluated in subjects with IPF at baseline and at 12 month follow-up. Predictors of PA were determined at baseline, evolution of PA parameters was described and the prognostic role of PA evolution was also established.

Results

Forty participants with IPF were included and 22 completed the follow-up. At baseline, subjects performed 5765 (3442) daily steps and spent 64 (44) minutes/day in moderate to vigorous PA. Multivariate regression models showed that at baseline, a lower six-minute walked distance, lower quadriceps strength (QMVC), and a higher depression score in the Hospital Anxiety and Depression scale were associated to lower daily step number. In addition, being in (Gender-Age-Physiology) GAP III stage, having a BMI ≥ 25 kg/m² and lower QMVC or maximum inspiratory pressure were factors associated with sedentary behaviour. Adjusted for age, gender and forced vital capacity (FVC) (%pred.) a lower progression-free survival was evidenced in those subjects that decreased PA compared to those that maintained, or even increased it, at 12 months [HR 12.1 (95% CI, 1.9–78.8); p = 0.009].

Conclusion

Among a wide range of variables, muscle strength and depression symptoms have a predominant role in PA in IPF patients. Daily PA behaviour and its evolution should be considered in IPF clinical assessment and as a potential complementary indicator of disease prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02134-4.

Effects of Carbohydrate and Protein Administration by Food Items on Strength Response after Training in Stable COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is one of the world's most common diseases and reasons for death. Systemic consequences, especially reduced muscle strength, muscle mass and muscle function, are common and contribute to worsening prognosis and increasing morbidity and mortality. There is strong evidence that physical activity and strength training are effective in prolonging life and lead to better quality of life. Numerous studies have shown that ingestion of protein and carbohydrates after strength training can increase regeneration of strength in young athletes. Recently, we demonstrated that the same effect can be achieved with these macronutrients administered in a meal. Until now, it is not clear if patients with COPD, integrated in regular physical training, respond similarly.

METHODS

Prescribed strength training, consisting of two sets circular training with machines for big muscle groups was supplemented with a meal rich in protein and carbohydrates. Changes in maximum strength after 24 h were investigated to find out about the impact of this meal on physical capacity. A pilot study was conducted with pragmatic cross-over design.

RESULTS

With nutritive intervention, strength in both knee extensor and chest press were significantly higher than in control training.

CONCLUSION

The study showed beneficial effects for the intake of protein and carbohydrates in changes in maximum strength. For now, the underlying mechanism remains unclear. Clinical relevance needs further research. The study design and study protocol can be used for further studies with only small adaptions.

Minimal important difference of two methods for assessment of quadriceps femoris strength post exercise program in individuals with COPD

BACKGROUND

The assessment of quadriceps femoris (QF) strength is recommended by international guidelines as an outcome of exercise training (ET) programs in patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To identify the minimal important difference (MID) of two methods for the assessment of improvement of QF strength after a high-intensity ET program in individuals with COPD: 1-repetition maximum (1RM) and maximal voluntary contraction (MVC).

METHODS

Individuals with moderate to very-severe stable COPD were submitted to high-intensity ET (3 days/week, 36 sessions). Lung function (spirometry), exercise capacity (6-minute walk test [6MWT]) and QF strength (1RM test and MVC by using a strain-gauge) were assessed before and after the ET program.

RESULTS

Twenty-one individuals were studied (65±8 years, BMI 27±6; FEV₁ 51±16%predicted). At the end of the ET program, QF strength improved significantly (10±4 Nm for MVC and 8 ± 6 kg for 1RM) (P<0.05 for both). The MID for improvement of the QF strength calculated by distribution-based methods ranged from 9.4 to 16 Nm (between 7.4% and 12.6% increase from baseline) for the MVC and from 2.5 to 3 kg (between 12% and 15% increase from baseline) for the 1RM test. Anchor-based MIDs could not be calculated since there was no correlation between the improvement of QF strength and the improvement of the proposed anchor (6MWT).

CONCLUSIONS

The MID for improvement of QF strength after a high-intensity ET program in individuals with moderate-to-severe stable COPD ranges between 9.4 and 16 Nm for the MVC assessed with a strain gauge and between 2.5 and 3 kg for the 1RM test.

Associations Between Lower Limb Isometric Torque, Isokinetic Torque, and Explosive Force With Phases of Reactive Stepping in Young, Healthy Adults

This study aimed to determine the relationship between lower limb muscle strength and explosive force with force plate-derived timing measures of reactive stepping. Nineteen young, healthy adults responded to 6 perturbations using an anterior lean-and-release system. Foot-off, swing, and restabilization times were estimated from force plates. Peak isokinetic torque, isometric torque, and explosive force of the knee extensors/flexors and plantar/dorsiflexors were measured using isokinetic dynamometry. Correlations were run based on a priori hypotheses and corrected for the number of comparisons (Bonferroni) for each variable. Knee extensor explosive force was negatively correlated with swing time (r = -.582, P = .009). Knee flexor peak isometric torque also showed a negative association with restabilization time (r = -.459, P = .048); however, this was not statistically significant after correcting for multiple comparisons. There was no significant relationship between foot-off time and knee or plantar flexor explosive force (P > .025). These findings suggest that there may be utility to identifying specific aspects of reactive step timing when studying the relationship between muscle strength and reactive balance control. Exercise training aimed at improving falls risk should consider targeting specific aspects of muscle strength depending on specific deficits in reactive stepping.

From Inception to Implementation: Strategies for Setting Up Pulmonary Telerehabilitation

Background

The emergence of innovative technology-enabled models of care is an opportunity to support more efficient ways of organizing and delivering healthcare services and improve the patient experience. Pulmonary telerehabilitation started as a promising area of research and became a strategic pandemic response to patients' decreased accessibility to rehabilitation care. Still, in the pre-COVID-19 era, we conducted a participatory study aiming to develop strategies for setting up pulmonary telerehabilitation as a person-centered digitally-enabled model of care.

Methods

We performed operational participatory research between June 2019 and March 2020 with the engagement of all stakeholders involved in the implementation of pulmonary telerehabilitation, including 14 people with Chronic Obstructive Pulmonary Disease. Patients were assessed subjectively and objectively pre and post a 3-month pulmonary rehabilitation program including exercise and education, which started in a face-to-face hospital setting during the first month and continued as a home-based, remotely supervised exercise training intervention.

Results

Five major groups of requirements targeted operational strategies for setting up pulmonary telerehabilitation: (1) pulmonary rehabilitation core principles, (2) quality and security standards, (3) technological functionality, (4) home environment appropriateness, and (5) telesetting skills. There was a statistical significance in the median change in the CAT score from 15.5 to 10.5 (p = 0.004) and in the PRAISE score from 49.5 to 53.0 (p = 0.006). Patients' mean levels of satisfaction regarding rehabilitation goals achievements were 88.1 ± 8.6% and the mean levels of satisfaction regarding the telerehabilitation experienced as a model of care were 95.4% ± 6.3%.

Conclusions

The success of telerehabilitation implementation was grounded on stakeholder engagement and targeted strategies for specific setup requirements, achieving patients' high satisfaction levels. Such operational experiences should be integrated into the redesigning of upgraded telerehabilitation programs as part of the solution to improve the effectiveness, accessibility, and resilience of health systems worldwide.

Exercise Training in Post-COVID-19 Patients: The Need for a Multifactorial Protocol for a Multifactorial Pathophysiology

The battle against COVID-19 has entered a new phase with Rehabilitation Centres being among the major players, because the medical outcome of COVID-19 patients does not end with the control of pulmonary inflammation marked by a negative virology test, as many patients continue to suffer from long-COVID-19 syndrome. Exercise training is known to be highly valuable in patients with cardiac or lung disease, and it exerts beneficial effects on the immune system and inflammation. We therefore reviewed past and recent papers about exercise training, considering the multifactorial features characterizing post-COVID-19 patients’ clinical conditions. Consequently, we conceived a proposal for a post-COVID-19 patient exercise protocol as a combination of multiple recommended exercise training regimens. Specifically, we built pre-evaluation and exercise training for post-COVID-19 patients taking advantage of the various programs of exercise already validated for diseases that may share pathophysiological and clinical characteristics with long-COVID-19.

Effect of a postoperative home-based exercise and self-management programme on physical function in people with lung cancer (CAPACITY): protocol for a randomised controlled trial

INTRODUCTION

Exercise is important in the postoperative management of lung cancer, yet no strong evidence exists for delivery of home-based programmes. Our feasibility (phase I) study established feasibility of a home-based exercise and self-management programme (the programme) delivered postoperatively. This efficacy (phase II) study aims to determine whether the programme, compared with usual care, is effective in improving physical function (primary outcome) in patients after lung cancer surgery.

METHODS AND ANALYSIS

This will be a prospective, multisite, two-arm parallel 1:1, randomised controlled superiority trial with assessors blinded to group allocation. 112 participants scheduled for surgery for lung cancer will be recruited and randomised to usual care (no exercise programme) or, usual care plus the 12-week programme. The primary outcome is physical function measured with the EORTC QLQ c30 questionnaire. Secondary outcomes include health-related quality of life (HRQoL); exercise capacity; muscle strength; physical activity levels and patient reported outcomes. HRQoL and patient-reported outcomes will be measured to 12 months, and survival to 5 years. In a substudy, patient experience interviews will be conducted in a subgroup of intervention participants.

ETHICS AND DISSEMINATION

Ethics approval was gained from all sites. Results will be submitted for publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12617001283369.

Impact of high-flow oxygen therapy during exercise in idiopathic pulmonary fibrosis: a pilot crossover clinical trial

BACKGROUND

Supplemental oxygen delivered with standard oxygen therapy (SOT) improves exercise capacity in patients with idiopathic pulmonary fibrosis (IPF). Although high-flow nasal cannula oxygen therapy (HFNC) improves oxygenation in other respiratory diseases, its impact on exercise performance has never been evaluated in IPF patients. We hypothesized that HFNC may improve exercise capacity in IPF subjects compared to SOT.

METHODS

This was a prospective, crossover, pilot randomized trial that compared both oxygenation methods during a constant submaximal cardiopulmonary exercise test (CPET) in IPF patients with exertional oxygen saturation (SpO₂) ≤ 85% in the 6-min walking test. The primary outcome was endurance time (Tlim). Secondary outcomes were muscle oxygen saturation (StO₂) and respiratory and leg symptoms.

RESULTS

Ten IPF patients [71.7 (6) years old, 90% males] were included. FVC and DL_CO were 58 ± 11% and 31 ± 13% pred. respectively. Tlim during CPET was significantly greater using HFNC compared to SOT [494 ± 173 vs. 381 ± 137 s, p = 0.01]. HFNC also associated with a higher increase in inspiratory capacity (IC) [19.4 ± 14.2 vs. 7.1 ± 8.9%, respectively; p = 0.04], and a similar trend was observed in StO₂ during exercise. No differences were found in respiratory or leg symptoms between the two oxygen devices.

CONCLUSIONS

This is the first study demonstrating that HFNC oxygen therapy improves exercise tolerance better than SOT in IPF patients with exertional desaturation. This might be explained by changes in ventilatory mechanics and muscle oxygenation. Further and larger studies are needed to confirm the benefits of HFNC in IPF patients and its potential usefulness in rehabilitation programs.

Isolated Resistance Training Programs to Improve Peripheral Muscle Function in Outpatients with Chronic Obstructive Pulmonary Diseases: A Systematic Review

This systematic review aims to establish which isolated resistance training (RT) programs have been used in outpatients with chronic obstructive pulmonary disease (COPD) and their impact on all aspects of peripheral skeletal muscle function. Electronic databases were systematically searched up to June 2021. The eligibility criteria were: (1) randomized controlled trials investigating the effects of supervised and isolated RT programs in outpatients with COPD and (2) RT programs lasting 8-12 weeks, (3) including at least one outcome measure related to trainable muscle characteristics. Initially, 6576 studies were identified, whereas 15 trials met the inclusion criteria. All the included trials reported that isolated RT improved both upper and lower limbs' maximal strength. Muscle endurance and power also increased after RT but received less attention in the analysis. Furthermore, few studies assessed the effect of RT on muscle mass and cross-sectional area, reporting only limited improvement. Isolated RT programs carried out 2-3 days a week for 8-12 weeks improved skeletal muscle function in individuals with COPD. The RT program should be specifically focused to the trainable muscle characteristic to be improved. For this reason, we further encourage the introduction of a detailed assessment of muscle function and structure during the pulmonary rehabilitation practice.

Reliability of Quadriceps Femoris Muscle Strength Assessment Using a Portable Dynamometer and Protocol Tolerance in Patients With Chronic Obstructive Pulmonary Disease

OBJECTIVE

This study aimed to evaluate the intrarater and interrater reliability of isometric quadriceps strength (IQS) using a portable dynamometer in individuals with chronic obstructive pulmonary disease (COPD) and to verify their tolerance to the protocol.

METHODS

A cross-sectional reliability study was conducted with 50 individuals with stable COPD (34 men and 16 women; mean age = 70 years [SD = 8]). The main outcome measure was obtained using a portable dynamometer (Microfet 2) to assess IQS. Two masked raters performed 2 assessments in the dominant lower limb on 2 nonconsecutive days. The intraclass correlation coefficient (ICC) was used to verify the intrarater and interrater reliability and was considered excellent when >0.90, with a 5% significance level.

RESULTS

Rater 1 and 2 intrarater reliability was as follows: ICC = 0.96 (95% CI = 0.94 to 0.98) and ICC = 0.97 (95% CI = 0.95 to 0.98), respectively. The interrater reliability was as follows: ICC = 0.96 (95% CI = 0.93 to 0.98). The minimum detectable difference was 4 to 5 peak isometric strength, in mean, for intrarater and interrater reliability. Not all patients presented relevant changes in physiological responses, dyspnea, and lower limb fatigue.

CONCLUSION

There was an excellent intrarater and interrater reliability for IQS, and the participants tolerated the protocol.

IMPACT

This tool can be used to assess quadriceps strength in clinical practice in patients with COPD.

Handgrip Strength as a Reflection of General Muscle Strength in Chronic Obstructive Pulmonary Disease

Muscle dysfunction is one of the main features in individuals with chronic obstructive pulmonary disease (COPD). Handgrip strength (HS) has been used as a representation of general muscle strength in various populations, and a few studies found correlation between HS and other measures of upper and lower limbs' muscle strength in the general population, although this was not yet studied in depth in COPD. The aims of this study were to verify if HS is cross-sectionally well correlated with upper and lower limbs' muscle strength in individuals with COPD, and to identify a new cutoff for handgrip weakness in this population. HS was assessed by a dynamometer, whereas other muscle strength assessments comprised maximal voluntary contraction (MVC) of the quadriceps femoris and 1-repetition maximum (1RM) of biceps and triceps brachii, pectoralis major, latissimus dorsi and quadriceps femoris. Additional assessments included pulmonary function and volumes, body composition and exercise capacity. Fifty individuals with COPD were studied (65 ± 7 years; FEV₁ 51 ± 14%pred). HS showed moderate-to-strong correlations with all 1-RM assessments (0.62<r < 0.75) and especially with MVC of the quadriceps femoris (r = 0.83) (p < 0.05 for all). Correlations were stronger for male than female individuals, and the assessment performed on right, left or dominant hand did not present significant differences. A cutoff of 0.3892 for HS/weight yielded an AUC = 0.90 to identify weakness. In conclusion, HS is a good reflection of upper and lower limbs' muscle strength in individuals with COPD. Its usefulness as a surrogate for more complex assessments must be based on the settings and conditions.

Functional performance tests in interstitial lung disease: Impairment and measurement properties

BACKGROUND

There is limited information regarding impairment in functional performance tests and their measurement properties in ILD. The present study aimed to verify the impairment and measurement properties of functional performance tests in ILD.

METHODS

ILD and healthy individuals underwent assessments of pulmonary function, peripheral muscle strength (handgrip force and maximum isometric contraction of quadriceps femoris - MIVCq) and exercise capacity (6-min walk test - 6MWT). Functional performance was assessed by timed-up-and-go with usual (TUGu) and fast (TUGf) gait speeds, 4-m gait speed (4MGS), sit-to-stand in 30 s (30sec-STS), 1 min (1min-STS) and with 5 repetition (5rep-STS) and Short Physical Performance Battery (SPPB). Functional performance was compared between groups, validity (correlation with 6MWT and MIVCq) and reliability of tests were checked in subjects with ILD (intra- and inter-rater agreement analysis).

RESULTS

Seventy-six participants (40 ILD [25 women, 61 ± 11 years, FVC 75 ± 17 %pred] and 36 healthy [22 women, 61 ± 9 years, FVC 97 ± 11 %pred]) were included. Functional performance in ILD was worse than in healthy individuals in all tests, except for the 30sec-STS (p = 0.13). Pre-specified validity criteria were reached for TUGu, TUGf, 4MGS and 5rep-STS (-0.69 < r < 0.55; p < 0.05 for all). Except for 4MGS and SPPB, all tests showed good to excellent inter-rater (0.85 < ICC<0.93; p < 0.05 for all) and all tests showed good to excellent intra-rater (0.83 < ICC< 0.94; p < 0.05 for all) reliability.

CONCLUSIONS

Subjects with ILD present worse functional performance than healthy individuals. According to reliability and validity results, TUGu, TUGf and 5rep-STS seem to be the most appropriate tests to evaluate functional performance in ILD.

[Which physical tests for which objectives in pulmonary rehabilitation?]

Chronic respiratory disease is a major cause of morbidity and mortality worldwide and an important cause of disability including a reduction of exercise, functional and muscle capacity contributing to a decreased quality of life. In the context of pulmonary rehabilitation, a thorough patient-centered outcome assessment, including not only measures of lung function, but also exercise functional and muscle capacity, is imperative for a comprehensive disease management. Assessment of these impairments and dysfunctions with appropriate and change-sensitive procedures is thus necessary for personalizing the physical interventions and assessing the short- and long-term effectiveness of the intervention. The clinician currently has a wide variety of tests and measurements available to assess the physical and functional capacity of people with chronic respiratory disease. The aim of this review is to provide a pragmatic synthesis of the physical, functional and muscle capacity tests most commonly used in pulmonary rehabilitation. Ultimately, it should help the clinician to identify the relevant evaluations according to the objectives of the patients but also according to the available resources, the setting of pulmonary rehabilitation and the specific qualities of each test.

Are there differences in muscular activation to maintain balance between individuals with chronic obstructive pulmonary disease and controls?

BACKGROUND

The mechanisms underlying impaired balance in chronic obstructive pulmonary disease (COPD) are poorly understood, which makes it difficult to choose the best therapeutic approaches. Therefore, this study aimed to investigate patterns of muscular activation to maintain balance and its determinants in this population.

METHODS

Thirty-three subjects with COPD and 33 controls were assessed by a force platform in four tasks: standing with eyes opened (FHEO) and closed (FHEC); standing on unstable surface (SUS) and one-legged stance (OLS). Electromyographic activity of lower limb, trunk and neck muscles was concomitantly recorded. To asses functional balance, Brief-balance evaluation systems and timed up & go (TUG) tests were applied. Lung function, exercise capacity and muscle force were also assessed.

RESULTS

Subjects with COPD presented worse balance and higher scalene activation than controls in OLS (mean difference 23.0 [95%CI 1.7-44.3] _%Δ μV_RMS; P = 0.034), besides presenting also higher activation of gluteus medius during FHEC task (mean difference 1.5 [95%CI 0.2-2.8] _%Δ μV_RMS; P = 0.023) and taking longer to complete the TUG (mean difference 0.6 [95%CI 0.1-1.2] seconds; P = 0.042). Exercise capacity and peripheral muscle force were determinants of functional balance (r² = 0.505), whereas age (OR = 1.24; 95%CI 1.02-1.52) and total lung capacity (OR = 2.42; 95%CI 1.05-5.56) were determinants of static balance.

CONCLUSION

Individuals with COPD have worse static and functional balance in comparison with controls, besides presenting higher activation of scalene and gluteus medius during static balance tasks. Exercise capacity and peripheral muscle force emerged as determinants of functional balance, whereas age and lung hyperinflation contributed to poor static balance.

The role of peripheral muscle fatigability on exercise intolerance in COPD

INTRODUCTION

Exercise limitation in chronic obstructive pulmonary disease (COPD) is multi-factorial; however, growing evidence indicates that muscle dysfunction may contribute in some patients.

AREAS COVERED

This work outlines current evidence for and against increased peripheral muscle fatigability in COPD through a comprehensive review of relevant literature available on PubMed/MEDLINE until May 2020. The authors first discuss key methodological issues relative to muscle fatigue assessment by non-volitional techniques, particularly magnetic stimulation. The authors then provide a detailed discussion of critical studies to have objectively measured skeletal muscle fatigue in individuals with COPD.

EXPERT OPINION

Current evidence indicates that localized (knee extension) and cycling exercise are associated with increased quadriceps fatigability in most COPD patients. Increased fatigability, however, has not been consistently found in response to walking, likely reflecting the tendency of 'central' respiratory constraints to overshadow potential functional impairments in the appendicular muscles in this form of exercise. Thus, addressing skeletal muscle abnormalities may be critical to translate improvements in lung mechanics (e.g., due to bronchodilator therapy) into better exercise tolerance. The positive effects of pulmonary rehabilitation on muscle fatigability are particularly encouraging and suggest a role for these measurements to test the efficacy of emerging adjunct training strategies focused on the peripheral muscles.

Test-Retest Reliability of Handgrip Strength in Patients with Chronic Obstructive Pulmonary Disease

The purpose of this study was to investigate the intra-rater reliability and agreement of handgrip strength (HGS) measurement using a hydraulic hand dynamometer in patients with chronic obstructive pulmonary disease (COPD). A sample of 19 COPD patients (18 males and 1 female; mean ± SD age, 66.9 ± 6.3 years) was evaluated using a hand dynamometer by the same rater in two different testing sessions with a 7-d interval. During each session, patients were asked to exert three maximal isometric contractions on the dominant hand and the mean value of the 3 efforts (measured in kilogram-force [Kgf]) was used for data analysis. The intraclass correlation coefficient (ICC_2,1), the standard error of measurement (SEM), the minimal detectable change (MDC), and Bland-Altman methods were used to estimate the degree of test-retest reliability and the measurement error, respectively. HGS in COPD patients revealed an ICC_2,1 score of 0.99, suggesting excellent test-retest reliability. The calculated SEM was relatively small (0.59 Kgf), and the MDC presented a clinically acceptable value of 1.64 Kgf. These findings, in conjunction with the narrow width of the 95% limits of agreements (95% limits of agreement, -2.5-2.1 Kgf) in the Bland-Altman plot, reflected the measurement precision and the narrow variation of the differences during the 2 testing sessions. The results of this study demonstrated an excellent test-retest reliability of HGS measurement, indicating that this method is reliable for repeated monitoring of peripheral muscle strength in patients with COPD.

Impaired knee extension muscle strength in adolescents but not in children with Fontan circulation

INTRODUCTION

Impaired isometric muscle strength was previously reported in adults with Fontan circulation. However, it is unclear if this impairment is present in children and adolescents with Fontan circulation. We investigated isometric muscle strength of the lower limb in patients (6-18 years) with Fontan circulation in comparison with healthy controls.

METHOD

In this cross-sectional study, 43 patients (6-18 years) with Fontan circulation and 43 age- and sex-matched controls were included. Isometric knee extension and plantar flexion muscle strength were assessed using dynamometry (Newton, N). Lean mass of the legs was assessed with dual-energy X-ray absorptiometry. Analyses were performed on group level (n = 43), and for subgroups that included children aged 6-12 years (n = 18) and adolescents aged 13-18 years (n = 25).

RESULTS

On group level, the patients with Fontan circulation had impaired isometric knee extension strength in comparison with the controls (p = 0.03). In subgroup analyses, impaired isometric knee extension strength was present in the adolescents (p = 0.009) but not in the children groups. For plantar flexion, there was no difference between patients and controls. There was no difference in lean mass between patients and controls (9.6 ± 4.3 kg vs. 10.8 ± 5.6 kg, p = 0.31). However, the lean mass was highly correlated to isometric knee extension strength (patients r = 0.89, controls r = 0.96, p < 0.001) and isometric plantar flexion strength (patients r = 0.7, controls r = 0.81, p < 0.001).

CONCLUSION

The finding of impaired isometric knee extension muscle strength in adolescents (13-18 years) with Fontan circulation and no corresponding impairment in the children group (6-12 years) could imply that isometric muscle strength gets more impaired with age.

Clinimetric evaluation of muscle function tests for individuals with cystic fibrosis: A systematic review

Accurate testing of muscle function is essential in individuals with cystic fibrosis (CF). A literature search was conducted in MEDLINE, CENTRAL, CINAHL, PEDro, ScienceDirect and Web of Science according to PRISMA and COSMIN guidelines from inception to September 2019 to investigate the clinimetric properties of muscle tests in individuals with CF. The search identified 37 studies (1310 individuals) and 34 different muscle tests. Maximal inspiratory pressure, inspiratory work capacity and quadriceps strength measured by computerised dynamometry were identified as reliable tests of muscle function. The one-minute sit-to-stand test was found to have high reliability but its validity to measure quadriceps strength is unknown. The clinimetric properties of other routinely used tests have not been reported in people with CF. Very different measurement procedures were identified. Inspiratory muscle and quadriceps testing can be considered as reliable but high-quality studies evaluating tests of other muscles function (e.g. muscle endurance) are lacking.

Cluster analysis identifying patients with COPD at high risk of 2-year all-cause mortality

The objective of the article is to identify clusters of patients with COPD according to factors known to be associated with mortality and to verify whether clusters' assignment is associated with 2-year mortality. Patients ( n = 141) were evaluated by bioelectrical impedance, maximal inspiratory pressure (MIP), one-repetition maximum test of the quadriceps femoris (1RMQF) and BODE index (body mass index; airflow obstruction (spirometry); dyspnea (modified Medical Research Council scale); and exercise capacity (6-minute walk test (6MWT) distance). Vital status was retrospectively checked 2 years after the assessments, and time to death was quantified for those deceased in this period. K-means analysis identified two clusters. Patients in cluster one (CL I, n = 69) presented an impaired clinical status in comparison to cluster two (CL II, n = 72). Receiver operating characteristics curves identified the cutoffs discriminating patients composing CL I: forced expiratory volume in the first second <44%pred; 6MWT <479 m; 1RMQF <19 kg; and maximum inspiratory pressures <73 cmH₂O (area under the curve range 0.750-0.857). During the follow-up, 19 (13%) patients deceased, 15 in CL I (22%) and 4 in CL II (0.06%) ( p = 0.005). CL I was associated with a higher risk of 2-year mortality (hazard ratio (95% confidence interval): 4.3 (1.40-12.9), p = 0.01). A cluster of patients with COPD highly associated with 2-year mortality was statistically identified, and cutoffs to identify these subjects were provided.

Effects of land- and water-based exercise programmes on postural balance in individuals with COPD: additional results from a randomised clinical trial

OBJECTIVE

To investigate the effects of water-based exercise training on postural balance in individuals with chronic obstructive pulmonary disease (COPD), and compare the effects of two similar protocols of land- and water-based exercise programmes on postural balance in this population.

DESIGN

Randomised clinical trial.

SETTING

University-based, outpatient, physical therapy clinic.

SUBJECTS

Fifty individuals with COPD.

INTERVENTIONS

Participants were assigned at random to the land group (LG; n=27) or the water group (WG; n=23), and underwent high-intensity endurance and strength training three times per week for 3months.

MAIN OUTCOME MEASURES

Functional balance was assessed by the timed up and go test (TUG), and static balance was assessed with a force platform in the following conditions: standing with feet hip-width apart and eyes open; standing with feet hip-width apart and eyes closed; standing on a short base; and one-legged stance.

RESULTS

Seventeen subjects completed the intervention in the LG {nine males, mean age 64 [standard deviation (SD) 8] years, mean forced expiratory volume in 1 second (FEV₁) 48 (SD 17) %predicted} compared with 14 subjects in the WG [nine males, mean age 65 (SD 8) years, FEV₁ 51 (SD 15) %predicted]. Water-based exercise training had a positive effect on functional balance [TUG: mean difference -1.17 (-1.93 to -0.41 95% confidence interval) seconds; P=0.006], whereas static balance remained unaltered for both groups. There was no between-group difference in postural balance after exercise training; however, a higher proportion of participants who had a clinically relevant improvement in the TUG were in the WG (LG 35%, WG 64%; P<0.001).

CONCLUSION

Functional balance improved after 3months of high-intensity exercise training performed in water. Despite the environment, non-specific training seems to be insufficient to improve static balance.

CLINICAL TRIAL REGISTRATION NUMBER

clinicalTrials.gov NCT01691131.

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

Background: 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.Objectives: 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.Design/Setting: Prospective observational study in four Canadian research labs.Participants: People with mild to very severe COPD.Methods: Tests were conducted on two days. Quadriceps muscle maximal strength was evaluated during a static maneuver using maximal voluntary isometric contractions (MVIC). Rate of torque development (RTD) during MVIC was used to assess explosive force. Muscle power was measured using a dynamic, isotonic protocol from which peak and average power and peak velocity were derived. Functional capacity was assessed with the Short Physical Performance Battery (SPPB). Reliability was assessed using intraclass correlation coefficients (ICC), standard error of measurements (SEM), and Bland Altman plots. Spearman and Pearson correlation coefficients were used for associations.Results: 65 patients (age 69 ± 8 years; FEV₁ 48 ± 21% of predicted) were included. ICC was 0.77 for RTD and 0.87-0.98 for isotonic power measures (95%CI 0.63-0.99, p < .001); SEM < 10% for average/peak power and peak velocity, and > 30% for RTD. SPPB had moderate correlation with average power, but not with MVIC or RTD.Conclusion: The standardized isotonic protocol with computerized dynamometry was reliable in assessing quadriceps power in COPD. Our data highlights that average power correlates best with functional capacity, indicating higher relevance than static measures when investigating determinants of function.

Evaluation of isokinetic muscle strength of upper limb and the relationship with pulmonary function and respiratory muscle strength in stable COPD patients

Background

Upper limb muscle strength plays an important role in respiratory and pulmonary function, and limited research focuses on the role of strength and endurance of the elbow extensor and flexor. This study was conducted to accurately assess upper limb muscle function and quantified associations with pulmonary function and respiratory muscle strength in patients with stable chronic obstructive pulmonary disease (COPD).

Methods

In this cross-sectional study, patients with stable COPD treated in Yue-Yang Integrative Medicine Hospital from March 2014 to March 2016 were recruited. All participants underwent a pulmonary function test (forced expiratory volume in first second/forced vital capacity, FEV1/FVC; percentage value of predicted FEV1, FEV1%pred), a respiratory muscle strength test (maximal inspiratory pressure, MIP; maximal expiratory pressure, MEP), and an isokinetic test of dominant upper limb after a 24-hr interval (peak torque, PT; PT/body weight, PT/BW; total work, TW; endurance ratio, ER).

Results

A total of 88 patients with stable COPD (age: 65.5±8.7 years) were recruited, of which 73% (64 patients) were male. In the multiple stepwise regression analysis, sex remained as significant impactors in the final model for FEV1%pred (adjusted R²=0.243, P<0.001). Elbow flexor PT/BW and ER, sex, and BMI remained as significant impactors in the final model for FEV1/FVC (adjusted R²=0.255, P<0.01). Elbow flexor TW remained as significant impactors for MIP (adjusted R²=0.112, P=0.001), while elbow extensor PT and PT/BW and sex remained as significant impactors for MEP (adjusted R =0.385, P<0.01).

Conclusion

In stable COPD, pulmonary function and respiratory muscle strength are associated with upper limb muscle strength. In particular, elbow flexor endurance is likely an important impactor for pulmonary function and inspiratory muscle strength, while elbow extensor strength is of importance for expiratory muscle strength.

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.

DESIGN

This was a prospective, observational, multicenter trial.

METHODS

Participants with mild to severe COPD from 4 Canadian sites were tested on 2 separate days. Five iMVCquad measurements were obtained following a standardized procedure with a fixed handheld dynamometer (iMVCquad-HHD), and then 5 iMVCquad measurements were obtained with a computerized dynamometer (iMVCquad-CD; the gold standard). Functional capacity was assessed with the Short Physical Performance Battery. Intraclass correlation coefficients, standard errors of measurement, Bland-Altman plots, and Spearman correlation coefficients were used for analyses.

RESULTS

Sixty-five participants (mean age = 69 years [SD = 8]; forced expiratory volume in 1 second = 48% of predicted value [SD = 21]) completed the study. The mean iMVCquad-HHD values on visits 1 and 2 were 102.7 (SD = 51.6) and 105.6 (SD = 58.8) N·m, respectively; the standard error of measurement was 11.4 N·m. The between-visits intraclass correlation coefficient for iMVCquad-HHD was 0.95 (95% confidence interval  = 0.92-0.97), with a mean bias of 2.0 (Bland-Altman plot). There was a strong correlation between iMVCquad-HHD and iMVCquad-CD (Spearman correlation coefficient = 0.86). There was no correlation between iMVCquad-HHD and Short Physical Performance Battery total score.

LIMITATIONS

Participants had stable COPD with few comorbidities and were more physically active than the general population of people with COPD; results might not be applicable to patients with acute exacerbations of the disease or more comorbidities. Assessment order between handheld and computerized dynamometers has not been randomized, but analyses did not highlight any systematic bias or learning effect.

CONCLUSIONS

Quadriceps strength assessment can be implemented in a reliable and valid way in people with COPD using a fixed handheld dynamometer and standardized procedure. This protocol should be established in clinical practice to facilitate the assessment of muscle strength in people with COPD.

Measuring and monitoring skeletal muscle function in COPD: current perspectives

Skeletal muscle dysfunction is an important systemic consequence of chronic obstructive pulmonary disease (COPD) that worsens the natural cause of the disease. Up to a third of all people with COPD express some form of impairment which encompasses reductions in strength and endurance, as well as an increased fatigability. Considering this complexity, no single test could be used to measure and monitor all aspects of the impaired skeletal muscle function within the COPD population, resulting in a wide range of available tests and measurement techniques. The aim of the current review is to highlight current and new perspectives relevant to skeletal muscle function measurements within the COPD population in order to provide guidance for researchers as well as for clinicians. First of all, standardized and clinically feasible measurement protocols, as well as normative values and predictive equations across the spectrum of impaired function in COPD, are needed before assessment of skeletal muscle function can become a reality in clinical praxis. This should minimally target the quadriceps muscle; however, depending on the objective of measurements, eg, to determine upper limb muscle function or walking capacity, other muscles could also be tested. Furthermore, even though muscle strength measurements are important, current evidence suggests that other aspects, such as the endurance and power capacity of the muscle, should also be considered. Moreover, although static (isometric) measurements have been favored, dynamic measurements of skeletal muscle function should not be neglected as they, in a larger extent than static measurements, are related to tasks of daily living. Lastly, the often modest relationships between functional tests and skeletal muscle function measurements indicate that they evaluate different constructs and thus cannot replace one another. Therefore, for accurate measurements of skeletal muscle function in people with COPD, specific and formal measurements should still be prioritized.

Ventilation distribution, pulmonary diffusion and peripheral muscle endurance as determinants of exercise intolerance in elderly patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a progressive and disabling disease that has been associated with aging. Several factors may potentially impair performance during exercise in elderly patients with COPD. This study was conducted to evaluate what characteristics related to lung function, peripheral muscle strength and endurance can predict the performance of elderly patients with COPD during cardiopulmonary exercise testing (CPET). Forty elderly patients with COPD underwent resting lung function tests, knee isokinetic dynamometry, and CPET. Three models were developed to explain the variability in peak oxygen uptake (VO(2) peak) after controlling for age as an independent confounder. The pulmonary function model showed the highest explained variance (65.6 %); in this model, ventilation distribution (p<0.001) and pulmonary diffusion (0.013) were found to be independent predictors. Finally, the models that included the muscle strength and endurance variables presented explained variances of 51 % and 57.4 %, respectively. In these models that involved muscular dysfunction, however, only the endurance variables were found to be independent predictors (p<0.05). In conclusion, ventilation distribution and pulmonary diffusion, but not the degree of airway obstruction, independently predict CPET performance in elderly patients with COPD. In addition, peripheral muscle endurance, but not strength, also predicts CPET performance in these subjects.

Exercise assessments and trainings of pulmonary rehabilitation in COPD: a literature review

Skeletal muscle dysfunction leads to reduction in activity in patients with COPD. As an essential part of the management of COPD, pulmonary rehabilitation (PR) alleviates dyspnea and fatigue, improves exercise tolerance and health-related quality of life, and reduces hospital admissions and mortality for COPD patients. Exercise is the key component of PR, which is composed of exercise assessment and training therapy. To evaluate PR’s application in clinical practice, this article summarizes the common methods of exercise measurement and exercise training for patients with COPD. Exercise assessments should calculate patients’ symptoms, endurance, strength, and health-related quality of life. After calculation, detailed exercise therapies should be developed, which may involve endurance, strength, and respiratory training. The detailed exercise training of each modality is mentioned in this review. Although various methods and therapies of PR have been used in COPD patients, developing an individualized exercise training prescription is the target. More studies are warranted to support the evidence and examine the effects of long-term benefits of exercise training for patients with COPD in each stage.

Effectiveness of water-based Liuzijue exercise on respiratory muscle strength and peripheral skeletal muscle function in patients with COPD

Objects

The purpose of this study was to quantitatively assess the effects of water-based Liuzijue exercise on patients with COPD and compare it with land-based Liuzijue exercise.

Materials and methods

Participants were randomly allocated to one of three groups: the water-based Liuzijue exercise group (WG), the land-based Liuzijue exercise group (LG), and the control group (CG). CG participants accepted no exercise intervention, while training groups performed Liuzijue exercise according to Health Qigong Liuzijue (People's Republic of China) in different environments for 60-min sessions twice a week for 3 months.

Results

Of the 50 patients enrolled, 45 (90%) completed the 3-month intervention. The CG showed decreased expiratory muscle strength, extensor and flexor endurance ratio (ER) of the elbow joints and flexor peak torque (PT), total work (TW), and ER of the knee joints (p<0.05). Both training groups showed improved respiratory muscle strength, which differed from the CG (p<0.001). In addition, extensor and flexor TW of the elbow joints in the training groups were increased (p<0.01), and the WG differed from the CG in extensor TW and ER and flexor TW (p<0.01), while the LG differed from the CG in flexor TW and extensor ER (p<0.05). PT, PT/body weight (BW), and TW in the knee joint extensor in the training groups were increased as well (PT and PT/BW: p<0.05, TW: p<0.01), and the WG differed from the CG in terms of knee joints outcomes, while the LG differed from the CG in flexor TW only (p<0.05).

Conclusion

Water-based Liuzijue exercise has beneficial effects on COPD patients' respiratory muscle strength and peripheral skeletal muscle function, and additional benefits may exist in endurance of upper limbs and strength and endurance of lower limbs when compared with land-based Liuzijue exercise.

Personalized diet and exercise recommendations in early rheumatoid arthritis: A feasibility trial

BACKGROUND

Physical activity and diet have a positive influence on disease activity and cardiovascular risk in patients with rheumatoid arthritis (RA).

OBJECTIVE

We tested the feasibility and effect of a brief individualized counselling intervention on physical activity levels and fitness, and dietary intake, compared with standard of care.

METHODS

Thirty patients with inflammatory arthritis (<1 year duration) were assigned to standard of care or the intervention, which consisted of individualized visits with a dietetic intern and physiotherapist at two time points, to review age-specific strategies on diet and exercise. Primary outcomes included anthropometric measurements (height, weight, waist and hip circumference), nutritional intake, physical activity (pedometer steps) and physical fitness. Disease activity measures and biochemical testing (blood pressure measurement, inflammatory markers, cholesterol profile and random glucose) were collected. The changes in these outcomes from baseline to 6 months were assessed using paired t-tests between groups.

RESULTS

Thirteen patients in the intervention group and 10 in the control group completed the study. There were non-significant trends in improvements in physical activity, low-density lipoprotein cholesterol level and nutritional intake (vitamin C, iron, fibre, vitamin A and folate) in the intervention group.

CONCLUSIONS

Poor enrolment and high dropout rates in this short-term study highlighted the difficulty of behavioural change. Those continuing in the study and who received the intervention demonstrated a non-significantly improved activity level and nutritional intake that may benefit long-term outcomes.

Gait abnormalities of COPD are not directly related to respiratory function

STUDY OBJECTIVE

To assess whether gait abnormalities in COPD depend on mere impairment of respiratory function.

METHODS

In 40 patients with COPD at different GOLD stages and 28 controls, we evaluated: forced expiratory volume in 1s (FEV1); partial pressure of oxygen; Mini-Mental State Examination (MMSE); dynamic balance through the Mini-BESTest (MBT); Timed Up and Go (TUG) test without and with dual task counting aloud back by three; 6-min walk test (6MWT); body sway during quiet stance (stabilometry); spatial-temporal variables of gait by a 4-m long sensorized walkway (baropodometry). Lower-limb muscle strength, tendon reflexes, and sensation were also clinically evaluated.

RESULTS

Muscle strength of proximal but not distal muscles was slightly reduced in patients, whereas reflexes and sensation were unaffected. FEV1, partial pressure of oxygen, MMSE, MBT, stabilometry, as well as baropodometry, were abnormal and unrelated to muscle weakness. The time taken to perform the TUG test was increased, and to a larger extent with than without dual task. At baropodometry, variability of step length was increased; abnormalities of gait variables were associated with larger body sway but not with FEV1 or hypoxemia. Gait speed at 6MWT was correlated with MBT score and with FEV1 as well as hypoxemia.

CONCLUSIONS

6MWT findings give a measure of gait disability linked to endurance-related respiratory failure. Gait at baropodometry is associated with impairment of balance, cognitive status and abnormal dual task performance. We suggest that central nervous lesions, presumably of vascular origin, are detrimental to balance and gait in COPD.

Changes in lower limb muscle function and muscle mass following exercise-based interventions in patients with chronic obstructive pulmonary disease: A review of the English-language literature

Chronic obstructive pulmonary disease (COPD) patients often experience lower limb muscle dysfunction and wasting. Exercise-based training has potential to improve muscle function and mass, but literature on this topic is extensive and heterogeneous including numerous interventions and outcome measures. This review uses a detailed systematic approach to investigate the effect of this wide range of exercise-based interventions on muscle function and mass. PUBMED and PEDro databases were searched. In all, 70 studies (n = 2504 COPD patients) that implemented an exercise-based intervention and reported muscle strength, endurance, or mass in clinically stable COPD patients were critically appraised. Aerobic and/or resistance training, high-intensity interval training, electrical or magnetic muscle stimulation, whole-body vibration, and water-based training were investigated. Muscle strength increased in 78%, muscle endurance in 92%, and muscle mass in 88% of the cases where that specific outcome was measured. Despite large heterogeneity in exercise-based interventions and outcome measures used, most exercise-based trials showed improvements in muscle strength, endurance, and mass in COPD patients. Which intervention(s) is (are) best for which subgroup of patients remains currently unknown. Furthermore, this literature review identifies gaps in the current knowledge and generates recommendations for future research to enhance our knowledge on exercise-based interventions in COPD patients.

Validity and reliability of strain gauge measurement of volitional quadriceps force in patients with COPD

This study investigated the validity and reliability of fixed strain gauge measurements of isometric quadriceps force in patients with chronic obstructive pulmonary disease (COPD). A total cohort of 138 patients with COPD were assessed. To determine validity, maximal volitional quadriceps force was evaluated during isometric maximal voluntary contraction (MVC) manoeuvre via a fixed strain gauge dynamometer and compared to (a) potentiated non-volitional quadriceps force obtained via magnetic stimulation of the femoral nerve (twitch (Tw); n = 92) and (b) volitional computerized dynamometry (Biodex; n = 46) and analysed via correlation coefficients. Test-retest and absolute reliability were determined via calculations of intra-class correlation coefficients (ICCs), smallest real differences (SRDs) and standard errors of measurement (SEMs). For this, MVC recordings in each device were performed across two test sessions separated by a period of 7 days ( n = 46). Strain gauge measures of MVC demonstrated very large correlation with Tw and Biodex results ( r = 0.86 and 0.88, respectively, both p < 0.0001). ICC, SEM and SRD were numerically comparable between strain gauge and Biodex devices (ICC = 0.96 vs. 0.93; SEM = 8.50 vs. 10.54 N·m and SRD = 23.59 vs. 29.22 N·m, respectively). The results support that strain gauge measures of quadriceps force are valid and reliable in patients with COPD.

Microvascular oxygen extraction during maximal isometric contraction in patients with chronic obstructive pulmonary disease

Abstract Introduction: COPD presents decrease in oxidative metabolism with possible losses of cardiovascular adjustments, suggesting slow kinetics microvascular oxygen during intense exercise. Objective: To test the hypothesis that chronic obstructive pulmonary disease (COPD) patients have lower muscle performance in physical exercise not dependent on central factors, but also greater muscle oxygen extraction, regardless of muscle mass. Methods: Cross-sectional study with 11 COPD patients and nine healthy subjects, male, paired for age. Spirometry and body composition by DEXA were evaluated. Muscular performance was assessed by maximal voluntary isometric contraction (MVIC) in isokinetic dynamometer and muscle oxygen extraction by the NIRS technique. Student t-test and Pearson correlation were applied. A significance level of p<0.05 was adopted. Results: Patients had moderate to severe COPD (FEV1 = 44.5 ± 9.6% predicted; SpO2 = 94.6 ± 1.6%). Lean leg mass was 8.3 ± 0.9 vs. 8.9 ± 1.0 kg (p =0.033), when comparing COPD and control patients, respectively. The decreased muscle oxygen saturation corrected by muscle mass was 53.2% higher (p=0.044) in the COPD group in MVIC-1 and 149.6% higher (p=0.006) in the MVIC-2. Microvascular extraction rate of oxygen corrected by muscle mass and total work was found to be 114.5% higher (p=0.043) in the COPD group in MVIC-1 and 210.5% higher (p=0.015) in the MVIC-2. Conclusion: COPD patients have low muscle performance and high oxygen extraction per muscle mass unit and per unit of work. The high oxygen extraction suggests that quantitative and qualitative mechanisms can be determinants of muscle performance in patients with COPD.

Adaptations in limb muscle function following pulmonary rehabilitation in patients with COPD - a review

Even though chronic obstructive pulmonary disease (COPD) is primarily a disease of the respiratory system, limb muscle dysfunction characterized by muscle weakness, reduced muscle endurance and higher muscle fatigability, is a common secondary consequence and a major systemic manifestation of the disease. Muscle dysfunction is especially relevant in COPD because it is related to important clinical outcomes such as mortality, quality of life and exercise intolerance, independently of lung function impairment. Thus, improving muscle function is considered an important therapeutic goal in COPD management. Pulmonary rehabilitation (PR) is a multidisciplinary, evidence-based and comprehensive approach used to promote better self-management of the disease, minimize symptom burden, optimize functional status, and increase participation in activities of daily life. Exercise training, including cardiovascular and muscle exercises, is the cornerstone of PR and is considered the best available strategy to improve exercise tolerance and muscle function among patients with COPD. This paper addresses the various components of exercise training within PR used to improve limb muscle function in COPD, providing clinicians and health-care professionals with an overview and description of these various exercise modalities and of their effects on limb muscle function. Guidance and recommendations to help design optimal limb muscle training regimens for these patients are also presented.

Assessment and predictors of physical functioning post-hospital discharge in survivors of critical illness

Background

Prior studies of physical functioning after critical illness have been mostly limited to survivors of acute respiratory distress syndrome. The purpose of this study was to objectively assess muscle strength and physical functioning in survivors of critical illness from a general ICU and the associations of these measures to health-related quality of life (HRQL), mental health and critical illness variables.

Methods

This was a prospective cohort study of 56 patients admitted to a medical ICU (length of stay ≥4 days) from April 1, 2009, and March 31, 2010. Patients were assessed in clinic at 3 months post-hospital discharge. Muscle strength and physical functioning were measured using hand-held dynamometry and the 6-min walk test. HRQL was assessed using the short-form 36 (SF-36) and EuroQol-5D (EQ-5D) questionnaires.

Results

Three months post-hospital discharge, median age- and sex-matched muscle strength was reduced across all muscle groups. The median 6-min walk distance was 72 % of predicted. Physical functioning was associated with reductions in self-reported HRQL (SF-36, EQ-5D) and increased anxiety. Univariate regression modeling showed that reduced muscle strength and 6-min walk distance were associated with sepsis but not ICU length of stay. Multivariate regression modeling showed that sepsis and corticosteroid use were associated with a reduced 6-min walk distance, but again ICU length of stay was not.

Conclusions

Survivors of critical illness have reduced strength in multiple muscle groups and impaired exercise tolerance impacting both HRQL and mental health. These outcomes were worsened by sepsis and corticosteroid use in the ICU but not ICU length of stay. Interventions to minimizing the burden of sepsis in critically ill patients may improve long-term outcomes.