Heliox Delays Exercise Dynamic Hyperinflation and Leg Muscle Fatigue in Ventilatory Limited Patients with COPD

Background: Contractile fatigue of the quadriceps occurs in a significant proportion of patients with COPD after constant-load cycling exercise. Dynamic hyperinflation, by altering cardiac output during exercise, could contribute to fatigue susceptibility in this population. The purpose of this study was to compare operational lung volumes during constant workrate exercise between COPD patients who do and those who do not develop contractile fatigue of the quadriceps (fatiguers vs non-fatiguers). Methods: Sixty-two patients with COPD (FEV1: 46±16%) completed a constant-load cycling test at 80% of the peak workrate achieved during progressive cycle ergometry. Ventilatory parameters were monitored breath-by-breath, while inspiratory capacity maneuvers were obtained every other minute during constant-load cycling. Quadriceps twitch force was measured with magnetic stimulation of the femoral nerve before and after the test. Muscle fatigue was defined as a post-exercise reduction in quadriceps twitch force of more than 15% of the resting value. Results: Forty patients (65%) developed muscle fatigue after constant-load cycling. No significant differences were found between fatiguers and non-fatiguers with respect to age, body mass index, resting lung function, peak oxygen consumption, and endurance time to constant-load exercise. Change in inspiratory capacity from rest to end-exercise (DIC) was similar between both subgroups (DIC: 0.56±0.32L vs 0.56±0.47L for fatiguers and non-fatiguers respectively, P=0.99). Conclusion: Susceptibility to muscle fatigue could not be predicted by exercise duration or by the degree of dynamic hyperinflation in patients with COPD.

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Effects of unilateral leg muscle fatigue on balance control in perturbed and unperturbed gait in healthy elderly

Gait & Posture ◽

10.1016/j.gaitpost.2014.03.194 ◽

2014 ◽

Vol 40 (1) ◽

pp. 215-219 ◽

Cited By ~ 16

Author(s):

Marcel J.P. Toebes ◽

Marco J.M. Hoozemans ◽

Joost Dekker ◽

Jaap H. van Dieën

Keyword(s):

Muscle Fatigue ◽

Balance Control ◽

Healthy Elderly ◽

Leg Muscle

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Effects of leg muscle fatigue on gait in patients with Parkinson's disease and controls with high and low levels of daily physical activity

Gait & Posture ◽

10.1016/j.gaitpost.2016.04.002 ◽

2016 ◽

Vol 47 ◽

pp. 86-91 ◽

Cited By ~ 16

Author(s):

Paulo Cezar Rocha Santos ◽

Lilian Teresa Bucken Gobbi ◽

Diego Orcioli-Silva ◽

Lucas Simieli ◽

Jaap H. van Dieën ◽

...

Keyword(s):

Physical Activity ◽

Parkinson’S Disease ◽

Parkinson's Disease ◽

Muscle Fatigue ◽

Daily Physical Activity ◽

Leg Muscle ◽

Low Levels

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Analysis of leg muscle fatigue using electromyography—Insights into chair ergonomics

Journal of Biomechanics ◽

10.1016/s0021-9290(06)83580-3 ◽

2006 ◽

Vol 39 ◽

pp. S167

Author(s):

S.K.M. Varadhan ◽

B. Venkatesh

Keyword(s):

Muscle Fatigue ◽

Leg Muscle

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Comparison of Physiological Effects Induced by Two Compression Stockings and Regular Socks During Prolonged Standing Work

Human Factors The Journal of the Human Factors and Ergonomics Society ◽

10.1177/00187208211022126 ◽

2021 ◽

pp. 001872082110221

Author(s):

Maria-Gabriela Garcia ◽

Maria Gloria Roman ◽

Andrea Davila ◽

Bernard J. Martin

Keyword(s):

Muscle Fatigue ◽

Lower Leg ◽

Healthy Individuals ◽

Compression Stockings ◽

Muscle Twitch ◽

Prolonged Standing ◽

Quantitative Evidence ◽

Before And After ◽

Leg Muscle ◽

Force Volume

Objective The goal of this study was to evaluate and compare lower-leg muscle fatigue, edema, and discomfort induced by the prolonged standing of security guards wearing regular socks and those wearing 15–20 or 20–30 mmHg compression stockings as intervention. Background Compression stockings are somewhat used by individuals standing all day at work. However, quantitative evidence showing their potential benefits for lower-leg health issues in healthy individuals during real working conditions is lacking. Method Forty male security employees participated in the study. All were randomly assigned to the control or one of the two intervention groups (I15–20 or I20–30). Lower-leg muscle twitch force, volume, and discomfort ratings were measured before and after their regular 12-hr standing work shift. Results Significant evidence of lower-leg long-lasting muscle fatigue, edema, and discomfort was observed after standing work for guards wearing regular socks. However, no significant changes were found for guards wearing either compression stockings. Conclusion In healthy individuals, compression stockings seem to attenuate efficiently the tested outcomes in the lower leg resulting from prolonged standing. Application Occupational activities requiring prolonged standing may benefit from 15–20 or 20–30 mmHg compression stockings. As similar benefits were observed for both levels of compression, the lower level may be sufficient.

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Being physically active minimizes the effects of leg muscle fatigue on obstacle negotiation in people with Parkinson’s disease

Journal of Biomechanics ◽

10.1016/j.jbiomech.2021.110568 ◽

2021 ◽

pp. 110568

Author(s):

Paulo Cezar Rocha dos Santos ◽

Fabio Augusto Barbieri ◽

Diego Orcioli-Silva ◽

Victor Spiandor Beretta ◽

Tibor Hortobágyi ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Muscle Fatigue ◽

Physically Active ◽

Leg Muscle

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Modulation of ventilatory mechanics during exercise in ventilation-limited populations

Applied Physiology Nutrition and Metabolism ◽

10.1139/h08-006 ◽

2008 ◽

Vol 33 (3) ◽

pp. 536-537 ◽

Cited By ~ 1

Author(s):

Scott J. Butcher

Keyword(s):

Pulmonary Function ◽

Muscle Fatigue ◽

Lung Volume ◽

Exercise Tolerance ◽

Healthy Subjects ◽

Respiratory Muscle ◽

Respiratory Muscle Fatigue ◽

The Third ◽

Leg Muscle ◽

The Impact

The aim of this thesis was to examine the impact of modifications to ventilatory constraint in populations who have reductions in expiratory flow and ventilatory limitations during exercise. The first study examined the effect of the self-contained breathing apparatus (SCBA) regulator on work of breathing (WOB) and lung volume changes in healthy subjects. The second study further examined the effect of the SCBA on the above outcomes, as well as on pulmonary function and respiratory muscle fatigue during stair-stepping (in healthy subjects). In addition, the effect of breathing heliox on the aforementioned variables was studied. The third thesis study examined the effect of heliox on ventilatory constraint, exercise tolerance, and leg muscle fatigue in patients with chronic obstructive pulmonary disease (COPD). The main results of the first study were that, compared with a low-resistance breathing valve (RV), the SCBA regulator increased inspiratory elastic (32%), expiratory resistive (59%), and total WOB (13%), and increased end-expiratory lung volume creating a plateau in end-inspiratory lung volume at approximately 90% of vital capacity. When these variables were examined with the full SCBA and compared with the RV in the second study, similar results were found. In addition, resting pulmonary function was reduced with the SCBA. Exercise with the SCBA induced reductions in both inspiratory and expiratory maximal pressures indicating the presence of respiratory muscle fatigue. When compressed air was replaced with heliox in the SCBA, end-expiratory lung volume, total WOB, and respiratory muscle fatigue were reduced. These observations regarding the effect of heliox on ventilatory function led to the third study, which found that heliox increased exercise tolerance (53%) and leg muscle fatigue (15%) in patients with COPD, but only in those limited by ventilatory constraints and who did not have a significant level of leg fatigue while breathing room air. Those patients who did have leg fatigue on room air did not increase exercise tolerance despite reduced ventilatory constraint. Together, these findings indicate that reducing ventilatory constraint during exercise can have specific positive effects on exercise performance in populations who are ventilatory limited and have implications for occupational or rehabilitation exercise training.

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