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Impact of estrogen deficiency on diaphragm and leg muscle contractile function in female mdx mice.

Female carriers of Duchenne muscular dystrophy (DMD) presenting with DMD symptomology similar to males with DMD, such as skeletal muscle weakness and cardiomyopathy, are termed manifesting carriers. There is phenotypic variability among manifesting carriers including the age of onset, which can range from the first to fourth decade of life. In females, estrogen levels typically begin to decline during the fourth decade of life and estrogen deficiency contributes to loss of muscle strength and recovery of strength following injury. Thus, we questioned whether the decline of estrogen impacts the

Motor control performance-related modulation of beta-band EEG-sEMG coherence differs between general and local muscular exercise-induced fatigue.

PURPOSE: Exercise-induced fatigue can reduce motor control performance and increase the risk of sporting injuries, which are related to functional coupling within the corticomotoneuronal pathway. However, the differences in functional coupling caused by general and local muscular exercise-induced fatigue are unknown. This study aimed to investigate the effects of exercise-induced fatigue on the beta-band (16-30 Hz) functional coupling between the sensorimotor cortex (SM1) and muscles of the dominant lower limb under different fatigue protocols. METHODS: Twenty-four healthy male participants w

[Sleep disorders and fatigue in patients with different forms of myotonic dystrophy type 1].

OBJECTIVE: To characterize sleep disorders in children and adults with different forms of myotonic dystrophy type 1 (DM1), to assess their impact on cognitive functions, excessive daytime sleepiness (EDS) and fatigue, to determine the relationship of EDS, fatigue, and sleep disorders with the quality of life of patients. MATERIAL AND METHODS: The study included 48 adults and 9 children with confirmed DM1. Patients underwent an assessment of clinical and anamnestic data, neurological, cognitive status, severity of EDS, fatigue, quality of life according to international scales and questionnair

Functional consequences of acute and chronic hypoxia on respiratory and skeletal muscles in mammals.

Reduced oxygen supply to contracting muscles affects not only the metabolic paths but also modifies the gain of sensorimotor reflex loops initiated from the activation of specialized nervous endings that detect the changes in muscle metabolism and membrane outflow of potassium. Large differences are found between skeletal muscles and the diaphragm with respect to their sensitivity to acute or chronic hypoxia. The diaphragm tolerates much more hypoxemia than do skeletal muscles, namely those constituted by a large proportion of slow twitch oxidative fibers. Acute hypoxemia or ischemia accentuat

Heat shock does not attenuate low-frequency fatigue.

Whole-body hyperthermia or heat shock confers protection to myocardial contractility against reperfusion-induced injury. The purpose of this study was to determine whether heat shock could provide similar protection to skeletal muscle contractility against low-frequency fatigue. Male Sprague-Dawley rats (6 rats/group) were heat shocked at 41.5 degrees C for 15 min either 24 h or 4 days prior to fatiguing stimulation to compare the contractile responses of the plantaris muscle with those of a nonheated group. Both 24 h and 4 days after heat shock, the 72-kDa heat shock protein (HSP72) was eleva

The role of potassium in muscle membrane dysfunction in end-stage renal disease.

OBJECTIVE: Uremic myopathy is a condition seen in end-stage renal disease (ESRD), characterized by muscle weakness and muscle fatigue, in which the pathophysiology is uncertain. The aim of this study was to assess the role of abnormal serum constituents in ESRD patients by relating them to the excitability properties of the tibialis anterior muscle, at rest and during electrically induced muscle activation, by recording muscle velocity recovery cycles (MVRC) and frequency ramp responses. METHODS: Eighteen ESRD patients undergoing hemodialysis were evaluated by blood sample, MVRC, and frequenc…

Alterations in pitching biomechanics and performance with an increasing number of pitches in baseball pitchers: A narrative review.

In baseball pitchers, the association of fatigue with overuse injury and decline in pitching performance has been discussed frequently, but the scientific data concerning their interrelationships have been inconsistently reported. The purpose of this narrative review is to summarize and explore the evidence regarding acute changes in pitching biomechanics and performance from repetitive throwing motions among baseball pitchers. Muscle fatigue from repetitive throwing not only decreases muscle output but also disturbs the kinetic chain of baseball pitching. In addition, repetitive throwing can …

Exercise training in adults with Pompe disease: the effects on pain, fatigue, and functioning.

OBJECTIVE: To assess if a 12-week exercise intervention to improve aerobic fitness, muscle strength, and core stability also had an impact on fatigue, pain, activity, and participation in adults with Pompe disease, an inherited neuromuscular disorder. DESIGN: Open-label trial. Change was assessed by the chi-square test and Wilcoxon signed-rank test. SETTING: Physiotherapy practices. PARTICIPANTS: Mildly affected adult patients with Pompe disease who were not dependent on ventilators and/or walking devices and were receiving enzyme replacement therapy. INTERVENTION: Patients participated in

Effects of theophylline on pharyngeal dilator and diaphragm muscle contractile properties.

Theophylline alleviates central and obstructive apneas of prematurity, and may improve adult obstructive sleep apnea. One mechanism of action appears to be a stimulatory effect on the motor output to upper airway dilator muscles. The purpose of the present study was to determine whether theophylline might have a second mechanism of action, namely that of improving the force and/or endurance of the pharyngeal dilator musculature. Rat sternohyoid muscle strips were studied in vitro and compared to diaphragm strips. The isometric twitch force and twitch kinetics of neither muscle were altered by

Multipoint surface electromyography measurement using bull's-eye electrodes for wide-area topographic analysis.

BACKGROUND: Surface electromyography (sEMG) is primarily used to analyze individual and neighboring muscle activity. However, using a broade … multipoint sEMG measurements using a bull's-eye electrode setup. This system effectively evaluates muscle fatigue and provides a comprehensive topographic view of muscle activity. These results mark a significant step towards developing a future multichannel sEMG system with enhanced measurement points and improved wearability. TRIAL REGISTRATION: This study w …

Effects of Different Gum Hardness on Masseter Muscle Activity During Gum Chewing: An NIRS Oximetry Study.

Gum chewing is used in orofacial therapy to improve oral functions, such as a patient's chewing ability, bite force, tongue pressure, and li … were observed in masseter muscle tissue oxygen dynamics. Likewise, muscle activity, heart rate, and muscle fatigue (according to VAS) also increased significantly as gum hardness increased. The findings of this study reveal that increasing gum base hardness not only affects masseter muscle tissue oxygen dynamics but also increases muscle activity, masseter fatig …

Running improves muscle mass by activating autophagic flux and inhibiting ubiquitination degradation in mdx mice.

BACKGROUND: Exercise therapy can improve muscle mass, strengthen muscle and cardiorespiratory function, and may be an excellent adjunctive treatment option for Duchenne muscular dystrophy. METHODS: This article investigates the effects of 10 weeks of treadmill training on skeletal muscle in control and mdx mice. Hematoxylin and eosin (H&E) staining was used to detect the morphometry of skeletal muscle; the grip strength test, suspension test, and rotarod test were used to detect limb muscle strength of mice, and Aurora Scientific Instruments were used to detect in vivo Muscle Stimulation Meas

[Effectiveness of Resistance Training on Multiple Sclerosis-Related Fatigue: A Systematic Review].

BACKGROUND: Patients with multiple sclerosis (MS) often experience impaired muscular fitness and fatigue. Exercise is known to help maintain muscle fitness and alleviate fatigue, with resistance training being recommended as a potential intervention. However, due to the variety of resistance exercises used and inconsistencies in the results obtained, an evidence-based systematic review is needed to synthesize the effectiveness of this intervention. PURPOSE: This study was designed to synthesize the current research on the effectiveness of resistance training in improving muscle fitness and re

Нейромускульная функция у переживших полиомиелит.

Несмотря на отсутствие документально подтвержденных объективных доказательств того, что симптомы постполиологического заболевания быстро теряют свою силу, у них есть ряд нервно-мышечных недостатков, связанных с более серьезным полиомиелитом, что может объяснить, почему они жалуются на проблемы с силой, выносливостью и усталостью местных мышц. В период острого полиомиелита лица, страдающие симптомами постполиотического заболевания, госпитализировались дольше, восстанавливались медленнее и имели электромиографические данные, свидетельствующие о более значительной потере клеток переднего рога. Кр

Совпадение в аннотации оригинала
Although there is no documented, objective evidence that symptomatic post-polio subjects are rapidly losing strength, they have a number of neuromuscular deficits related to a more severe poliomyelitis illness that may explain why they complain of problems with strength, endurance, and local muscle fatigue. Symptomatic post-polio subjects were hospitalized l…

Effect of theophylline on diaphragmatic muscle function.

Recent investigations have shown that theophylline improves diaphragmatic contractility of the respiratory muscles in isolated muscle preparations in animals and in normal human subjects. It has also been demonstrated that theophylline can reverse diaphragmatic fatigue and prevent fatigue of the diaphragm when given prophylactically. These effects have also been demonstrated in patients with severe chronic obstructive pulmonary disease, all of whom retained CO2 (PaCO2 53 +/- 3 mm Hg) and had hypoxia (PaO2 57 +/- 8 mm Hg). Theophylline, which increases respiratory muscle strength and delays the

Influence of Fatigue on the Rapid Hamstring/Quadriceps Force Capacity in Soccer Players.

The objective of this study was to examine the effect of fatigue on maximal and rapid force capacities and muscular activation of the knee extensors and flexors. Seventeen professional soccer players volunteered to participate in this study. Peak torque (Tpeak) and rate of torque development (RTD) of knee flexor (90°. s-1, -30°. s-1) and extensor (90°. s-1) muscles were measured before and after fatigue (i.e., 30 maximal knee extension and flexion repetitions at 180°s-1) performed on an isokinetic dynamometer. Hamstring to quadriceps peak strength and RTD ratios were calculated. Besides, using

Inspiratory muscle dysfunction in patients with severe obstructive sleep apnoea.

Repetitive inspiratory effort against an obstructed airway and intermittent hypoxia may be deleterious to the inspiratory muscles in patients with obstructive sleep apnoea (OSA). We investigated muscular dysfunction by comparing the strength, endurance and fatigability of inspiratory muscles and knee extensors in patients with newly diagnosed severe OSA compared with matched controls. The measurements included strength and endurance tests of both muscles, and a fatigue trial with simultaneous surface electromyography of the diaphragm and the vastus lateralis during voluntary contractions and i

The Effect of Fatigue on Trunk and Pelvic Jump-Landing Biomechanics in View of Lower Extremity Loading: A Systematic Review.

Fatigue has often been considered a risk factor for developing sports injuries, modulating lower extremity jump-landing biomechanics. The im … ailing evidence for more trunk flexion during standardized jump-landing tasks after lower extremity muscle fatigue. Otherwise, lumbo-pelvic-hip muscle fatigue does not seem to elicit major detrimental changes to these jump-landing biomechanics. Although a wide variability of trunk and pelvic jump-landing strategies was observed, the results provide evidence for …

The effect of lower extremity fatigue on shock attenuation during single-leg landing.

BACKGROUND: The forces that are imposed on the body due to landings must be attenuated primarily in the lower extremity. Muscles assist in the absorption of these forces, and it has been shown that a fatigued muscle decreases the body's ability to attenuate shock from running. The purpose of the study was to determine the effect of lower extremity fatigue on shock attenuation and joint mechanics during a single-leg drop landing. METHODS: Ten active male participants were recruited (eight used for analysis). Each participant took part in a fatigue landing protocol. This protocol included cycle

Extracellular Water Excess and Increased Self-Reported Fatigue in Chronic Hemodialysis Patients.

Hemodialysis patients (HD) commonly report fatigue. Muscle wasting (sarcopenia) and extracellular water (ECW) excess have been reported to be associated with fatigue in other conditions. We wished to determine whether muscle loss and ECW excess were associated with fatigue in HD patients. Patients completed the Multidimensional Fatigue Inventory (MFI), Beck Depression Inventory-II (BDI-II), Patient Health Questionnaires (PHQ-9) and recorded their post-dialysis recovery time. Sessional dialysis data were recorded along with pre- and post-dialysis multi-frequency bioimpedance assessments (MFBIA)