Quadriceps frequency skeletal muscle contractions. Medical search. Frequent questions

The quadriceps femoris muscle was stimulated with constant frequency trains (CFTs) (six 200 s square wave pulses separated by 70 ms) or VFTs (a train identical to the CFT, except that the first two pulses were separated by 5 ms) in SCI and AB subjects. (gsu.edu)
EMG frequency content changes with increasing force and during fatigue in the quadriceps femoris muscle of men and women. (sciepub.com)

NMES and Skeletal Muscle Fatigue" by Monica A. Mendoza, Kyndall P. Ramirez et al. (wku.edu)
However, little is known regarding the effects of a high-frequency NMES intervention on voluntary skeletal muscle fatigue. (wku.edu)
The aim of this study was to determine the effect of a 4-week high-frequency NMES intervention on voluntary muscular fatigue and changes in neuromuscular activation patterns of the quadriceps during voluntary fatiguing muscle contractions in older adults. (wku.edu)
All subjects performed maximal voluntary contractions (MVC) and an intermittent knee extension isometric submaximal voluntary fatigue task at 50% MVC until the fatigue criteria were met for pre-post testing. (wku.edu)
Surface electromyography (sEMG) of the vastus lateralis (VL) and vastus medialis (VM) muscles were recorded during the fatigue task to examine changes in muscle activation. (wku.edu)
EMG data were quantified for root mean square (RMS) EMG and reported as a percent rate of change over the duration of the fatigue task and median frequency (MF) is reported as the average MF during the fatigue task. (wku.edu)
Skeletal muscle, after spinal cord injury (SCI), becomes highly susceptible to fatigue. (gsu.edu)
We discuss implications of our model approach for enhancing muscle models in general, as well as a few aspects regarding the significance of phosphate kinetics as one contributor to muscle fatigue. (frontiersin.org)
One of the first books addressing (muscle as well as whole body) fatigue was published at the beginning of the 20th century ( Mosso, 1904 ) and a multitude of research has followed since, see Gandevia (2001) for a thorough review. (frontiersin.org)
Commonly, muscle fatigue, i.e., the decline of the generable force level over time, is differentiated between central fatigue , i.e., the inability of the neural network to provide sufficient stimulation, and peripheral fatigue , i.e., the inability of the muscle cells to provide energy through metabolic activities (cf. (frontiersin.org)
Human skeletal muscle responses vary with age and gender during fatigue due to incremental isometric exercise. (sciepub.com)
Muscular fatigue causes a slowing of muscle contraction velocity, reversing as the muscle recovers from fatigue [ 21 - 24 ]. (plos.org)
This is most likely due to higher levels of fatigue occurring in less trained muscles. (theconversation.com)
The central drive to the muscle reduces when muscle force wanes during sustained MVC, and this is generally considered the neurophysiological footprint of central fatigue. (nature.com)
The question is if force loss and the failure of central drive to the muscle are responsible mechanisms of fatigue induced by un-resisted repetitive movements. (nature.com)
Our data suggest that force and central drive to the muscle are not determinants of fatigue induced by short-lasting un-resisted repetitive finger movements, even in the presence of increased inhibition of the motor cortex. (nature.com)
Muscle fatigue induced by sustained contractions may develop at the muscle but also at neural levels (i.e., central fatigue) 1 . (nature.com)
The twitch-interpolation technique evaluates central fatigue by assessing the level of central drive to the muscle (also called voluntary activation, VA). It involves a first percutaneous electric stimulation (PNS) of a nerve (or muscle motor point) during a maximal voluntary contraction (MVC), which normally increases the ongoing force-torque developed by the muscle (interpolated twitch). (nature.com)
The question to be answered is if the failure of central drive to the muscle is a responsible mechanism of fatigue induced by different activities than those involving isometric contractions. (nature.com)
In addition to central fatigue, fatigue at peripheral level also reduces muscle performance. (nature.com)
Furthermore, evoked spinal reflex responses of the soleus muscle (H-reflex evoked at rest and during iMVC, V-wave), peak twitch torques induced by electrical stimulation of the posterior tibial nerve at rest and fatigue resistance were evaluated. (frontiersin.org)
The 30-second all-out sprint cycling exercise is a classical sport capacity evaluation method, which may cause severe lower limb muscle fatigue. (hindawi.com)
However, the relationship between lower limb muscle fatigue and the decline in exercise performance during 30-second sprint cycling remains unclear. (hindawi.com)
Of the muscles evaluated, the degree of fatigue of TA showed the greatest association with exercise performance decline, whereas the muscle fatigue of RF, VAS, and GAS also significantly impacted exercise performance during a 30-second all-out sprint cycling exercise. (hindawi.com)
As a vigorous exercise, 30-second all-out cycling causes severe lower limb muscle fatigue, which manifests as a decline in exercise performance [ 2 , 3 ]. (hindawi.com)
In fact, muscle fatigue occurs as early as five seconds in this intensive exercise [ 1 , 4 ]. (hindawi.com)
As the decline in exercise performance during 30-second sprint cycling is mainly determined by the fatigue of lower limb muscles, investigating the relationship between lower limb muscle fatigue and changes in exercise performance may further help in understanding the movement and aid training programme design. (hindawi.com)
Previous research evaluating muscle fatigue has mainly focused on total muscle fatigue at the end of the exercise or fatigue development in only a few muscles [ 2 , 4 ]. (hindawi.com)
Furthermore, earlier studies did not simultaneously quantify the development and progression of muscle fatigue in multiple lower limb muscles during 30-second sprint cycling. (hindawi.com)
As different muscles have different functional roles during pedalling exercise, the process of fatigue development of each lower limb muscle can differ significantly [ 3 , 5 ]. (hindawi.com)
For example, muscle activity of the quadriceps decreased by approximately 8% during 30-second sprint cycling, whereas that of the gastrocnemius (GAS) decreased by up to 15%, indicating an unbalanced development of fatigue for the two muscle groups [ 5 - 7 ]. (hindawi.com)
Thus, the relationship between the fatigue development of each lower limb muscle and changes in exercise performance during 30-second sprint cycling remains unclear. (hindawi.com)
Previous research has commonly evaluated local muscle fatigue using surface electromyography (EMG) signal processing. (hindawi.com)
Among comparisons of the utility of different methods to evaluate muscle fatigue, the wavelet transform has better accuracy and precision than those obtained from other time-frequency analysis methods in processing nonstationary EMG signals recorded during dynamic contractions [ 11 ]. (hindawi.com)
Based on this finding, MNF exhibits superior utility to other indices in muscle fatigue evaluation induced by sprint cycling exercise, suggesting that the fatigue of lower limb muscles during a 30-second all-out cycling exercise can be assessed well using the MNF of EMG signals. (hindawi.com)
Achten, E. β-alanine supplementation augments muscle carnosine content and attenuates fatigue during repeated isokinetic contraction bouts in trained sprinters. (rbpfex.com.br)
The lack of coordination between muscles can also cause fatigue and pain. (kif1a.org)
Muscle glycogen content is important for high-intensity exercise, and low levels are related to fatigue [ 1 ]. (biomedcentral.com)
Muscular fatigue affects the muscle activation that is needed for producing the desired clinical outcome. (waset.org)
The FDB is made up of small predominantly type IIa and IIx fibers that collectively produce less peak isometric force than the extensor digitorum longus (EDL) or soleus muscles, but demonstrates a greater fatigue resistance than the EDL. (biomedcentral.com)
Although the exact cause of the cramping isn't known, researchers do believe that they can be caused by inadequate stretching, muscle fatigue, or lack of oxygen to the muscle. (concordortho.com)

Variable-frequency trains (VFTs) enhance force in fatigued human skeletal muscle of able-bodied (AB) individuals. (gsu.edu)
Söderlund, K. and Hultman, E. ATP content in single fibres from human skeletal muscle after electrical stimulation and during recovery. (biothema.com)

Neuromuscular electrical stimulation (NMES) is often used as a rehabilitative modality and evidence has suggested that high frequencies of NMES may elicit increases in muscle strength. (wku.edu)
Söderlund, K. and Hultman, E. ATP and phosphocreatine changes in single human muscle fibers after intense electrical stimulation. (biothema.com)
Söderlund, K., Greenhaff, P.L., and Hultman, E. Energy metabolism in type I and type II human muscle fibres during short term electrical stimulation at different frequencies. (biothema.com)
A muscle twitch is the contractile response to a single electrochemical signal of the nervous system or artificial electrical stimulation of the muscle. (plos.org)
Background: Passive training of specific locomotor muscle groups by means of neuromuscular electrical stimulation (NMES) might be better tolerated than whole body exercise in patients with severe chronic obstructive pulmonary disease (COPD). (bmj.com)
Conclusions: For severely disabled COPD patients with incapacitating dyspnoea, short term electrical stimulation of selected lower limb muscles involved in ambulation can improve muscle strength and endurance, whole body exercise tolerance, and breathlessness during activities of daily living. (bmj.com)
We therefore propose that passive stimulation of locomotor muscle groups by neuromuscular electrical stimulation (NMES) may provide an alternative approach for improving physical capacity in severely compromised patients with COPD who present with incapacitating dyspnoea. (bmj.com)
These evoked potentials are elicited by electrical stimulation of the posterior tibial nerve in the popliteal fossa and their amplitudes can be recorded in the soleus muscle (SOL). (frontiersin.org)
EMS is an interesting training tool for athletes, because during electrical stimulation the 'fast-twitch' muscle fibres can be activated more easily at lower force levels, whereas during voluntary exercise these fibres are usually recruited for higher power levels. (compex.com)
The authors conclude there is compelling evidence that electrical stimulation is a relevant and efficient complement to voluntary resistance training protocols for muscle strength improvement, with knee extensor maximum voluntary contraction increasing by up to 27% and muscle volume increasing by 8% after 8 weeks. (compex.com)

Maximal voluntary isometric contraction and evoked torque, muscle architecture, sensory discomfort (visual analog scale), and electromyographic activity were evaluated before and after the 6-week period. (humankinetics.com)
The purpose of this study was to determine the effect of strength ramp isometric contraction on changes in surface electromyography (sEMG) signal characteristics of the hamstrings muscles. (waset.org)

Subjects first performed a maximal isometric knee extension (IKE) and knee flexion (IKF) followed by the IS and muscle activity (EMG max ) was recorded for the vastus medialis (VMO), vastus lateralis (VL), semitendinosus (ST) and biceps femoris (BF). (jssm.org)
The agonist-antagonist muscles considered for the study were Rectus femoris (Quadriceps Muscle group), Biceps femoris (Hamstring Muscle group), Tibialis Anterior and Soleus. (sciepub.com)
In this study, four muscle relaxation periods (30, 60, 90 and 120 seconds) and their effectiveness in producing consistent muscle activation of the muscle biceps brachii between sets of an elbow flexion and extension task were investigated among a sample of 10 subjects with no disabilities. (waset.org)
On average, the muscle activity of the biceps brachii decreased by 0.3% when rested for 30 seconds, and it increased by 1.25%, 0.76% and 0.82% when using muscle relaxation periods of 60, 90 and 120 seconds, respectively. (waset.org)
Lower limb muscles commonly affected the adductors, psoas, and quadriceps while the deltoid, triceps, and biceps are most commonly affected in the upper limbs. (symptoma.com)
Most cases of LGMD present with mainly proximal weakness affecting the biceps, neck muscles, and facial muscles. (symptoma.com)

The primary purpose of this investigation was to determine whether strength-matched men and women exhibit a different magnitude and ratio of leg muscle activity during a maximal voluntary isometric squat. (jssm.org)
This investigation indicates that the magnitude of muscle activity and the ratios examined are not significantly different between men and women in a maximal voluntary isometric squat when matched for normalized strength. (jssm.org)

Pieces of bone can be left at the proximal and/or distal end of skeletal muscles to allow for anchoring. (wikipedia.org)
When the muscle is strained the initial injury is usually associated with disruption of the distal myotendinous junction and fibres distal to this but still near the myotendinous junction. (musculoskeletalkey.com)
Generally, presentation varies with the type of LGMD involved, however, typical features include proximal muscle weakness (distal involvement in some cases), leading to difficulty ambulating , waddling gait , and hypotonia . (symptoma.com)
Distal muscle strength is almost always preserved. (symptoma.com)
In addition to proximal muscle weakness , there may or may not be: Distal muscle weakness . (symptoma.com)

In vitro muscle testing has provided the bulk of scientific knowledge of muscle structure and physiology, and how both relate to organismal performance. (wikipedia.org)

In vitro muscle testing can be done on any scale of muscle organization - entire groups of muscles (provided they share a common insertion or origin, as in the human quadriceps), a single muscle, a "bundle" of muscle fibers, a single muscle fiber, a single myofibril, a single sarcomere, a cardiomyocyte or even a half-sarcomere. (wikipedia.org)
Initiated by neural impulses and subsequent calcium release, skeletal muscle fibers contract (actively generate force) as a result of repetitive power strokes of acto-myosin cross-bridges. (frontiersin.org)
In this order, strength training with eccentric loading generates great tensions in the musculature, establishing neural adaptations, given by eccentric exercise, due to the fact that they improve the nerve impulse response from the spinal cord, as well as the development of a better synchronization of muscle fiber activation and an increase in the recruitment of fast-acting type II fibers (McHugh, 2003) . (sld.cu)
the bigger, more frequently used muscles have more fibers than the smaller, lesser used ones. (concordortho.com)
When the contraction/relaxation cycles are done repeatedly, as in exercising, the fibers become stronger and the muscles get larger and stronger. (concordortho.com)
However, sometimes the muscles, or just a few fibers within the muscle, contract on their own, causing a muscle spasm or cramp . (concordortho.com)
When researchers tested the cramping muscles of some athletes, they found rapid repetitive muscle firing , which could be described as the muscle fibers being hyperactive, in a sense. (concordortho.com)

However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC) and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals without the endurance training stimulus. (frontiersin.org)
During neuromuscular testing, rate of torque development, isometric maximum voluntary torque and muscle activation were measured. (frontiersin.org)

In this study, ten cyclists volunteered to participate in a 30-second all-out sprint cycling while power, cadence, and surface electromyographic (EMG) signals of eight lower limb muscles were recorded during the exercise. (hindawi.com)
The 30-second all-out sprint cycling exercise is a commonly used method in evaluating the anaerobic endurance capacity of lower limb muscles and has been widely adopted in sports training for cyclists [ 1 ]. (hindawi.com)

Therefore, a shorter Tc is commonly associated with a higher contraction velocity [ 8 - 11 ]. (plos.org)
Strains most commonly occur in muscles working across two joints e.g. hamstrings, gastrocnemius (Jarvinen et al. (musculoskeletalkey.com)
First, we characterized the FDB phenotype and provide reference comparisons to skeletal muscles commonly used in the field. (biomedcentral.com)
Using a novel approach, we also demonstrate methods for assessing mitochondrial respiration in the FDB, which are comparable to the commonly used gastrocnemius muscle. (biomedcentral.com)
Muscles commonly used for functional and mechanistic experiments include the extensor digitorum longus (EDL), soleus, plantaris, gastrocnemius, tibialis anterior (TA), and/or the quadriceps. (biomedcentral.com)
When it comes to muscle cramps, the most commonly affected muscles are the muscles of your upper arms, the muscles behind your thighs, and the muscles in the front of your thighs. (concordortho.com)

The purpose of this study was to investigate the influence of gender on the activity of agonist-antagonist muscles during maximum knee and ankle contraction in males (n1=10) and females (n2=10) adult population. (sciepub.com)
Different movements of knee and ankle used for the maximum contractions were knee flexion and extension, ankle plantar flexion and dorsiflexion. (sciepub.com)
Active agonist-antagonist muscle pairs during knee and ankle contractions were found to have minimum mechanical energy expenditure. (sciepub.com)
Changes in the strength of gastrocnemius, the ankle range of motion, and the muscle cross-section area of the lower leg were evaluated before and after the intervention. (biomedcentral.com)
The gastrocnemius muscle strength, ankle joint range of motion, and cross-sectional muscle area of the lower leg in the three groups showed a downward trend, indicating that the overall trend of muscle atrophy in ICU patients was irreversible. (biomedcentral.com)

OSD is a traction phenomenon resulting from repetitive quadriceps contraction through the patellar tendon at its insertion upon the skeletally immature tibial tubercle. (medscape.com)
Rhythmic repetitive movements are also fundamental in activities of daily living and require low levels of muscle force (gait, typewriting, etc). (nature.com)
For these reasons, we suggest that force and central drive to the muscle might not be key elements of neural adaptations of fatiguing repetitive movements. (nature.com)

A cramp is the involuntary contraction of our skeletal muscle, and it hurts. (theconversation.com)
Among the muscles are voluntary and involuntary muscles. (concordortho.com)
Involuntary muscles, or smooth muscles, are the ones that move on their own (for example, the muscles that control your diaphragm and help you breathe). (concordortho.com)
The muscles in your heart are called involuntary cardiac muscles. (concordortho.com)

Reproducibility of knee extensor and flexor contraction velocity in healthy men and women assessed using tensiomyography: A registered report. (plos.org)
Langen G, Lohr C, Ueberschär O, Behringer M (2022) Reproducibility of knee extensor and flexor contraction velocity in healthy men and women assessed using tensiomyography: A study protocol. (plos.org)
Spastic events are often velocity dependent, meaning the faster a limb is moving, the harsher the contraction, and this can cause feedback loops of spastic jerking during voluntary movement. (kif1a.org)
In this French study, a Compex Energy device was used to investigate the effect of a 5-week electrostimulation (EMS) training program on muscular strength (Quadriceps), kicking velocity, sprint, and vertical jump performance in soccer players. (compex.com)

Muscle Alive: Their Function Revealed by Electromyography. (sciepub.com)
Electromyography (EMG) sensors are generally used to record the electrical activity produced by skeletal muscles. (waset.org)

or a specific animal strain, to answer a research question-a specific muscle is identified based on its in vivo function and fibre type distribution. (wikipedia.org)
Gerdle B, Karlsson S, Crenshaw AG, Elert J, Fride J. The influences of muscle fibre proportions and areas upon EMG during maximal dynamic knee extensions. (sciepub.com)
Recruitment of fibre types and quadriceps muscle portions during repeated, intense knee-extensor exercise in humans. (biothema.com)
Krustrup P, Söderlund K, Relu M.U, Ferguson R.A, Bangsbo J. Heterogeneous recruitment of quadriceps muscle portions and fibre types during moderate intensity knee-extensor exercise:effect of thigh occlusion. (biothema.com)
An individual muscle fibre is a long cylindrical cell with multiple nuclei bound by its sarcolemma (Lutz and Lieber 1999). (musculoskeletalkey.com)
The sarcolemma invaginates around the muscle fibre forming T-tubules. (musculoskeletalkey.com)
Each muscle fibre contains a large number of myofibrils, which are the contractile elements of the muscle and consist of protein myofilaments. (musculoskeletalkey.com)
For this to occur, the muscle fibre is stimulated by a nerve impulse creating an action potential across the sarcolemma. (musculoskeletalkey.com)
Excessive force to a muscle fibre results in tearing of the sarcoplasm and the cells respond by forming a contraction band (condensation of cytoskeletal material) creating a protective barrier. (musculoskeletalkey.com)

Triceps surae muscle activation and tibialis anterior muscle co-activation were assessed by normalized root mean square of the EMG signal during the initial phase of contraction (0-100, 100-200 ms) and iMVC of the plantar flexors. (frontiersin.org)

In vitro muscle testing is a method used to characterize properties of living muscle tissue after removing it from an organism, which allows more extensive and precise quantification of its properties than in vivo testing. (wikipedia.org)
The entire muscle is bathed in Ringer's solution or Krebs-Henseleit solution with oxygen bubbling through in order to keep the tissue alive and metabolically active. (wikipedia.org)
All these have established that decreased skeletal muscle tissue indicators, together with low physical performance (all six guidelines) or muscle strength tests (EWGSOP, AWGS and FNIH), are necessary to establishing a diagnosis. (biomedcentral.com)
1] W. R. Frontera and J. Ochala, "Skeletal muscle: a brief review of structure and function," Calcified tissue international, vol. 96, no. 3, pp. 183-195, 2015. (waset.org)
Investigators currently employ a variety of established methods for answering such questions, but are often experimentally hampered by unique inherent heterogeneity between muscle groups and cells within the same muscle tissue. (biomedcentral.com)
These muscles are attached to bones by tendons , a sinewy type of tissue. (concordortho.com)

But only muscles actively being used tend to cramp, particularly those that cross more than one joint, such as the calf muscle and hamstrings. (theconversation.com)

Also, simultaneous NMES treatment on agonist/antagonist muscle can enhance the effect of preventing muscle atrophy. (biomedcentral.com)

Eccentric muscle actions (ECC) are characterized by muscle lengthening, despite actin-myosin crossbridge formation. (researchgate.net)
Strain injuries occur when muscle fibres cannot withstand excessive tensile forces placed on them and are therefore generally associated with eccentric muscle action (Mair et al. (musculoskeletalkey.com)
Eccentric contraction is the typical mechanism of injury, in which great tensions are developed and the muscle is susceptible to being injured 3 . (aspetar.com)
active lesions result from eccentric overloading to the muscle 5 . (aspetar.com)
Experimental knee pain impairs submaximal force steadiness in isometric, eccentric, and concentric muscle actions. (docksci.com)
Hence, it is important to take into consideration the concept of Herrera (2003) , where he states that plyometrics is that active expression of the muscles in which an eccentric-concentric contraction is performed as fast as possible, originating a muscular potential that depends on a manifestation of strength and speed. (sld.cu)

Interestingly, up to 50% of patients diagnosed with dysferlinopathy report a high degree of physical activity and good muscle prowess before the onset of symptoms. (medscape.com)

Each participant was seated on an isokinetic dynamometer, and a 40-min NMES treatment was applied to the quadriceps muscles of each leg 3x/week for 4 weeks with the stimulation frequency set at 60 Hz. (wku.edu)
Validity was determined using Spearman's correlation with isokinetic muscle strength. (biomedcentral.com)

Dm provides information on skeletal muscle stiffness, morphological and structural changes [ 2 - 4 ]. (plos.org)
Any fitness programme should include Electrical Muscle Stimulation (EMS) as an efficient way to passively workout and reduce stiffness. (tenscare.co.uk)

Mutations of Na V 1.4 give rise to a heterogeneous group of muscle disorders, with gain-of-function defects causing myotonia or hyperkalemic periodic paralysis. (jci.org)

The forearm muscles are weak and atrophic, with sparing of intrinsic hand muscles. (medscape.com)

Variable-frequency-train stimulation of skeletal muscle after spinal c" by C. Scott Bickel, Jill Slade et al. (gsu.edu)
When the muscle is tensed, or contracts, a reflexive message is sent to the spinal cord for the muscle to lengthen and relax. (theconversation.com)
So, in this instance, the muscle contracts, but the usual signal to the spinal cord for it to relax is inhibited. (theconversation.com)
When we tense our muscles a message is sent to the spinal cord for the muscles to relax. (theconversation.com)
In spasticity, the muscle-spinal cord circuits are hyperactive. (kif1a.org)
These signals can have an impact in the spinal cord or in the muscles. (kif1a.org)

Skeletal muscles are designed to produce voluntary movement by applying forces to bones and joints via a muscle contraction. (musculoskeletalkey.com)
These muscles all contain a relatively high percentage of type II fibres, are arranged in a pennate muscle architecture and cross two joints. (aspetar.com)
Long-term stretches are more likely to help: Spasticity depends on the speed of muscle movement, so keeping limbs stretched is less likely to cause contractions, while giving joints time to loosen up. (kif1a.org)

GNE myopathy is a condition that primarily affects skeletal muscles, which are muscles that the body uses for movement. (medlineplus.gov)
For individuals with GNE myopathy, foot drop is caused by weakness of a muscle in the lower leg called the tibialis anterior. (medlineplus.gov)
Unlike most forms of myopathy, GNE myopathy usually does not affect the quadriceps, which are a group of large muscles at the front of the thigh. (medlineplus.gov)
Weakness in leg muscles makes walking increasingly difficult, and most people with GNE myopathy require wheelchair assistance within 20 years after the signs and symptoms of the disorder appear. (medlineplus.gov)
Researchers are working to determine how a shortage of sialic acid leads to progressive muscle weakness in people with GNE myopathy. (medlineplus.gov)

Skeletal muscle is susceptible to a number of genetic, environmental, and age-related pathologies that impair the tissue's normal mechanical and metabolic function. (biomedcentral.com)

In isolated muscles, these tend to be muscles of the hind limbs, such as the soleus or EDL of mammals, or the plantaris or iliotibialis of amphibians. (wikipedia.org)

After 180 contractions (50% duty cycle), isometric peak torque decreased 44, 56, and 67 percent, in the AB (n = 10), acute SCI (n = 10), and chronic SCI (n = 12) groups, respectively. (gsu.edu)
In fatigued muscle, VFTs enhanced the torque-time integral by 18 percent in AB subjects and 6 percent in chronic SCI patients, and had no effect in acute SCI patients when compared to the corresponding CFT. (gsu.edu)

Ultrasound imaging is a valuable tool in exercise and sport science research, and has been used to visualize and track real-time movement of muscles and tendons, estimate hydration status in body tissues, and most recently, quantify skeletal muscle glycogen content. (biomedcentral.com)

The ability to assess skeletal muscle function and delineate regulatory mechanisms is essential to uncovering therapeutic approaches that preserve functional independence in a disease state. (biomedcentral.com)
To date, surprisingly few studies have taken advantage of the FDB to investigate mechanisms regulating skeletal muscle function. (biomedcentral.com)
The results highlight the experimental flexibility afforded the investigator by using the FDB muscle to assess mechanisms that regulate skeletal muscle function. (biomedcentral.com)
Defining the mechanisms that regulate the development of skeletal muscle dysfunction is critical for designing therapeutic interventions. (biomedcentral.com)

J Strength Cond Res 31(4): 869-881, 2017-Resistance training (RT) with nutritional strategies incorporating whey protein intake postexercise can stimulate muscle protein synthesis and elicit hypertrophy. (lww.com)
Muscle hypertrophy. (symptoma.com)

Phosphocreatine content in single fibres of human muscle after sustained submaximal exercise. (biothema.com)
Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans. (biothema.com)
Populations with knee joint damage, including arthritis, have noted impairments in the regulation of submaximal muscle force. (docksci.com)

Measured time courses of force decay during isometric contractions of rabbit M. gastrocnemius and M. plantaris were employed for model verification, with the finding that our suggested model enhancement proved eminently promising. (frontiersin.org)

Treatment with high-frequency NMES did not improve muscle endurance or related EMG parameters. (wku.edu)
The two most frequently reported parameters are the maximum displacement (Dm) and the contraction time (Tc) [ 1 ]. (plos.org)
After the first 3 weeks of EMS training there was a significant increase in muscle strength of the knee extensors as well as jumping performance, whereas the control group showed no changes in the same parameters. (compex.com)
The athletes were tested after 3 and 5 weeks training and at both assessments, they showed significant improvements in Quadriceps muscle strength parameters as well as in ball speed performance, while these improvements were not seen in the control group. (compex.com)

This is generally the same as athletes experiencing exercise-associated muscle cramps. (theconversation.com)
While EMS will give athletes a more effective muscle contraction than conventional training, it shouldn't be the exclusive means of strength training unless you're dealing with a rehab or joint wear-and-tear scenario. (tenscare.co.uk)
In exercise and sport science research, ultrasound imaging is used for a wide variety of applications including evaluation of the cardiovascular status of athletes, musculoskeletal pathology diagnosis and therapeutic interventions, and to visualize and track real-time movement of muscles and tendons [ 7 , 8 ]. (biomedcentral.com)
In this French study, the authors reviewed the literature with the purpose of giving an overview of the benefits and limitations of electrical muscle stimulation (EMS) in healthy individuals, recreational and competitive athletes. (compex.com)
There are several reasons why muscle cramps may occur, including the most common one that is seen in both professional and weekend athletes. (concordortho.com)

When a muscle is stretched, its signals are amplified to cause more intense contractions than necessary, which can override intentional movement originating in the brain. (kif1a.org)
Occasionally, cramps are so intense that you can't use your muscle because it's so tight and painful. (concordortho.com)

All patients have a history of progressive, proximal muscle weakness. (medscape.com)
In the limb-girdle presentation, pelvic and femoral muscles are affected first, with the proximal portions of the arms becoming weak later. (medscape.com)
Progressive proximal muscle weakness began again at age 8 years. (symptoma.com)

This disorder causes muscle weakness that appears in late adolescence or early adulthood and worsens over time. (medlineplus.gov)
As the disorder progresses, weakness also develops in the muscles of the upper legs, hips, shoulders, and hands. (medlineplus.gov)
Hypokalemic periodic paralysis (HypoPP) is an ion channelopathy of skeletal muscle characterized by attacks of muscle weakness associated with low serum K + . HypoPP results from a transient failure of muscle fiber excitability. (jci.org)
Limb girdle muscular dystrophy (LGMD) is a group of genetic muscle disorders which are mainly characterized by weakness and wasting of the muscles of the pelvic and pectoral girdles. (symptoma.com)
The first symptom to be noticed in LGMD is muscle weakness noticed as difficulty walking, carrying objects, lifting the arms, and an unstable gait . (symptoma.com)
Muscle biopsy is often helpful to determine if weakness is caused by muscular dystrophy, an inherited disorder, or by other acquired causes of muscle degeneration such as from inflammation or toxic exposure. (symptoma.com)
Generally, the first symptom that people with limb-girdle muscular dystrophy will notice is muscle weakness that causes trouble walking, resulting in a 'waddling' gait and difficulty climbing stairs or getting up from chairs. (symptoma.com)
treatments that reverse the muscle weakness . (symptoma.com)

It is possible that NMES induced adaptations may be frequency-specific and that high-frequency NMES may not be efficacious when the goal is to improve skeletal muscle endurance. (wku.edu)
Application of NMES has been consistently associated with increased mass, strength, and endurance of both normally and abnormally innervated muscles in a range of pathological conditions. (bmj.com)
Previously published studies on the effect of short-term endurance training on neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. (frontiersin.org)
This fitness retreat is for those who want to enhance their cardiovascular fitness, and improve muscle endurance, all under the guidance and assessment of our experts. (atmantan.com)

Greenhaff PL, Nevill M-E, Söderlund K, Bodin K, Boobis LH, Williams C and Hultman E. The metabolic responses of human type I and II muscle fibres during maximal treadmill sprinting. (biothema.com)
This pilot study conducted initial research into the bio mechanical responses of human muscles in various positions of salat. (waset.org)

MuscleSound® change scores acquired from an average of three ultrasound scans at the vastus lateralis site correlated significantly with change in vastus lateralis muscle glycogen content. (biomedcentral.com)

ICU patients without central and peripheral nerve injury were randomized into experimental group I (Exp I: active and passive activity training (APAT) + NMES treatment on the gastrocnemius and tibialis anterior muscle), experimental group II (Exp II: APAT + NMES treatment on gastrocnemius alone), and control group (Ctl: APAT alone). (biomedcentral.com)

During this stage of skeletal development, the Osgood-Schlatter lesion may occur. (medscape.com)
These "nocturnal" cramps occur with increasing frequency as we age, and are common in pregnancy. (theconversation.com)
Injuries to the muscle belly only occur with the application of very high forces. (musculoskeletalkey.com)
Muscle strains occur most often at the musculotendinous junction as a consequence of indirect trauma. (aspetar.com)
In this case, muscle strains, which are very common in sprinters and jumpers such as high jumpers, long jumpers, sprinters, long distance runners and tennis players, occur because of an indirect trauma and application of excessive tensile forces 6 . (aspetar.com)
Misdiagnosis as polymyositis can occur since inflammation can be present on muscle biopsy. (medscape.com)
Muscle cramps can also occur as a side effect of medications. (concordortho.com)

When pennate muscles are used, sonomicrometry is often used to accurately determine fiber length during the test. (wikipedia.org)

Methods: Fifteen patients with advanced COPD (nine men) were randomly assigned to either a home based 6 week quadriceps femoris NMES training programme (group 1, n=9, FEV 1 =38.0 (9.6)% of predicted) or a 6 week control period before receiving NMES (group 2, n=6, FEV 1 =39.5 (13.3)% of predicted). (bmj.com)

On the basis of bio-chemical kinetics, we present a model of muscle fiber exhaustion based on hydrolytic ATP-ADP-P i dynamics, which are assumed to be length- and calcium activity-dependent. (frontiersin.org)
This is particularly important when targeting fast-twitch muscle fiber, which you can preferentially target with the correct stimulation frequency to achieve greater physical power . (tenscare.co.uk)
Skeletal muscle provides distinct experimental challenges due to inherent differences across muscle groups, including fiber type and size that may limit experimental approaches. (biomedcentral.com)

Skeletal muscle mass is tightly regulated by the balance between the rates of muscle protein synthesis (MPS) and muscle protein breakdown (MPB) ( 11 ). (lww.com)
miR-424-5p reduces ribosomal RNA and protein synthesis in muscle wasting. (nih.gov)
Disturbance of consciousness, mechanical ventilation, use of glucocorticoids, insufficient nutritional intake, and so on are some of the factors that can reduce muscle protein synthesis and promote muscle protein decomposition in ICU patients. (biomedcentral.com)
This study further examined the time course for elevated muscle protein synthesis by examining its rate at 36 hrs following a training session. (researchgate.net)

Individualised pelvic floor muscle training in women with pelvic organ prolapse (POPPY): a multicentre randomised controlled trial. (oegpmr.at)

Gough JV, Ladley G. An investigation into the effectiveness of various forms of quadriceps exercises. (sciepub.com)

To move your muscles, your brain sends signals to the voluntary muscles and coordinates the movements that you want. (concordortho.com)

We aim to compare the effectiveness and safety of NMES to prevent muscle atrophy in intensive care unit (ICU) patients without nerve injury. (biomedcentral.com)
In addition to early exercise training, NMES should be applied to prevent muscle atrophy for patients without nerve injury in ICU. (biomedcentral.com)
Some scholars advocate that NMES should not be used when the patient's consciousness level is improved, and the patient can carry out autonomous activities [ 13 ], while other studies suggested that early active contraction combined with NMES can more alleviate muscle strength loss and atrophy through different modes of muscle activation [ 14 ]. (biomedcentral.com)

Agonist/Antagonist and medial/lateral muscle activity is not different between men and women when they are strength matched. (jssm.org)
If you plan to use EMS as a sole means of eliciting strength gains in muscle, you can be certain you will get a more effective muscle contraction-albeit using an appropriate amount of current-than when training three times per week. (tenscare.co.uk)
Clinical and functional assessment shows muscle strength and high speed/high resistance athletic activities are impaired with marked loss of muscle function. (aspetar.com)
Dynamic knee extensor muscle strength is a valid measure among healthy older adults but has not been tested in the sarcopenia condition. (biomedcentral.com)
The estimated measure of bilateral knee extension muscle strength can be used to monitor adaptations promoted by physical exercise for older adults with and without sarcopenia. (biomedcentral.com)
8] M. F. Maia, J. M. Willardson, G. A. Paz, and H. Miranda, "Effects of different rest intervals between antagonist paired sets on repetition performance and muscle activation," The Journal of Strength & Conditioning Research, vol. 28, no. 9, pp. 2529-2535, 2014. (waset.org)
such is the case of the reactive manifestation: which is nothing more than the strength generated by the muscle as a reaction to an external strength that modifies or alters its own structure. (sld.cu)
EMS training results in significant increase of muscle strength. (compex.com)
In this French study, a Compex Sport device was used to investigate the effects of a 6-week combined electrical muscle stimulation (EMS) and gymnastic training program on muscle strength and vertical jump performance of prepubertal gymnasts. (compex.com)

Anatomy60

Organisms17

Diseases19

Chemicals and Drugs63

Analytical, Diagnostic and Therapeutic Techniques and Equipment30

Psychiatry and Psychology3

Phenomena and Processes70

Disciplines and Occupations2

Anthropology, Education, Sociology and Social Phenomena8

Information Science3

Health Care2

Femoris muscle2

Fatigue41

Human skeletal muscle2

Electrical stimulation10

Isometric contraction2

Biceps6

Maximal voluntary isometric2

Distal5

Physiology1

Fibers7

Maximum voluntary2

Lower limb muscles2

Commonly6

Ankle5

Repetitive3

Involuntary4

Velocity4

Electromyography2

Fibre9

Triceps1

Tissue6

Hamstrings1

Agonist-antagonist muscle1

Eccentric6

Onset of symptoms1

Isokinetic2

Stiffness2

Heterogeneous1

Intrinsic hand muscles1

Spinal6

Joints3

Myopathy5

Susceptible1

Soleus1

Torque2

Quantify1

Mechanisms4

Hypertrophy2

Submaximal3

Plantaris1

Parameters4

Athletes5

Intense2

Proximal3

Weakness8

Endurance4

Responses2

Vastus latera1

Tibialis anteri1

Occur7

Pennate1

Programme1

Fiber3

Protein synthesis4

Pelvic1

Exercises1

Signals1

NMES3

Strength9