Twitch potentiation is greater after a fatiguing submaximal isometric contraction performed at short vs. long quadriceps muscle length

2005 ◽  
Vol 98 (2) ◽  
pp. 429-436 ◽  
Author(s):  
Nicolas Place ◽  
Nicola A. Maffiuletti ◽  
Yves Ballay ◽  
Romuald Lepers
Keyword(s):  
Isometric Contraction ◽  
Muscle Length ◽  
Knee Extensor ◽  
Central Fatigue ◽  
Short Length ◽  
Voluntary Activation ◽  
Full Extension ◽  
Endurance Time ◽  
Task Failure ◽  
Twitch Potentiation

Endurance time of a submaximal sustained contraction is longer when the muscle is fatigued in a shortened position. The aim of the present study was to compare central and peripheral mechanisms of fatigue after an isometric contraction of the knee extensor muscles performed at 20% maximal voluntary contraction (MVC) at two knee angles (35°, short length vs. 75°, long length; 0° = full extension) until exhaustion. Eleven men (24 ± 4 yr) attended two experimental randomized sessions. Endurance time was greater at 35° compared with 75° (974 ± 457 vs. 398 ± 144 s; P < 0.001) despite a similar reduction in knee extensor MVC (−28.4 ± 16.0%, P < 0.001 vs. −27.6 ± 18.8%, P < 0.001, respectively). Voluntary activation level was similarly depressed after the fatiguing contraction performed at the two muscle lengths (−19 ± 16.7% at 35°, P < 0.01 vs. −13.7 ± 14.5% at 75°, P < 0.01). After the fatiguing contraction, peak twitch potentiation was observed only at the short length (+31.8 ± 17.6% at 35°, P < 0.01 vs. +6.4 ± 21.3% at 75°, P > 0.05), whereas M-wave properties were similarly altered for the two angles. These results suggest that 1) central fatigue at task failure for a sustained isometric contraction was not dependent on the muscle length, and 2) the longer endurance time of a sustained isometric contraction performed at a shortened length is related to potentiation. It is suggested that the greater endurance time of a sustained isometric contraction observed at 35° is related to the occurrence of potentiation at this short length, because central fatigue is similar at task failure for both tasks.

scholarly journals Acute effect of tendon vibration applied during isometric contraction at two knee angles on maximal knee extension force production

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242324
Author(s):  
Jonathan Harnie ◽  
Thomas Cattagni ◽  
Christophe Cornu ◽  
Peter McNair ◽  
Marc Jubeau
Keyword(s):  
Isometric Contraction ◽  
Vastus Lateralis ◽  
Force Production ◽  
Knee Extensor ◽  
Acute Effect ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Tendon Vibration ◽  
Knee Angle

The aim of the current study was to investigate the effect of a single session of prolonged tendon vibration combined with low submaximal isometric contraction on maximal motor performance. Thirty-two young sedentary adults were assigned into two groups that differed based on the knee angle tested: 90° or 150° (180° = full knee extension). Participants performed two fatigue-inducing exercise protocols: one with three 10 min submaximal (10% of maximal voluntary contraction) knee extensor contractions and patellar tendon vibration (80 Hz) another with submaximal knee extensor contractions only. Before and after each fatigue protocol, maximal voluntary isometric contractions (MVC), voluntary activation level (assessed by the twitch interpolation technique), peak-to-peak amplitude of maximum compound action potentials of vastus medialis and vastus lateralis (assessed by electromyography with the use of electrical nerve stimulation), peak twitch amplitude and peak doublet force were measured. The knee extensor fatigue was significantly (P<0.05) greater in the 90° knee angle group (-20.6% MVC force, P<0.05) than the 150° knee angle group (-8.3% MVC force, P = 0.062). Both peripheral and central alterations could explain the reduction in MVC force at 90° knee angle. However, tendon vibration added to isometric contraction did not exacerbate the reduction in MVC force. These results clearly demonstrate that acute infrapatellar tendon vibration using a commercial apparatus operating at optimal conditions (i.e. contracted and stretched muscle) does not appear to induce knee extensor neuromuscular fatigue in young sedentary subjects.

scholarly journals Child-adult differences in neuromuscular fatigue are muscle dependent

2018 ◽  
Vol 125 (4) ◽  
pp. 1246-1256 ◽  
Author(s):  
Enzo Piponnier ◽  
Vincent Martin ◽  
Bastien Bontemps ◽  
Emeric Chalchat ◽  
Valérie Julian ◽  
...  
Keyword(s):  
Near Infrared ◽  
Knee Extensor ◽  
Central Fatigue ◽  
Neuromuscular Fatigue ◽  
Muscle Group ◽  
Voluntary Activation ◽  
Peripheral Fatigue ◽  
Plantar Flexor ◽  
Significant Difference ◽  
Lower Extent

The aim of the present study was to compare the development and etiology of neuromuscular fatigue of the knee extensor (KE) and plantar flexor (PF) muscles during repeated maximal voluntary isometric contractions (MVICs) between children and adults. Prepubertal boys ( n = 21; 9–11 yr) and men ( n = 24; 18–30 yr) performed two fatigue protocols consisting of a repetition of 5-s isometric MVIC of the KE or PF muscles interspersed with 5-s passive recovery periods until MVIC reached 60% of its initial value. The etiology of neuromuscular fatigue of the KE and PF muscles was investigated by means of noninvasive methods, such as the surface electromyography, single and doublet magnetic stimulation, twitch interpolation technique, and near-infrared spectroscopy. The number of repetitions performed was significantly lower in men (15.4 ± 3.8) than boys (38.7 ± 18.8) for the KE fatigue test. In contrast, no significant difference was found for the PF muscles between boys and men (12.1 ± 4.9 and 13.8 ± 4.9 repetitions, respectively). Boys displayed a lower reduction in potentiated twitch torque, low-frequency fatigue, and muscle oxygenation than men whatever the muscle group considered. In contrast, voluntary activation level and normalized electromyography data decreased to a greater extent in boys than men for both muscle groups. To conclude, boys experienced less peripheral and more central fatigue during repeated MVICs than men whatever the muscle group considered. However, child-adult differences in neuromuscular fatigue were muscle-dependent since boys fatigued similarly to men with the PF muscles and to a lower extent with the KE muscles. NEW & NOTEWORTHY Child-adult differences in neuromuscular fatigue during repeated maximal voluntary contractions are specific to the muscle group since children fatigue similarly to adults with the plantar flexor muscles and to a lower extent with the knee extensor muscles. Children experience less peripheral fatigue and more central fatigue than adults, regardless of the muscle group considered.

scholarly journals Hyperthermia and central fatigue during prolonged exercise in humans

2001 ◽  
Vol 91 (3) ◽  
pp. 1055-1060 ◽  
Author(s):  
Lars Nybo ◽  
Bodil Nielsen
Keyword(s):  
Core Temperature ◽  
Maximal Oxygen Consumption ◽  
Knee Extensor ◽  
Central Fatigue ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Knee Extensors ◽  
Total Force ◽  
Impaired Performance

The present study investigated the effects of hyperthermia on the contributions of central and peripheral factors to the development of neuromuscular fatigue. Fourteen men exercised at 60% maximal oxygen consumption on a cycle ergometer in hot (40°C; hyperthermia) and thermoneutral (18°C; control) environments. In hyperthermia, the core temperature increased throughout the exercise period and reached a peak value of 40.0 ± 0.1°C (mean ± SE) at exhaustion after 50 ± 3 min of exercise. In control, core temperature stabilized at ∼38.0 ± 0.1°C, and exercise was maintained for 1 h without exhausting the subjects. Immediately after the cycle trials, subjects performed 2 min of sustained maximal voluntary contraction (MVC) either with the exercised legs (knee extension) or with a “nonexercised” muscle group (handgrip). The degree of voluntary activation during sustained maximal knee extensions was assessed by superimposing electrical stimulation (EL) to nervus femoralis. Voluntary knee extensor force was similar during the first 5 s of contraction in hyperthermia and control. Thereafter, force declined in both trials, but the reduction in maximal voluntary force was more pronounced in the hyperthermic trial, and, from 30 to 120 s, the force was significantly lower in hyperthermia compared with control. Calculation of the voluntary activation percentage (MVC/MVC + EL) revealed that the degree of central activation was significantly lower in hyperthermia (54 ± 7%) compared with control (82 ± 6%). In contrast, total force of the knee extensors (MVC + force from EL) was not different in the two trials. Force development during handgrip contraction followed the same pattern of response as was observed for the knee extensors. In conclusion, these data demonstrate that the ability to generate force during a prolonged MVC is attenuated with hyperthermia, and the impaired performance is associated with a reduction in the voluntary activation percentage.

Exercising muscle mass influences neuromuscular, cardiorespiratory, and perceptual responses during and following ramp incremental cycling to task failure

2021 ◽  
Author(s):  
Jenny Zhang ◽  
Danilo Iannetta ◽  
Mohammed Alzeeby ◽  
Martin J. MacInnis ◽  
Saied Jalal Aboodarda
Keyword(s):  
Muscle Mass ◽  
Perceived Exertion ◽  
Central Fatigue ◽  
Exercise Duration ◽  
Peak Oxygen Uptake ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Peak Power Output ◽  
Task Failure ◽  
Single Twitch

Neuromuscular (NM), cardiorespiratory, and perceptual responses to maximal graded exercise using different amounts of active muscle mass remain unclear. We hypothesized that during dynamic exercise, peripheral NM fatigue (declined twitch force) and muscle pain would be greater using smaller muscle mass, whereas central fatigue (declined voluntary activation) and ventilatory variables would be greater using larger muscle mass. Twelve males (29.8±4.7 years) performed two cycling ramp incremental tests until task failure: (i) single-leg (SL) with 10 W·min-1ramp, and (ii) double-leg (DL) with 20 W·min-1ramp. NM fatigue was assessed at baseline, task failure (post), then after 1, 4, and 8 min of recovery. Cardiorespiratory and perceptual variables (i.e., ratings of perceived exertion (RPE), fatigue, pain, dyspnea) were measured throughout cycling. Exercise duration was similar between sessions (SL: 857.7±263.6; DL: 855.0±218.8 s; p=0.923) and higher absolute peak power output was attained in DL (SL: 163.2±43.8; DL: 307.0±72.0 W; p<0.001). While central fatigue did not differ between conditions (SL: -6.6±6.5%; DL: -3.5±4.8%; p=0.091), maximal voluntary contraction (SL: -41.6±10.9%; DL: -33.7±8.5%; p=0.032) and single twitch forces (SL: -59.4±18.8%; DL: -46.2±16.2%; p=0.003) declined more following SL. DL elicited higher peak oxygen uptake (SL: 42.1±10.0; DL:50.3±9.3 mL·kg-1·min-1; p<0.001), ventilation (SL: 137.1±38.1; DL: 171.5±33.2 L·min-1; p<0.001), and heart rate (SL: 167±21; DL: 187±8 bpm; p=0.005). Dyspnea (p=0.025) was higher in DL; however, RPE (p=0.005) and pain (p<0.001) were higher in SL. These results suggest that interplay between NM, cardiorespiratory, and perceptual determinants of exercise performance during incremental cycling to task failure are muscle mass-dependent.

Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions

2001 ◽  
Vol 91 (6) ◽  
pp. 2628-2634 ◽  
Author(s):  
Nicolas Babault ◽  
Michel Pousson ◽  
Yves Ballay ◽  
Jacques Van Hoecke
Keyword(s):  
Femoral Nerve ◽  
Knee Extensor ◽  
Muscle Group ◽  
Extensor Muscle ◽  
Voluntary Activation ◽  
Eccentric Contractions ◽  
Full Extension ◽  
Concentric Contractions ◽  
Activation Level ◽  
The Right

Maximal and submaximal activation level of the right knee-extensor muscle group were studied during isometric and slow isokinetic muscular contractions in eight male subjects. The activation level was quantified by means of the twitch interpolation technique. A single electrical impulse was delivered, whatever the contraction mode, on the femoral nerve at a constant 50° knee flexion (0° = full extension). Concentric, eccentric (both at 20°/s velocity), and isometric voluntary activation levels were then calculated. The mean activation levels during maximal eccentric and maximal concentric contractions were 88.3 and 89.7%, respectively, and were significantly lower ( P < 0.05) with respect to maximal isometric contractions (95.2%). The relationship between voluntary activation levels and submaximal torques was linearly fitted ( P < 0.01): comparison of slopes indicated lower activation levels during submaximal eccentric compared with isometric or concentric contractions. It is concluded that reduced neural drive is present during 20°/s maximal concentric and both maximal and submaximal eccentric contractions. These results indicate a voluntary activation dependency on both tension levels and type of muscular actions in the human knee-extensor muscle group.

Mechanisms contributing to knee extensor strength loss after prolonged running exercise

2003 ◽  
Vol 94 (1) ◽  
pp. 193-198 ◽  
Author(s):  
G. Y. Millet ◽  
V. Martin ◽  
G. Lattier ◽  
Y. Ballay
Keyword(s):  
Mechanical Response ◽  
Vastus Lateralis ◽  
Femoral Nerve ◽  
Knee Extensor ◽  
Central Fatigue ◽  
Strength Loss ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Running Exercise ◽  
Highly Correlated

The aim of this study was to identify the mechanisms that contribute to the decline in knee extensor (KE) muscles strength after a prolonged running exercise. During the 2 days preceding a 30-km running race [duration 188.7 ± 27.0 (SD) min] and immediately after the race, maximal percutaneous electrical stimulations (single twitch, 0.5-s tetanus at 20 and 80 Hz) were applied to the femoral nerve of 12 trained runners. Superimposed twitches were also delivered during isometric maximal voluntary contraction (MVC) to determine the level of voluntary activation (%VA). The vastus lateralis electromyogram was recorded. KE MVC decreased from pre- to postexercise (from 188.1 ± 25.2 to 142.7 ± 29.7 N · m; P < 0.001) as did %VA (from 98.8 ± 1.8 to 91.3 ± 10.7%; P < 0.05). The changes from pre- to postexercise in these two variables were highly correlated ( R = 0.88; P < 0.001). The modifications in the mechanical response after the 80-Hz stimulation and M-wave peak-to-peak amplitude were also significant ( P < 0.001 and P < 0.05, respectively). It can be concluded that 1) central fatigue, neuromuscular propagation, and muscular factors are involved in the 23.5 ± 14.9% reduction in MVC after a prolonged running bout at racing pace and 2) runners with the greatest KE strength loss experience large activation deficit.

scholarly journals Effect of Uni and Bilateral High-Intensity Sustained Isometric Contraction Exercise on Fatigue Related Changes in Quadriceps Femoris

2020 ◽  
Vol 2 (117) ◽  
Author(s):  
Giedrė Jurgelaitienė ◽  
Andrius Šatas ◽  
Dalia Mickevičienė ◽  
Albertas Skurvydas
Keyword(s):  
Isometric Contraction ◽  
High Intensity ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Muscle Length ◽  
Central Fatigue ◽  
Voluntary Contraction ◽  
Capillary Blood ◽  
Peripheral Fatigue

Background. It is well established that different types of exercise can provide central and peripheral fatigue. However, there are conflicting findings in the literature, and a consensus has not been reached regarding the different patterns of different ways of performing exercises when the muscle works at long and short lengths and unilaterally and bilaterally. The purpose of this study was to investigate the effect of muscle length and the high-intensity physical exercise when performing unilaterally and bilaterally on fatigue.Methods. Thirteen young healthy physically active volunteering males participated in the study.  Maximal voluntary and involuntary contraction was observed during the performance of sustained maximal (uni-)bilateral isometric contraction at long and short quadriceps muscle length. Capillary blood lactate concentration and perceived exertion was observed after high-intensity physical exercise.Results. Maximal voluntary contraction (MVC)% decreased significantly and greatly in (uni-)bilateral exercise at long muscle length. CAR% at the appearance of fatigue was greater at long muscle length and did not depend on (uni-)bilateral contraction.Conclusion. When both legs generate force (bilateral contraction), it is possible to observe a decrease in the rate of force development (RFD) but not in the MVC. Movement performed at long muscle length and (uni-)bilaterally has an effect on a greater motor cortex activation and a sense of movement effort and lactate concentration in capillary blood. Keywords: high intensity interval exercise, sustained isometric contraction, central fatigue, peripheral fatigue, bilateral and unilateral contraction.

Distinct profiles of neuromuscular fatigue during muscle contractions below and above the critical torque in humans

2012 ◽  
Vol 113 (2) ◽  
pp. 215-223 ◽  
Author(s):  
Mark Burnley ◽  
Anni Vanhatalo ◽  
Andrew M. Jones
Keyword(s):  
Vastus Lateralis ◽  
Central Fatigue ◽  
Neuromuscular Fatigue ◽  
Voluntary Activation ◽  
Peripheral Fatigue ◽  
Critical Threshold ◽  
Task Failure ◽  
Fatigue Development ◽  
The Right ◽  
Experimental Trials

Whether the transition in fatigue processes between “low-intensity” and “high-intensity” contractions occurs gradually, as the torque requirements are increased, or whether this transition occurs more suddenly at some identifiable “threshold”, is not known. We hypothesized that the critical torque (CT; the asymptote of the torque-duration relationship) would demarcate distinct profiles of central and peripheral fatigue during intermittent isometric quadriceps contractions (3-s contraction, 2-s rest). Nine healthy men performed seven experimental trials to task failure or for up to 60 min, with maximal voluntary contractions (MVCs) performed at the end of each minute. The first five trials were performed to determine CT [∼35–55% MVC, denoted severe 1 (S1) to severe 5 (S5) in ascending order], while the remaining two trials were performed 10 and 20% below the CT (denoted CT-10% and CT-20%). Dynamometer torque and the electromyogram of the right vastus lateralis were sampled continuously. Peripheral and central fatigue was determined from the fall in potentiated doublet torque and voluntary activation, respectively. Above CT, contractions progressed to task failure in ∼3–18 min, at which point the MVC did not differ from the target torque (S1 target, 88.7 ± 4.3 N·m vs. MVC, 89.3 ± 8.8 N·m, P = 0.94). The potentiated doublet fell significantly in all trials, and voluntary activation was reduced in trials S1–S3, but not trials S4 and S5. Below CT, contractions could be sustained for 60 min on 17 of 18 occasions. Both central and peripheral fatigue developed, but there was a substantial reserve in MVC torque at the end of the task. The rate of global and peripheral fatigue development was four to five times greater during S1 than during CT-10% (change in MVC/change in time S1 vs. CT-10%: −7.2 ± 1.4 vs. −1.5 ± 0.4 N·m·min−1). These results demonstrate that CT represents a critical threshold for neuromuscular fatigue development.

scholarly journals Effect of the Knee and Hip Angles on Knee Extensor Torque: Neural, Architectural, and Mechanical Considerations

2022 ◽  
Vol 12 ◽  
Author(s):  
Yoann M. Garnier ◽  
Romuald Lepers ◽  
Patrizio Canepa ◽  
Alain Martin ◽  
Christos Paizis
Keyword(s):  
Knee Flexion ◽  
Muscle Activation ◽  
Mutual Influence ◽  
Vastus Lateralis ◽  
Muscle Length ◽  
Knee Extensor ◽  
Muscular Activity ◽  
Pennation Angle ◽  
Knee Extensors ◽  
Full Extension

This study examined the influence of knee extensors’ hip and knee angle on force production capacity and their neuromuscular and architectural consequences. Sixteen healthy men performed sub-maximal and maximal voluntary isometric contractions (MVIC) of knee extensors with four different combinations of the knee and hip angles. Muscle architecture, excitation-contraction coupling process, muscular activity, and corticospinal excitability were evaluated on the vastus lateralis (VL) and rectus femoris (RF) muscles. MVIC and evoked peak twitch (Pt) torques of knee extensors increased significantly (p &lt; 0.05) by 42 ± 12% and 47 ± 16% on average, respectively, under knee flexed positions (110° flexion, 0° = full extension) compared to knee extended positions (20° flexion) but were not different between hip positions (i.e., 0° or 60° flexion). Knee flexion also affected VL and RF muscle and fascicle lengths toward greater length than under knee extended position, while pennation angle decreased for both muscles with knee flexion. Pennation angles of the VL muscle were also lower under extended hip positions. Alternatively, no change in maximal muscle activation or corticospinal activity occurred for the VL and RF muscles across the different positions. Altogether these findings evidenced that MVIC torque of knee extensors depended particularly upon peripheral contractile elements, such as VL and RF muscle and fascicle lengths, but was unaffected by central factors (i.e., muscle activation). Furthermore, the hip position can affect the pennation angle of the VL, while VL muscle length can affect the pennation angle of the RF muscle. These elements suggest that the VL and RF muscles exert a mutual influence on their architecture, probably related to the rectus-vastus aponeurosis.

scholarly journals Supraspinal fatigue impedes recovery from a low-intensity sustained contraction in old adults

2012 ◽  
Vol 112 (5) ◽  
pp. 849-858 ◽  
Author(s):  
Tejin Yoon ◽  
Bonnie Schlinder-Delap ◽  
Manda L. Keller ◽  
Sandra K. Hunter
Keyword(s):  
Young Adults ◽  
Pressor Response ◽  
Motor Evoked Potential ◽  
Silent Period ◽  
Voluntary Activation ◽  
Age Difference ◽  
Task Failure ◽  
Old Adults ◽  
Sustained Contraction ◽  
Low Intensity

This study determined the contribution of supraspinal fatigue and contractile properties to the age difference in neuromuscular fatigue during and recovery from a low-intensity sustained contraction. Cortical stimulation was used to evoke measures of voluntary activation and muscle relaxation during and after a contraction sustained at 20% of maximal voluntary contraction (MVC) until task failure with elbow flexor muscles in 14 young adults (20.9 ± 3.6 yr, 7 men) and 14 old adults (71.6 ± 5.4 yr, 7 men). Old adults exhibited a longer time to task failure than the young adults (23.8 ± 9.0 vs. 11.5 ± 3.9 min, respectively, P < 0.001). The time to failure was associated with initial peak rates of relaxation of muscle fibers and pressor response ( P < 0.05). Increments in torque (superimposed twitch; SIT) generated by transcranial magnetic stimulation (TMS) during brief MVCs, increased during the fatiguing contraction ( P < 0.001) and then decreased during recovery ( P = 0.02). The increase in the SIT was greater for the old adults than the young adults during the fatiguing contraction and recovery ( P < 0.05). Recovery of MVC torque was less for old than young adults at 10 min post-fatiguing contraction (75.1 ± 8.7 vs. 83.6 ± 7.8% of control MVC, respectively, P = 0.01) and was associated with the recovery of the SIT ( r = −0.59, r2 = 0.35, P < 0.001). Motor evoked potential (MEP) amplitude and the silent period elicited during the fatiguing contraction increased less for old adults than young adults ( P < 0.05). The greater fatigue resistance with age during a low-intensity sustained contraction was attributable to mechanisms located within the muscle. Recovery of maximal strength after the low-intensity fatiguing contraction however, was impeded more for old adults than young because of greater supraspinal fatigue. Recovery of strength could be an important variable to consider in exercise prescription of old populations.

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