Resting shear elastic modulus as a marker of peripheral fatigue during maximal isometric contractions in humans

AbstractThe aim of this study was to investigate whether the resting Vastus Lateralis (VL) muscle shear elastic modulus (µ), evaluated by shear wave elastography, represents peripheral fatigue during repetition of isometric maximal voluntary contractions (MVCs) of the knee extensor (KE) muscles.Eight healthy well-trained males repeated 60 isometric MVCs of the KE muscles (6 × 10 MVCs; 5 s on/5 s off). Single and double electrical stimulations were delivered to the femoral nerve every ten MVCs during contraction and at rest. The amplitude and properties of the potentiated torque following single (Twpot) double electrostimulation and the amplitude of the concomitant VL compound action potential were considered to be indicators of peripheral fatigue. The resting VLµ was measured during a 5-s rest period after each MVC and electrical stimulation series.The resting VLµ significantly decreased (-21.8 ± 3.9%; P < 0.001) by the end of the fatigue protocol, decreasing from the 10th MVC to the end of the exercise (60th MVC) for all participants, with the loss ranging from 18 to 29%. The potentiated doublet and single twitch torque (Twpot) decreased by 42.5 ± 10.8% and 55.7 ± 8.8%, respectively, by the end of exercise (P < 0.001 for both). The relative mechanical properties of Twpot, i.e. electromechanical delay (P <0 .001), contraction time (P = 0.004), and maximal rate of torque development/relaxation (P < 0.001) also changed significantly during exercise.This study shows that the kinetics of the resting VLµ is associated with changes in both voluntary and electrostimulated torque amplitudes and electromechanical properties of the single twitch during the repetition of maximal voluntary fatiguing exercise. Changes in the resting VLµ may reflect a decline in muscle function, e.g. impairment of excitation-contraction coupling, contractile processes, and/or elastic properties, throughout the increase in muscle compliance, directly affecting force transmission.

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Change in Shear Elastic Modulus of Thigh Muscle by Changing Muscle Length Using Ultrasound Shear Wave Elastography in Beagle Dogs

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0039-1692449 ◽

2019 ◽

Vol 32 (06) ◽

pp. 454-459 ◽

Cited By ~ 2

Author(s):

Miki Shimizu ◽

Yu Ito

Keyword(s):

Elastic Modulus ◽

Shear Wave ◽

Vastus Lateralis ◽

Muscle Length ◽

Shear Wave Elastography ◽

Biceps Femoris ◽

Percentage Change ◽

Thigh Muscle ◽

Beagle Dogs ◽

Shear Elastic Modulus

Objectives This study investigated the relationship between the change in the shear elastic modulus and the change in muscle length using ultrasound shear wave elastography. Study Design Four thigh muscles, cranial part of the sartorius, vastus lateralis, biceps femoris and semitendinosus muscles, of 21 pelvic limbs in 12 clinically healthy Beagle dogs were used. The muscle length was estimated using a radiograph and the flexed and extended positions of the coxofemoral and stifle joints, respectively. The shear elastic modulus (kPa) was measured in two joint positions using ultrasound shear wave elastography. Shear elastic modulus was expressed as median of 10 consecutive measurements. The percentage change of elastic modulus was calculated from the shear elastic modulus in elongated condition and pre-elongated condition of muscle. Results The elastic modulus of all muscles increased when the muscle was elongated. The shear elastic modulus for both joint positions and the percentage change of the shear elastic modulus (%) in cranial part of the sartorius were highest in all muscles. Intra-observer correlation coefficient (1.2) was 0.75 to 0.96 and intra-observer correlation coefficients (2.2) was 0.46 to 0.96. Conclusion This study revealed that the shear elastic modulus of muscle was changed by the change in muscle length and increased when the muscle was elongated. Ultrasound shear wave elastography can be used to assess the elastic properties of canine muscle.

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Etiology of Neuromuscular Fatigue After Repeated Sprints Depends on Exercise Modality

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2016-0200 ◽

2017 ◽

Vol 12 (7) ◽

pp. 878-885 ◽

Cited By ~ 11

Author(s):

Katja Tomazin ◽

Jean-Benoit Morin ◽

Guillaume Y. Millet

Keyword(s):

Vastus Lateralis ◽

Knee Extensor ◽

Compound Action Potential ◽

Neuromuscular Fatigue ◽

Voluntary Activation ◽

Peak Power Output ◽

Peripheral Fatigue ◽

M Wave ◽

Sprint Running ◽

Repeated Sprint

Purpose:To compare neuromuscular fatigue induced by repeated-sprint running vs cycling.Methods:Eleven active male participants performed 2 repeated-maximal-sprint protocols (5×6 s, 24-s rest periods, 4 sets, 3 min between sets), 1 in running (treadmill) and 1 in cycling (cycle ergometer). Neuromuscular function, evaluated before (PRE); 30 s after the first (S1), the second (S2), and the last set (LAST); and 5 min after the last set (POST5) determined the knee-extensor maximal voluntary torque (MVC); voluntary activation (VA); single-twitch (Tw), high- (Db100), and low- (Db10) frequency torque; and maximal muscle compound action potential (M-wave) amplitude and duration of vastus lateralis.Results:Peak power output decreased from 14.6 ± 2.2 to 12.4 ± 2.5 W/kg in cycling (P < .01) and from 21.4 ± 2.6 to 15.2 ± 2.6 W/kg in running (P < .001). MVC declined significantly from S1 in running but only from LAST in cycling. VA decreased after S2 (~–7%, P < .05) and LAST (~–9%, P < .01) set in repeated-sprint running and did not change in cycling. Tw, Db100, and Db10/Db100 decreased to a similar extent in both protocols (all P < .001 post-LAST). Both protocols induced a similar level of peripheral fatigue (ie, low-frequency peripheral fatigue, no changes in M-wave characteristics), while underlying mechanisms probably differed. Central fatigue was found only after running.Conclusion:Findings about neuromuscular fatigue resulting from RS cycling cannot be transferred to RS running.

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Effect of vastus lateralis fatigue on load sharing between quadriceps femoris muscles during isometric knee extensions

Journal of Neurophysiology ◽

10.1152/jn.00595.2013 ◽

2014 ◽

Vol 111 (4) ◽

pp. 768-776 ◽

Cited By ~ 40

Author(s):

Killian Bouillard ◽

Marc Jubeau ◽

Antoine Nordez ◽

François Hug

Keyword(s):

Elastic Modulus ◽

Vastus Lateralis ◽

Shear Wave Elastography ◽

Rectus Femoris ◽

Load Sharing ◽

Knee Extension ◽

Voluntary Contraction ◽

Control Session ◽

Shear Elastic Modulus ◽

Control Load

The present study aimed to investigate the effects of selective fatigue (i.e., one muscle of the quadriceps) on load sharing strategies during submaximal knee extensions. Shear wave elastography was used to measure muscle shear elastic modulus, as this is considered to be an index of individual muscle force. Sixteen participants attended two experimental sessions that each involved six 10-s knee extensions at 20% of maximal voluntary contraction (MVC) followed by a sustained submaximal isometric knee extension at 20% of MVC, until task failure (Tlim). Between the 10-s contractions and Tlim, participants were required to rest (5 min) for the control session or underwent 5 min of electromyostimulation (EMS) on vastus lateralis (EMS session). Compared with the control session, vastus lateralis shear elastic modulus values were significantly lower after EMS considering both the start of Tlim (54.6 ± 11.8 vs. 68.4 ± 19.2 kPa; P = 0.011) and the entire Tlim contraction (59.0 ± 14.0 vs. 74.4 ± 20.3 kPa; P = 0.019). However, no significant differences were observed for the other recorded muscles (vastus medialis and rectus femoris; both P = 1), i.e., different patterns of changes were found between participants. In conclusion, this study demonstrates that prefatiguing a single agonist muscle does not lead to a consistent redistribution of load sharing among the quadriceps muscles between individuals. These results suggest that the central nervous system does not use a common principle among individuals to control load sharing when neuromuscular fatigue occurs.

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The role of active muscle mass in determining the magnitude of peripheral fatigue during dynamic exercise

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00043.2014 ◽

2014 ◽

Vol 306 (12) ◽

pp. R934-R940 ◽

Cited By ~ 39

Author(s):

Matthew J. Rossman ◽

Ryan S. Garten ◽

Massimo Venturelli ◽

Markus Amann ◽

Russell S. Richardson

Keyword(s):

Muscle Mass ◽

Vastus Lateralis ◽

Femoral Nerve ◽

Afferent Feedback ◽

Whole Body ◽

Peripheral Fatigue ◽

Group Iii ◽

Task Specificity ◽

Peripheral Muscle ◽

Small Muscle

Greater peripheral quadriceps fatigue at the voluntary termination of single-leg knee-extensor exercise (KE), compared with whole-body cycling, has been attributed to confining group III and IV skeletal muscle afferent feedback to a small muscle mass, enabling the central nervous system (CNS) to tolerate greater peripheral fatigue. However, as task specificity and vastly differing systemic challenges may have complicated this interpretation, eight males were studied during constant workload trials to exhaustion at 85% of peak workload during single-leg and double-leg KE. It was hypothesized that because of the smaller muscle mass engaged during single-leg KE, a greater magnitude of peripheral quadriceps fatigue would be present at exhaustion. Vastus lateralis integrated electromyogram (iEMG) signal relative to the first minute of exercise, preexercise to postexercise maximal voluntary contractions (MVCs) of the quadriceps, and twitch-force evoked by supramaximal magnetic femoral nerve stimulation (Qtw,pot) quantified peripheral quadriceps fatigue. Trials performed with single-leg KE (8.1 ± 1.2 min; 45 ± 4 W) resulted in significantly greater peripheral quadriceps fatigue than double-leg KE (10 ± 1.3 min; 83 ± 7 W), as documented by changes in the iEMG signal (147 ± 24 vs. 85 ± 13%), MVC (−25 ± 3 vs. −12 ± 3%), and Qtw,pot (−44 ± 6 vs. −33 ± 7%), for single-leg and double-leg KE, respectively. Therefore, avoiding concerns over task specificity and cardiorespiratory limitations, this study reveals that a reduction in muscle mass permits the development of greater peripheral muscle fatigue and supports the concept that the CNS tolerates a greater magnitude of peripheral fatigue when the source of group III/IV afferent feedback is limited to a small muscle mass.

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Between-muscle differences in the adaptation to experimental pain

Journal of Applied Physiology ◽

10.1152/japplphysiol.00561.2014 ◽

2014 ◽

Vol 117 (10) ◽

pp. 1132-1140 ◽

Cited By ~ 16

Author(s):

François Hug ◽

Paul W. Hodges ◽

Wolbert van den Hoorn ◽

Kylie Tucker

Keyword(s):

Elastic Modulus ◽

Vastus Lateralis ◽

Experimental Pain ◽

Rectus Femoris ◽

Quadriceps Muscle ◽

Knee Extension ◽

Shear Elastic Modulus ◽

Emg Amplitude ◽

Extension Force ◽

Muscle Stress

This study aimed to determine whether muscle stress (force per unit area) can be redistributed between individual heads of the quadriceps muscle when pain is induced into one of these heads. Elastography was used to measure muscle shear elastic modulus (an index of muscle stress). Electromyography (EMG) was recorded from vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF). In experiment I ( n = 20), participants matched a knee extension force, and thus any reduction of stress within the painful muscle would require compensation by other muscles. In experiment II ( n = 13), participants matched VL EMG amplitude and were free to vary external force such that intermuscle compensation would be unnecessary to maintain the experimental task. In experiments I and II, pain was induced by injection of hypertonic saline into VM or RF. Experiment III aimed to establish whether voluntary drive to the individual muscles could be controlled independently. Participants ( n = 13) were asked to voluntarily reduce activation of VM or RF while maintaining knee extension force. During VM pain, there was no change in shear elastic modulus ( experiments I and II) or EMG amplitude of VM ( experiment II). In contrast, RF pain was associated with a reduction in RF elastic modulus ( experiments I and II: −8 to −17%) and EMG amplitude ( experiment II). Participants could voluntarily reduce EMG amplitude of RF ( −26%; P = 0.003 ) but not VM ( experiment III). These results highlight between-muscle differences in adaptation to pain that might be explained by their function (monoarticular vs. biarticular) and/or the neurophysiological constraints associated to their activation.

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Shear elastic modulus can be used to estimate an index of individual muscle force during a submaximal isometric fatiguing contraction

Journal of Applied Physiology ◽

10.1152/japplphysiol.00858.2012 ◽

2012 ◽

Vol 113 (9) ◽

pp. 1353-1361 ◽

Cited By ~ 56

Author(s):

Killian Bouillard ◽

François Hug ◽

Arnaud Guével ◽

Antoine Nordez

Keyword(s):

Elastic Modulus ◽

Muscle Force ◽

Vastus Lateralis ◽

Rectus Femoris ◽

Load Sharing ◽

Knee Extension ◽

Voluntary Contraction ◽

Activity Level ◽

Shear Elastic Modulus ◽

Individual Muscle

The present study was designed to determine whether fatigue alters the ability to estimate an index of individual muscle force from shear elastic modulus measurements ( experiment I), and to test the ability of this technique to highlight changes in load sharing within a redundant muscle group during an isometric fatiguing task ( experiment II). Twelve subjects participated in experiment I, which consisted of smooth linear torque ramps from 0 to 80% of maximal voluntary contraction (MVC) performed before and after an isometric fatigue protocol, beginning at 40% of MVC and stopped when the force production dropped below 30% of MVC. Although the relationships between modulus and torque were very similar for pre- and postfatigue [root mean square deviation (RMSdeviation) = 3.7 ± 2.6% of MVC], the relationships between electromyography activity level and torque were greatly altered by fatigue (RMSdeviation = 10.3 ± 2.6% of MVC). During the fatiguing contraction, shear elastic modulus provided a significantly lower RMSdeviation between measured torque and estimated torque than electromyography activity level (5.7 ± 0.9 vs. 15.3 ± 3.8% of MVC). Experiment II performed with eight participants consisted of an isometric knee extension at 25% of MVC sustained until exhaustion. Opposite changes in shear elastic modulus were observed between synergists (vastus medialis, vastus lateralis, and rectus femoris) of some participants, reflecting changes in load sharing. In conclusion, despite the fact that we did not directly estimate muscle force (in Newtons), this is the first demonstration of an experimental technique to accurately quantify relative changes in force in an individual human muscle during a fatiguing contraction.

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Task dependency of motor adaptations to an acute noxious stimulation

Journal of Neurophysiology ◽

10.1152/jn.00911.2013 ◽

2014 ◽

Vol 111 (11) ◽

pp. 2298-2306 ◽

Cited By ~ 17

Author(s):

François Hug ◽

Paul W. Hodges ◽

Kylie Tucker

Keyword(s):

Elastic Modulus ◽

Degrees Of Freedom ◽

Isometric Force ◽

Vastus Lateralis ◽

Knee Extension ◽

Noxious Stimulation ◽

Shear Elastic Modulus ◽

Emg Amplitude ◽

Single Leg Squat ◽

Control Pain

This study explored motor adaptations in response to an acute noxious stimulation during three tasks that differed in the number of available degrees of freedom. Fifteen participants performed three isometric force-matched tasks (single leg knee extension, single leg squat, and bilateral leg squat) in three conditions (Control, Pain, and Washout). Pain was induced by injection of hypertonic saline into the vastus medialis muscle (VM; left leg). Supersonic shear imaging was used to measure muscle shear elastic modulus as this is considered to be an index of muscle stress. Surface electromyography (EMG) was recorded bilaterally from six muscles to assess changes in neural strategies. During tasks with fewer degrees of freedom (knee extension and single leg squat task), there was no change in VM EMG amplitude or VM shear elastic modulus. In contrast, during the bilateral leg squat, VM (−32.9 ± 15.8%; P < 0.001) and vastus lateralis (−28.7 ± 14.8%; P < 0.001) EMG amplitude decreased during Pain. This decrease in activation was associated with reduced VM shear elastic modulus (−17.6 ± 23.3%; P = 0.029) and reduced force produced by the painful leg (−10.0 ± 10.2%; P = 0.046). This work provides evidence that when an obvious solution is available to decrease stress on painful tissue, this option is selected. It confirms the fundamental assumption that motor adaptations to pain aim to alter load on painful tissue to protect for further pain and/or injury. The lack of adaptation observed during force-matched tasks with fewer degrees of freedom might be explained by the limited potential to redistribute stress or a high cost induced by such a compensation.

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Prevalence of the additional head of quadriceps femoris in the South Indian population: a cadaveric and radiological study

Scientific Reports ◽

10.1038/s41598-021-95374-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Femina Sam ◽

Madhavi Kandagaddala ◽

Ivan James Prithishkumar ◽

Koyeli Mary Mahata ◽

Mahasampath Gowri ◽

...

Keyword(s):

Indian Population ◽

Vastus Lateralis ◽

Femoral Nerve ◽

Quadriceps Femoris ◽

Lower Limbs ◽

South Indian Population ◽

The South ◽

South Indian ◽

Circumflex Femoral Artery ◽

Vastus Intermedius

AbstractQuadriceps femoris is an extensor muscle in the anterior compartment of thigh and is traditionally taught to be composed of four heads. Recently, there is an increased interest in the occurrence of an additional muscle head of quadriceps femoris. But scientific knowledge regarding its incidence is lacking in the South Indian population. This study was done to confirm the presence of the additional head by routine anatomic dissection and radiological imaging techniques. Forty-one formalin fixed human cadaveric lower limbs were dissected and the morphology of the additional head was noted. Retrospective analysis of 88 MRI images of patients was done. The additional muscle head was present in 43.9% of the cadaveric lower limbs and was consistently located between the vastus lateralis and vastus intermedius. It originated from variable portions of the greater trochanter, intertrochanteric line, lateral lip of linea aspera and lateral surface of the shaft of femur and inserted either as a muscle belly or as an aponeurosis into the vastus intermedius (55.6%), vastus lateralis (22.2%) or directly into the base of the patella. It received its vascular supply from branches of the lateral circumflex femoral artery and was innervated by branches from the posterior division of the femoral nerve. In addition, the additional muscle head was identified by MRI and its incidence was reported to be 30.68% for the first time in living subjects. The result of this study provides additional information in understanding the morphology of the quadriceps femoris muscle.

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Effect of Static Stretching with Superficial Cooling on Muscle Stiffness

Sports Medicine International Open ◽

10.1055/a-0684-9375 ◽

2018 ◽

Vol 02 (05) ◽

pp. E142-E147 ◽

Cited By ~ 2

Author(s):

Masatoshi Nakamura ◽

Ryo Hirabayashi ◽

Shuhei Ohya ◽

Takafumi Aoki ◽

Daichi Suzuki ◽

...

Keyword(s):

Elastic Modulus ◽

Random Order ◽

Acute Effect ◽

Muscle Stiffness ◽

Cooling Condition ◽

Medial Gastrocnemius ◽

Static Stretching ◽

Shear Elastic Modulus ◽

And Control ◽

Healthy Males

AbstractThis study aimed to clarify the acute effect of static stretching (SS) with superficial cooling on dorsiflexion range of motion (DF ROM) and muscle stiffness. Sixteen healthy males participated in the cooling condition and a control condition in a random order. The DF ROM and the shear elastic modulus of medial gastrocnemius (MG) in the dominant leg were measured during passive dorsiflexion. All measurements were performed prior to (PRE) and immediately after 20 min of cooling or rested for 20 min (POST), followed by 2 min SS (POST SS). In cooling condition, DF ROM at POST and POST SS were significantly higher than that at PRE and DF ROM at POST SS was significantly higher than that at POST. In addition, the shear elastic modulus at POST was significantly higher than that at PRE and the shear elastic modulus at POST SS was significantly lower than those at PRE and POST. However, there were no significant differences in the percentage changes between PRE and POST SS between the cooling and control conditions. Our results showed that effects of SS with superficial cooling on increases in ROM and decrease in muscle stiffness were no more beneficial than those of SS alone.

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