scholarly journals Dynamics of Quadriceps Muscles during Isometric Contractions: Velocity-Encoded Phase Contrast MRI Study

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2280
Author(s):  
Toshiaki Oda ◽  
Vadim Malis ◽  
Taija Finni ◽  
Ryuta Kinugasa ◽  
Shantanu Sinha
Keyword(s):  
Phase Contrast ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Voluntary Contraction ◽  
Ensemble Average ◽  
The Other ◽  
Phase Contrast Mri ◽  
Axial Section ◽  
Measured Velocity ◽  
Thigh Muscles

Objective: To quantify the spatial heterogeneity of displacement during voluntary isometric contraction within and between the different compartments of the quadriceps. Methods: The thigh muscles of seven subjects were imaged on an MRI scanner while performing isometric knee extensions at 40% maximal voluntary contraction. A gated velocity-encoded phase contrast MRI sequence in axial orientations yielded tissue velocity-encoded dynamic images of the four different compartments of the thigh muscles (vastus lateralis (VL), vastus medialis (VM), vastus intermedius (VI), and rectus femoris (RF)) at three longitudinal locations of the proximal–distal length: 17.5% (proximal), 50% (middle), and 77.5% (distal). The displacement, which is the time integration of the measured velocity, was calculated along the three orthogonal axes using a tracking algorithm. Results: The displacement of the muscle tissues was clearly nonuniform within each axial section as well as between the three axial locations. The ensemble average of the magnitude of the total displacement as a synthetic vector of the X, Y, and Z displacements was significantly larger in the VM at the middle location (p < 0.01), and in the VI at the distal location than in the other three muscles. The ensemble average of Z-axis displacement, which was almost aligned with the line of action, was significantly larger in VI than in the other three muscles in all three locations. Displacements of more than 20 mm were observed around the central aponeuroses, such as those between VI and the other surrounding muscles. Conclusions: These results imply that the quadriceps muscles act as one functional unit in normal force generation through the central aponeuroses despite complex behavior in each of the muscles, each of which possesses different physiological characteristics and architectures.

Alternate muscle activity observed between knee extensor synergists during low-level sustained contractions

2002 ◽  
Vol 93 (2) ◽  
pp. 675-684 ◽  
Author(s):  
Motoki Kouzaki ◽  
Minoru Shinohara ◽  
Kei Masani ◽  
Hiroaki Kanehisa ◽  
Tetsuo Fukunaga
Keyword(s):  
Muscle Activity ◽  
Vastus Lateralis ◽  
Force Production ◽  
Knee Extensor ◽  
Rectus Femoris ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Low Level ◽  
Integrated Emg

To determine quantitatively the features of alternate muscle activity between knee extensor synergists during low-level prolonged contraction, a surface electromyogram (EMG) was recorded from the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) in 11 subjects during isometric knee extension exercise at 2.5% of maximal voluntary contraction (MVC) for 60 min ( experiment 1). Furthermore, to examine the relation between alternate muscle activity and contraction levels, six of the subjects also performed sustained knee extension at 5.0, 7.5, and 10.0% of MVC ( experiment 2). Alternate muscle activity among the three muscles was assessed by quantitative analysis on the basis of the rate of integrated EMG sequences. In experiment 1, the number of alternations was significantly higher between RF and either VL or VM than between VL and VM. Moreover, the frequency of alternate muscle activity increased with time. In experiment 2, alternating muscle activity was found during contractions at 2.5 and 5.0% of MVC, although not at 7.5 and 10.0% of MVC, and the number of alternations was higher at 2.5 than at 5.0% of MVC. Thus the findings of the present study demonstrated that alternate muscle activity in the quadriceps muscle 1) appears only between biarticular RF muscle and monoarticular vasti muscles (VL and VM), and its frequency of alternations progressively increases with time, and 2) emerges under sustained contraction with force production levels ≤5.0% of MVC.

The frequency of alternate muscle activity is associated with the attenuation in muscle fatigue

2006 ◽  
Vol 101 (3) ◽  
pp. 715-720 ◽  
Author(s):  
Motoki Kouzaki ◽  
Minoru Shinohara
Keyword(s):  
Muscle Fatigue ◽  
Muscle Activity ◽  
Healthy Subjects ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Sustained Contraction ◽  
Low Level ◽  
Before And After

Alternate muscle activity between synergist muscles has been demonstrated during low-level sustained contractions [≤5% of maximal voluntary contraction (MVC) force]. To determine the functional significance of the alternate muscle activity, the association between the frequency of alternate muscle activity during a low-level sustained knee extension and the reduction in knee extension MVC force was studied. Forty-one healthy subjects performed a sustained knee extension at 2.5% MVC force for 1 h. Before and after the sustained knee extension, MVC force was measured. The surface electromyogram was recorded from the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles. The frequency of alternate muscle activity for RF-VL, RF-VM, and VL-VM pairs was determined during the sustained contraction. The frequency of alternate muscle activity ranged from 4 to 11 times/h for RF-VL (7.0 ± 2.0 times/h) and RF-VM (7.0 ± 1.9 times/h) pairs, but it was only 0 to 2 times/h for the VL-VM pair (0.5 ± 0.7 times/h). MVC force after the sustained contraction decreased by 14% ( P < 0.01) from 573.6 ± 145.2 N to 483.3 ± 130.5 N. The amount of reduction in MVC force was negatively correlated with the frequency of alternate muscle activity for the RF-VL and RF-VM pairs ( P < 0.001 and r = 0.65 for both) but not for the VL-VM pair. The results demonstrate that subjects with more frequent alternate muscle activity experience less muscle fatigue. We conclude that the alternate muscle activity between synergist muscles attenuates muscle fatigue.

Decrease in maximal voluntary contraction by tonic vibration applied to a single synergist muscle in humans

2000 ◽  
Vol 89 (4) ◽  
pp. 1420-1424 ◽  
Author(s):  
Motoki Kouzaki ◽  
Minoru Shinohara ◽  
Tetsuo Fukunaga
Keyword(s):  
Maximal Voluntary Contraction ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Vastus Medialis ◽  
Force Development ◽  
Ia Afferent ◽  
Before And After ◽  
Integrated Emg

The purpose of the study was to examine the effect of prolonged tonic vibration applied to a single synergist muscle on maximal voluntary contraction (MVC) and maximal rate of force development (dF/d t max). The knee extension MVC force and surface electromyogram (EMG) from the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) during MVC were recorded before and after vibration of RF muscle at 30 Hz for 30 min. MVC, dF/d t max, and the integrated EMG (iEMG) of RF decreased significantly after prolonged tonic vibration in spite of no changes in iEMG of VL and VM. The present results indicate that MVC and dF/d t max may be influenced by the attenuated Ia afferent functions of a single synergist muscle.

scholarly journals The Relationship Between Additional Heads of the Quadriceps Femoris, the Vasti Muscles and the Patellar Ligament

2021 ◽  
Author(s):  
Łukasz Olewnik ◽  
Kacper Ruzik ◽  
Bartłomiej Szewczyk ◽  
Michał Podgórski ◽  
Paloma Aragonés ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Quadriceps Femoris ◽  
The Other ◽  
Lower Limbs ◽  
Patellar Ligament ◽  
Vastus Medialis ◽  
Vastus Intermedius ◽  
Deep Layers ◽  
The Relationship

Abstract Introduction: The quadriceps femoris consists of four muscles: the rectus femoris, vastus medialis, vastus intermedius and vastus lateralis. However, the effect of additional quadriceps femoris heads on the vasti muscles and patellar ligaments is unknown.Materials and Methods: One hundred and six lower limbs (34 male and 19 female cadavers) fixed in 10% formalin were examined.Results: On all lower extremities, the vastus lateralis consisted of superficial, intermediate and deep layers. The vastus medialis, on the other hand, consisted of only the longus and obliquus layers. Additional quadriceps femoris heads affected both the vasti muscles and the patellar ligaments.Conclusion: There is a strong correlation between the presence of accessory quadriceps femoris heads and effects on vasti muscles and patellar ligament.

Cat hindlimb motoneurons during locomotion. II. Normal activity patterns

1987 ◽  
Vol 57 (2) ◽  
pp. 530-553 ◽  
Author(s):  
J. A. Hoffer ◽  
N. Sugano ◽  
G. E. Loeb ◽  
W. B. Marks ◽  
M. J. O'Donovan ◽  
...  
Keyword(s):  
Firing Rate ◽  
Vastus Lateralis ◽  
Activity Patterns ◽  
Rectus Femoris ◽  
Emg Activity ◽  
Step Cycle ◽  
Firing Rates ◽  
Anterior Thigh ◽  
Thigh Muscles ◽  
Walking Speeds

Activity patterns were recorded from 51 motoneurons in the fifth lumbar ventral root of cats walking on a motorized treadmill at a range of speeds between 0.1 and 1.3 m/s. The muscle of destination of recorded motoneurons was identified by spike-triggered averaging of EMG recordings from each of the anterior thigh muscles. Forty-three motoneurons projected to one of the quadriceps (vastus medialis, vastus lateralis, vastus intermedius, or rectus femoris) or sartorius (anterior or medial) muscles of the anterior thigh. Anterior thigh motoneurons always discharged a single burst of action potentials per step cycle, even in multifunctional muscles (e.g., sartorius anterior) that exhibited more than one burst of EMG activity per step cycle. The instantaneous firing rates of most motoneurons were lowest upon recruitment and increased progressively during a burst, as long as the EMG was still increasing. Firing rates peaked midway through each burst and tended to decline toward the end of the burst. The initial, mean, and peak firing rates of single motoneurons typically increased for faster walking speeds. At any given walking speed, early recruited motoneurons typically reached higher firing rates than late recruited motoneurons. In contrast to decerebrated cats, initial doublets at the beginning of bursts were seen only rarely. In the 4/51 motoneurons that showed initial doublets, both the instantaneous frequency of the doublet and the probability of starting a burst with a doublet decreased for faster walking speeds. The modulations in firing rate of every motoneuron were found to be closely correlated to the smoothed electromyogram of its target muscle. For 32 identified motoneurons, the unit's instantaneous frequencygram was scaled linearly by computer to the rectified smoothed EMG recorded from each of the anterior thigh muscles. The covariance between unitary frequencygram and muscle EMG was computed for each muscle. Typically, the EMG profile of the target muscle accounted for 0.88-0.96 of the variance in unitary firing rate. The EMG profiles of the other anterior thigh muscles, when tested in the same way, usually accounted only for a significantly smaller fraction of the variance. Brief amplitude fluctuations observed in the EMG envelopes were usually also reflected in the individual motoneuron frequencygrams. To further demonstrate the relationship between unitary frequencygrams and EMG, EMG envelopes recorded during walking were used as templates to generate depolarizing currents that were applied intracellularly to lumbar motoneurons in an acute spinal preparation.(ABSTRACT TRUNCATED AT 400 WORDS)

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

2014 ◽  
Vol 111 (4) ◽  
pp. 768-776 ◽  
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.

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

2012 ◽  
Vol 113 (9) ◽  
pp. 1353-1361 ◽  
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.

Vastus lateralis fatigue alters recruitment of musculus quadriceps femoris in humans

2002 ◽  
Vol 92 (2) ◽  
pp. 679-684 ◽  
Author(s):  
Hiroshi Akima ◽  
Jeanne M. Foley ◽  
Barry M. Prior ◽  
Gary A. Dudley ◽  
Ronald A. Meyer
Keyword(s):  
Vastus Lateralis ◽  
Transverse Relaxation Time ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Magnetic Resonance Images ◽  
Quadriceps Femoris ◽  
The Other ◽  
Musculus Quadriceps Femoris ◽  
Musculus Quadriceps ◽  
Before And After

This study tested the hypothesis that fatigue of a single member of musculus quadriceps femoris (QF) would alter use of the other three muscles during knee extension exercise (KEE). Six men performed KEE with the left QF at a load equal to 50% of the 4 × 10 repetitions maximum. Subsequently, electromyostimulation (EMS), intended to stimulate and fatigue the left m. vastus lateralis (VL), was applied for 30 min. Immediately after EMS, subjects repeated the KEE. Transverse relaxation time (T2)-weighted magnetic resonance images were taken before and after each bout of KEE and at 3 and 30 min of EMS to assess use and stimulation, respectively, of the QF. T2 of each of the QF muscles was increased 8–13% after the first KEE. During EMS, T2 increased ( P < 0.05) even more in VL (10%), whereas it decreased ( P < 0.05) to pre-KEE levels in m. vastus medials (VM) and m. rectus femoris (RF). The VL and, to some extent, the m. vastus intermedius were stimulated, whereas the VM and RF were not, thereby recovering from the first bout of KEE. Isometric torque, initially 30% of maximal voluntary, was reduced to 13% at 3 min and 7% at 30 min. T2 was greater ( P < 0.05) after the second than the first bout of KEE, especially the increase for the VM and RF. These results suggest that subjects were able to perform the second bout with little contribution of the VL by greater use of the other QF muscles. The simplest explanation is increased central command to the QF such that the intended act could be accomplished despite acute fatigue of one of its synergists.

Less common synaptic input between muscles from the same group allows for more flexible coordination strategies during a fatiguing task

2022 ◽  
Author(s):  
Julien Rossato ◽  
Kylie J. Tucker ◽  
Simon Avrillon ◽  
Lilian Lacourpaille ◽  
Ales Holobar ◽  
...  
Keyword(s):  
Synaptic Input ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Motor Units ◽  
The Other ◽  
Triceps Surae ◽  
Strong Positive Correlation ◽  
Neural Drive ◽  
Coordination Strategies ◽  
Common Drive

This study aimed to determine whether neural drive is redistributed between muscles during a fatiguing isometric contraction, and if so, whether the initial level of common synaptic input between these muscles constrains this redistribution. We studied two muscle groups: triceps surae (14 participants) and quadriceps (15 participants). Participants performed a series of submaximal isometric contractions and a torque-matched contraction maintained until task failure. We used high-density surface electromyography to identify the behavior of 1874 motor units from the soleus, gastrocnemius medialis (GM), gastrocnemius lateralis(GL), rectus femoris, vastus lateralis (VL), and vastus medialis(VM). We assessed the level of common drive between muscles in absence of fatigue using a coherence analysis. We also assessed the redistribution of neural drive between muscles during the fatiguing contraction through the correlation between their cumulative spike trains (index of neural drive). The level of common drive between VL and VM was significantly higher than that observed for the other muscle pairs, including GL-GM. The level of common drive increased during the fatiguing contraction, but the differences between muscle pairs persisted. We also observed a strong positive correlation of neural drive between VL and VM during the fatiguing contraction (r=0.82). This was not observed for the other muscle pairs, including GL-GM, which exhibited differential changes in neural drive. These results suggest that less common synaptic input between muscles allows for more flexible coordination strategies during a fatiguing task, i.e., differential changes in neural drive across muscles. The role of this flexibility on performance remains to be elucidated.

scholarly journals Co-contraction training: myoelectric activity and recruitment strategies in an unorthodox resistance training technique.

2021 ◽  
Author(s):  
Nilson Ribeiro dos Santos Silva ◽  
Matheus Pacheco ◽  
Rafael Akira Fujita ◽  
Marina Mello Villalba ◽  
MATHEUS MACHADO GOMES
Keyword(s):  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Voluntary Contraction ◽  
Lower Limbs ◽  
Emg Activity ◽  
Myoelectric Activity ◽  
Muscle Recruitment ◽  
Recruitment Pattern ◽  
Recruitment Patterns

Objective To elucidate the muscle recruitment patterns and interindividual variability during co-contraction training sessions for lower limbs. Methods Ten active male young adults underwent two days of tests, in which they performed, for each leg, a maximal isometric voluntary contraction protocol followed by a co-contraction training set. We acquired myoelectric (EMG) activity from the sartorius, biceps femoris long and short heads, semitendinosus, semimembranosus, rectus femoris, vastus lateralis and vastus medialis and tensor facia latae during both protocols. We used iterative HLM analyses and bootstrap ANOVAs to explain within and between participant variances. Results On average, participants started recruiting 36% of their maximum EMG amplitude, showing decays of 0.41% per repetition and increasing 7.45% from day 1 to day 2. Participants who started with higher recruitment showed greater decays over repetitions and vice-versa. The training stimulated similarly the ratio of participants’ flexors and extensors. However, participants demonstrated different average muscle recruitment patterns with some individuals modifying, largely, their recruitment over repetitions/days. Between and within-variability in recruitment pattern was maintained throughout repetitions and days. We found no consistent similarity in terms of pairs of participants as to find common types of recruitment. Conclusion Co-contraction training seems to be effective to recruit thigh muscles of both legs along an entire set of repetitions and days. Despite the accounted variations in intramuscular recruitment, co-contraction training evokes similar muscular in flexor’s and extensor’s recruitment among participants.

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