scholarly journals Neural and morphological adaptations of vastus lateralis and vastus medialis muscles to isokinetic eccentric training

2014 ◽  
Vol 20 (3) ◽  
pp. 317-324 ◽  
Author(s):  
Rodrigo de Azevedo Franke ◽  
Bruno Manfredini Baroni ◽  
Rodrigo Rodrigues ◽  
Jeam Marcel Geremia ◽  
Fábio Juner Lanferdini ◽  
...  
Keyword(s):  
Training Program ◽  
Vastus Lateralis ◽  
Control Period ◽  
Muscle Thickness ◽  
Knee Extension ◽  
Vastus Medialis ◽  
Eccentric Training ◽  
Rehabilitation Programs ◽  
Morphological Adaptations ◽  
Synergistic Muscles

Vastus lateralis (VL) and vastus medialis (VM) are frequently targeted in conditioning/rehabilitation programs due to their role in patellar stabilization during knee extension. This study assessed neural and muscular adaptations in these two muscles after an isokinetic eccentric training program. Twenty healthy men underwent a four-week control period followed by a 12-week period of isokinetic eccentric training. Ultrasound evaluations of VL and VM muscle thickness at rest and electromyographic evaluations during maximal isometric tests were used to assess the morphological and neural properties, respectively. No morphological and neural changes were found throughout the control period, whereas both muscles showed significant increases in thickness (VL = 6.9%; p < .001 and VM = 15.8%; p < .001) post-training. Significant increases in muscle activity were observed in VM (47.8%; p = .003), but not in VL (19.8%; p > .05) post-training. Isokinetic eccentric training produces neural and greater morphological adaptations in VM compared to VL, which shows that synergistic muscles respond differently to an eccentric isokinetic strength training program

scholarly journals Exploratory study of electromyographic behavior of the vastus medialis and vastus lateralis at neuromuscular fatigue onset

2014 ◽  
Vol 20 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Cristiano Rocha da Silva ◽  
Danilo de Oliveira Silva ◽  
Deisi Ferrari ◽  
Rúben de Faria Negrão Filho ◽  
Neri Alves ◽  
...  
Keyword(s):  
Exploratory Study ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Neuromuscular Fatigue ◽  
Isometric Contractions ◽  
Median Frequency ◽  
Vastus Medialis ◽  
Mean Square ◽  
Electromyographic Signal ◽  
The Moment

This study aimed to determine and analyze the neuromuscular fatigue onset by median frequency (MDF) and the root mean square (RMS) behavior of an electromyographic signal (EMG). Eighteen healthy men with no prior knee problems initially performed three maximum voluntary isometric contractions (MVIC). After two days of MVIC test, participants performed a fatiguing protocol in which they performed submaximal knee-extension contractions at 20% and 70% MVIC held to exhaustion. The MDF and RMS values from the EMG signals were recorded from the vastus medialis (VM) and the vastus lateralis (VL). Analysis of the MDF and RMS behavior enabled identification of neuromuscular fatigue onset for VM and VL muscles in 20% and 70% loads. Alterations between the VM and VL in the neuromuscular fatigue onset, at 20% and 70% MVIC, were not significant. These findings suggest that the methodology proposal was capable of indicating minute differences sensible to alterations in the EMG signals, allowing identification of the moment when the MDF and the RMS showed significant changes in behavior. The methodology used was also a viable one for describing and identifying the neuromuscular fatigue onset by means of the analysis of EMG signals.

Can Hip Joint Position affect Quadriceps Muscle Responses during Knee Extension Exercise?

2020 ◽  
Vol 41 (13) ◽  
pp. 929-935
Author(s):  
Denis César Leite Vieira ◽  
Marco Aurélio Araujo Dourado ◽  
Lucas Ugliara ◽  
Joao Luiz Quagliotti Durigan ◽  
Brad J. Schoenfeld ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Muscle Thickness ◽  
Rectus Femoris ◽  
Peak Torque ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Knee Extensors ◽  
Work Output ◽  
Before And After ◽  
Knee Extension Exercise

AbstractThis study investigated the acute effects of seated and supine knee extension exercise on muscle swelling, torque, and work output. Twelve resistance-trained men performed two isokinetic concentric-only knee-extension training protocols at different hip positions in a counter-balanced order. They completed the knee extension exercise in the seated (hip angle at 85°) and supine (hip angle at 180°) positions. The torque and work output were assessed during each set. Moreover, muscle thickness of the middle and proximal vastus lateralis and rectus femoris were evaluated before and after each protocol and used as an indicator of muscle swelling. Middle rectus femoris and proximal vastus lateralis thickness increased significantly (p=0.01) with no difference between exercise variations. However, the middle vastus lateralis thickness increased (p=0.01) only after the seated knee extension exercise (~7%). Knee extensors’ peak torque and work output were approximately 8% higher (p=0.04) in the seated when compared to the supine hip position. There was a similar decrease in torque and work output throughout both protocols (p=0.98). In conclusion, seated knee extension exercises produced greater torque, work output, and muscle swelling in the vastus lateralis when compared to the supine knee extension exercise.

Motor units in vastus lateralis and in different vastus medialis regions show different firing properties during low-level, isometric knee extension contraction

2018 ◽  
Vol 58 ◽  
pp. 307-314 ◽  
Author(s):  
Leonardo Mendes Leal de Souza ◽  
Hélio Veiga Cabral ◽  
Liliam Fernandes de Oliveira ◽  
Taian Martins Vieira
Keyword(s):  
Vastus Lateralis ◽  
Motor Units ◽  
Knee Extension ◽  
Vastus Medialis ◽  
Low Level ◽  
Isometric Knee Extension ◽  
Firing Properties

Examining Neuromuscular Control of the Vastus Medialis Oblique and Vastus Lateralis Muscles During Fundamental Dance Movements

2020 ◽  
Vol 24 (4) ◽  
pp. 153-160
Author(s):  
Hannah Weighart ◽  
Noelle Morrow ◽  
Sarah DiPasquale ◽  
Stephen J. Ives
Keyword(s):  
External Rotation ◽  
Vastus Lateralis ◽  
Neuromuscular Control ◽  
Surface Emg ◽  
Knee Extension ◽  
Vastus Medialis ◽  
Important Indicator ◽  
Significant Relationships ◽  
Dance Movements ◽  
Patellofemoral Alignment

Elite dancers have a higher rate of injury than college athletes. This may be due, in part, to improper alignment during dance movements. Electromyography (EMG) can be an important indicator of such activity. This study aimed to examine how turnout (maximal hip external rotation) impacts activation of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles during fundamental dance movements. Thirty female collegiate dancers were recruited from intermediate and advanced ballet and modern technique classes. Surface EMG was used to examine activation of the VMO and VL during maximal isokinetic knee extension in demi-pliés and sautés in parallel and turned-out positions. The mean VMO:VL ratio was determined as a percentage of the highest repetition of maximal extension. The ratio was significantly lower during parallel sautés (0.921 ± 0.258) in comparison to turned-out sautés (1.008 ± 0.384; p = 0.033) and parallel pliés (1.185 ± 0.509; p = 0.002). No significant relationships were found between the VMO:VL ratio and injury history or predominant style of dance. Further investigation is warranted to examine the relationships between VMO:VL activation, patellofemoral alignment, and risk of pathology during simple and complex dance movements.

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.

Vastus Lateralis and Vastus Medialis Obliquus Activity during a Straight-Leg Raise and Knee Extension with Lateral Hip Rotation

2002 ◽  
Vol 11 (2) ◽  
pp. 120-126 ◽  
Author(s):  
Nicole M. Livecchi ◽  
Charles W. Armstrong ◽  
Mitchell L. Cordova ◽  
Mark A. Merrick ◽  
James M. Rankin
Keyword(s):  
Repeated Measures ◽  
Outcome Measure ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Emg Activity ◽  
Neutral Position ◽  
Vastus Medialis ◽  
Vastus Medialis Obliquus ◽  
Main Outcome Measure ◽  
Straight Leg Raise

Objective:To compare average electromyogram (EMG) activity of the vastus medialis obliquus (VMO) and vastus lateralis (VL) during straight-leg raise (SLR) and knee extension (KE) with the hip in neutral and lateral rotation.Design:1 × 4 factorial repeated-measures.Setting:Laboratory.Participants:13 male college students.Intervention:SLR with hip flexed at 40°, in neutral position, and maximally laterally rotated and KE with hip in neutral and maximally laterally rotated.Main Outcome Measure:Average EMG activity during each of the 4 conditions, normalized against peak muscle activity during that trial.Results:No differences were observed between exercises in VMO activity (F3,36= 0.646,P> .05), VL activity (F3,36= 1.08,P> .05), or VMO:VL ratio (F3,36= 0.598,P> .05).Conclusions:Electrical activity of the VMO or VL and VMO:VL ratio do not change with hip position or exercise.

scholarly journals Relationship between upper and lower limbs muscle explosive strength with the vastus lateralis and biceps brachii architecture

2021 ◽  
Vol 43 ◽  
Author(s):  
Conrado Laett ◽  
Ubiratã Gavilão ◽  
Jéssica do Rio ◽  
Victor Cossich ◽  
Carlos Gomes de Oliveira
Keyword(s):  
Biceps Brachii ◽  
Vastus Lateralis ◽  
Muscle Thickness ◽  
Elbow Flexion ◽  
Knee Extension ◽  
Muscle Architecture ◽  
Lower Limbs ◽  
Maximum Torque ◽  
Explosive Strength ◽  
Torque Development

ABSTRACT We aimed to assess upper and lower limbs explosive strength, and its correlation with biceps brachii (BB) and vastus lateralis (VL) architecture. Absolute and maximum torque normalized rate of torque development (RTD) were measured from isometric elbow flexion (EF) and knee extension (KE). BB and VL architectures were assessed by ultrasound. Absolute RTD of KE was higher (129–272%), although normalized RTD was higher in EF (80-21%). The absolute RTD was correlated to muscle thickness only in the BB (r=.39-46). No relationship was found between muscle architecture and normalized RTD. In conclusion, the higher RTD from KE seems to be due to their greater strength. Only the muscle architecture could not explain the differences found in the RTD.

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