scholarly journals Surface Electromyographic Validation of the Activity Ratio of the Vastus Medialis Oblique and Vastus Lateralis during Isokinetic Knee Extension

2019 ◽  
Vol 34 (6) ◽  
pp. 753-757
Author(s):  
Kiminobu FURUKAWA ◽  
Toshiya SHIMONO
Keyword(s):  
Activity Ratio ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Vastus Medialis

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.

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

Squat Muscle Activation Patterns with Hip Rotations in Subjects with Genu Varum Deformity

2020 ◽  
Author(s):  
Mohamadreza Hatefi ◽  
Farideh Babakhani ◽  
Ramin Balouchi ◽  
Amir Letafatkar ◽  
Brian J. Wallace
Keyword(s):  
Muscle Activation ◽  
Activity Ratio ◽  
External Rotation ◽  
Vastus Lateralis ◽  
Fascia Lata ◽  
Genu Varum ◽  
Vastus Medialis ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Hip Rotation

AbstractThe purpose of this study was to compare muscle activation during the squat with different hip rotations (neutral, 15, 30, and 45° of internal and external hip rotation) in subjects with and without Genu Varum deformity deformity. Surface electromyography were recorded from 32 men with (n=16) and without (n=16) Genu Varum deformity. In the Genu Varum deformity group, the squats with 30, 45 and 15° of internal rotations of the hip showed significantly greater gluteus medius activation as compared to other positions. Moreover, the tensor fascia lata activity increased with greater external rotation of the hip, and significantly more than hip internal rotations (p<0.05). For vastus medialis and vastus lateralis, both hip internal and external rotation showed a significantly greater activation compared to the neutral hip positions (p<0.05). There were significant differences in the gluteus medius:tensor fascia lata activity ratio (p=0.001) and the vastus medialis: vastus lateralis activity ratio (p=0.001) between the different hip positions in the Genu Varum deformity and healthy groups. These results demonstrate that muscle activation patterns varied significantly with the position of different hip rotation in both groups. Those with Genu Varum deformity may use this information to aid in an injury prevention strategy by choosing squat positioning that favorably alters muscle activation patterns.

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.

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

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.

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