scholarly journals Surface Electromyography Analysis of the Lower Extremities of Subjects Participating in Baduanjin Exercises

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Li Jin ◽  
Ran Li ◽  
Jing Chen ◽  
Qinbo Xue ◽  
Yueqin Yang
Keyword(s):  
Adverse Events ◽  
Physical Function ◽  
Surface Electromyography ◽  
Vastus Lateralis ◽  
Lower Extremities ◽  
Healthy Adults ◽  
Electromyographic Activity ◽  
Vastus Medialis ◽  
Mean Square ◽  
Integrated Electromyogram

Purpose. The purpose of this study was to assess the effects of practicing Baduanjin exercises on the lower extremities of subjects using electromyography analysis. Subjects. 110 healthy adults were randomly assigned as subjects to two groups: SG group who received sixteen weeks of Baduanjin training and CG group who received no training. Methods. The methods used in this study included the use of a sixteen-channel sEMG system to record and measure activity changes in vastus medialis and vastus lateralis. Results. After 16 weeks of Baduanjin training, the results of this study showed that the SG group had significant increases in RMS (root mean square) (in vastus lateralis, p > 0.05; in vastus medialis, p < 0.05), in AEMG (average electromyographic activity) (in vastus lateralis, p > 0.05; in vastus medialis, p < 0.05), and in IEMG (integrated electromyogram) (in vastus lateralis, p > 0.05; in vastus medialis, p < 0.05). No adverse events from treatment were reported during the whole period of this study. Conclusion. This study concludes that performing 16 weeks of Baduanjin training can significantly improve strength and the physical function of the lower extremities among healthy adults.

Reciprocal Coactivation Patterns of the Lateral and Medial Quadriceps and Hamstrings during Low- and Moderate-Speed Isokinetic Movement

1998 ◽  
Vol 7 (3) ◽  
pp. 182-196 ◽  
Author(s):  
Ronald V. Croce ◽  
John P. Miller ◽  
Robert Confessore ◽  
James C. Vailas
Keyword(s):  
Knee Joint ◽  
Female Athletes ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Median Frequency ◽  
Vastus Medialis ◽  
Mean Square ◽  
Joint Movement ◽  
Surface Electrodes ◽  
Emg Patterns

The purpose of this study was to examine coactivation patterns of the lateral and medial quadriceps and the lateral and medial hamstrings during low- and moderate-speed isokinetic movements. Twelve female athletes performed isokinetic knee assessments at 60 and 180°/s. Root mean square electromyographic (rmsEMG) activity and the median frequency of the EMG (mfEMG) were determined by placing bipolar surface electrodes on the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and medial hamstrings (MH). Results of rmsEMG indicated that the VM showed almost twice the coactivation of the VL (p< .05), and that the BF showed almost four times the coactivation of the MH (p <.05). Finally, differences were noted in the mfEMG (p< .05), with the VM displaying different recruitment patterns at 180°/s as an agonist compared to that as an antagonist. Results indicated that when acting as antagonists, the VM and BE display the greatest EMG patterns during isokinetic knee joint movement.

Alterations in Quadriceps Neurologic Complexity After Anterior Cruciate Ligament Reconstruction

2020 ◽  
pp. 1-6
Author(s):  
Steven M. Davi ◽  
Colleen K. Woxholdt ◽  
Justin L. Rush ◽  
Adam S. Lepley ◽  
Lindsey K. Lepley
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Ligament Reconstruction ◽  
Vastus Lateralis ◽  
Cruciate Ligament ◽  
Neuromuscular Control ◽  
Electromyographic Activity ◽  
Vastus Medialis ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

Context: Traditionally, quadriceps activation failure after anterior cruciate ligament reconstruction (ACLR) is estimated using discrete isometric torque values, providing only a snapshot of neuromuscular function. Sample entropy (SampEn) is a mathematical technique that can measure neurologic complexity during the entirety of contraction, elucidating qualities of neuromuscular control not previously captured. Objective: To apply SampEn analyses to quadriceps electromyographic activity in order to more comprehensively characterize neuromuscular deficits after ACLR. Design: Cross-sectional. Setting: Laboratory. Participants: ACLR: n = 18; controls: n = 24. Interventions: All participants underwent synchronized unilateral quadriceps isometric strength, activation, and electromyography testing during a superimposed electrical stimulus. Main Outcome Measures: Group differences in strength, activation, and SampEn were evaluated with t tests. Associations between SampEn and quadriceps function were evaluated with Pearson product–moment correlations and hierarchical linear regressions. Results: Vastus medialis SampEn was significantly reduced after ACLR compared with controls (P = .032). Vastus medialis and vastus lateralis SampEn predicted significant variance in activation after ACLR (r2 = .444; P = .003). Conclusions: Loss of neurologic complexity correlates with worse activation after ACLR, particularly in the vastus medialis. Electromyographic SampEn is capable of detecting underlying patterns of variability that are associated with the loss of complexity between key neurophysiologic events after ACLR.

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.

scholarly journals Effects of different vibration frequencies, amplitudes and contraction levels on lower limb muscles during graded isometric contractions superimposed on whole body vibration stimulation

2019 ◽  
Vol 6 ◽  
pp. 205566831982746 ◽  
Author(s):  
Amit N Pujari ◽  
Richard D Neilson ◽  
Marco Cardinale
Keyword(s):  
Isometric Contraction ◽  
Vastus Lateralis ◽  
Whole Body Vibration ◽  
Biceps Femoris ◽  
Whole Body ◽  
Isometric Contractions ◽  
Electromyographic Activity ◽  
Mean Square ◽  
Body Vibration ◽  
Neuromuscular Activity

Background Indirect vibration stimulation, i.e., whole body vibration or upper limb vibration, has been investigated increasingly as an exercise intervention for rehabilitation applications. However, there is a lack of evidence regarding the effects of graded isometric contractions superimposed on whole body vibration stimulation. Hence, the objective of this study was to quantify and analyse the effects of variations in the vibration parameters and contraction levels on the neuromuscular responses to isometric exercise superimposed on whole body vibration stimulation. Methods In this study, we assessed the ‘neuromuscular effects’ of graded isometric contractions, of 20%, 40%, 60%, 80% and 100% of maximum voluntary contraction, superimposed on whole body vibration stimulation (V) and control (C), i.e., no-vibration in 12 healthy volunteers. Vibration stimuli tested were 30 Hz and 50 Hz frequencies and 0.5 mm and 1.5 mm amplitude. Surface electromyographic activity of the vastus lateralis, vastus medialis and biceps femoris were measured during V and C conditions with electromyographic root mean square and electromyographic mean frequency values used to quantify muscle activity and their fatigue levels, respectively. Results Both the prime mover (vastus lateralis) and the antagonist (biceps femoris) displayed significantly higher (P < 0.05) electromyographic activity with the V than the C condition with varying percentage increases in EMG root-mean-square (EMGrms) values ranging from 20% to 200%. For both the vastus lateralis and biceps femoris, the increase in mean EMGrms values depended on the frequency, amplitude and muscle contraction level with 50 Hz–0.5 mm stimulation inducing the largest neuromuscular activity. Conclusions These results show that the isometric contraction superimposed on vibration stimulation leads to higher neuromuscular activity compared to isometric contraction alone in the lower limbs. The combination of the vibration frequency with the amplitude and the muscle tension together grades the final neuromuscular output.

scholarly journals The Residual Effect of Prior Drop Jumps on EMG Parameters of Thigh Muscles during Moderate and Heavy Cycling

2018 ◽  
Vol 2 (85) ◽  
Author(s):  
Neringa Baranauskienė ◽  
Loreta Stasiulė ◽  
Sandra Raubaitė ◽  
Arvydas Stasiulis
Keyword(s):  
Muscle Soreness ◽  
Vastus Lateralis ◽  
Residual Effect ◽  
Vastus Medialis ◽  
Mean Square ◽  
Cycling Exercise ◽  
Delayed Onset ◽  
Concentric Exercise ◽  
Thigh Muscles ◽  
Drop Jumps

Research  background  and  hypothesis.  Prior  eccentric  or  eccentric-concentric  exercise  induces  long  lasting muscle fatigue and delayed onset muscle soreness (DOMS). Moreover, the surface electromyograme sEMG amplitude increases under fatigue conditions. We suppose that prior eccentric – concentric exercise, inducing DOMS, increases EMG amplitude of thigh muscles during constant cycling exercises.Research aim of the study was to assess the residual effect of 100 prior drop jumps (PDJ) on the sEMG of m. vastus lateralis and m. vastus medialis during moderate and heavy intensity cycling exercises. Research methods. On four different days 10 female students performed one increasing and three (control, 45  min and 24 h after 100 drop jumps) moderate and heavy cycling (Ergoline-800, Germany) exercises. The cadence of cycling was 70 rpm. The sEMG of right thigh m. vastus lateralis and m. vastus medialis were continuously recorded during moderate and heavy cycling exercise. Creatine kinasis activity was measured and DOMS was rated 24 h after PDJ. Research results. After 24 h the subjects felt moderate DOMS (5.0 (2.79)) according to 10 point scale. The sEMG root mean square amplitude of m. vastus lateralis significantly increased 24 h after PDJ during moderate, but unaltered during heavy cycling exercise under fatigue conditions (45 min and 24 h after PDJ).Discussion and conclusion. Prior drop jumps seem to have significant residual (within 24 h of recovery) effect on EMG of thigh muscles during moderate cycling exercise in female students.Keywords: delayed onset muscle soreness, constant load, EMG root mean square.

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