scholarly journals Comparison of Inter- and Intra-Individual Neuromuscular Patterns of Responses During Moderate-Load Bilateral Leg Extension Exercise

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Taylor Dinyer-McNeely ◽  
Pasquale J. Succi ◽  
Caleb C. Voskuil ◽  
M. Travis Byrd ◽  
Haley C. Bergstrom
Keyword(s):  
Polynomial Regression ◽  
Vastus Lateralis ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Leg Extension ◽  
Linear Relationships ◽  
Left Limb ◽  
Neuromuscular Responses ◽  
Quadratic Relationship ◽  
The Right

Introduction: This study examined the electromyographic (EMG) and mechanomyographic (MMG), amplitude (AMP) and mean power frequency (MPF) responses during bilateral, leg extension exercise performed to failure at a moderate (70% one-repetition maximum [1RM]) load. Methods: Eleven men completed a 1RM and repetitions to failure at 70% 1RM of the leg extension. The EMG and MMG signals were recorded from the right and left vastus lateralis. Polynomial regression analyses were used to determine individual and composite, normalized neuromuscular responses for both limbs. Results: For EMG AMP, both limbs demonstrated positive, quadratic relationships. For EMG MPF, the right limb demonstrated a negative, cubic relationship and the left limb demonstrated a negative, quadratic relationship. For MMG AMP, the right limb demonstrated a positive, quadratic relationship and the left limb demonstrated a positive, linear relationship. For MMG MPF, both limbs demonstrated negative, linear relationships. 18-45% of the subjects demonstrated the same responses as the composite for the EMG and MMG signals. 14% of the subjects demonstrated the same direction and pattern of response for the right and left limb intra-individual responses. Conclusions: The variability in the inter- and intra-individual responses highlight the necessity to report individual neuromuscular responses when examining fatiguing resistance exercise.

scholarly journals Inter- and Intra-Individual Differences in EMG and MMG during Maximal, Bilateral, Dynamic Leg Extensions

Sports ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 175 ◽  
Author(s):  
John Paul V. Anders ◽  
Cory M. Smith ◽  
Joshua L. Keller ◽  
Ethan C. Hill ◽  
Terry J. Housh ◽  
...  
Keyword(s):  
Individual Differences ◽  
Repeated Measures ◽  
Polynomial Regression ◽  
Vastus Lateralis ◽  
Regression Analyses ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Leg Extension ◽  
Neuromuscular Responses ◽  
Muscle Actions

The purpose of this study was to compare the composite, inter-individual, and intra-individual differences in the patterns of responses for electromyographic (EMG) and mechanomyographic (MMG) amplitude (AMP) and mean power frequency (MPF) during fatiguing, maximal, bilateral, and isokinetic leg extension muscle actions. Thirteen recreationally active men (age = 21.7 ± 2.6 years; body mass = 79.8 ± 11.5 kg; height = 174.2 ± 12.7 cm) performed maximal, bilateral leg extensions at 180°·s−1 until the torque values dropped to 50% of peak torque for two consecutive repetitions. The EMG and MMG signals from the vastus lateralis (VL) muscles of both limbs were recorded. Four 2(Leg) × 19(time) repeated measures ANOVAs were conducted to examine mean differences for EMG AMP, EMG MPF, MMG AMP, and MMG MPF between limbs, and polynomial regression analyses were performed to identify the patterns of neuromuscular responses. The results indicated no significant differences between limbs for EMG AMP (p = 0.44), EMG MPF (p = 0.33), MMG AMP (p = 0.89), or MMG MPF (p = 0.52). Polynomial regression analyses demonstrated substantial inter-individual variability. Inferences made regarding the patterns of neuromuscular responses to fatiguing and bilateral muscle actions should be considered on a subject-by-subject basis.

Interlimb Neuromuscular Responses During Fatiguing, Bilateral, Leg Extension Exercise at a Moderate Versus High Load

Motor Control ◽  
2021 ◽  
Vol 25 (1) ◽  
pp. 59-74
Author(s):  
Taylor K. Dinyer ◽  
Pasquale J. Succi ◽  
M. Travis Byrd ◽  
Caleb C. Voskuil ◽  
Evangeline P. Soucie ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
High Load ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Leg Extension ◽  
Neuromuscular Responses ◽  
Power Frequency ◽  
The Central Nervous System ◽  
Common Drive ◽  
Repetitions To Failure

This study determined the load- and limb-dependent neuromuscular responses to fatiguing, bilateral, leg extension exercise performed at a moderate (50% one-repetition maximum [1RM]) and high load (80% 1RM). Twelve subjects completed 1RM testing for the bilateral leg extension, followed by repetitions to failure at 50% and 80% 1RM, on separate days. During all visits, the electromyographic (EMG) and mechanomyographic (MMG), amplitude (AMP) and mean power frequency (MPF) signals were recorded from the vastus lateralis of both limbs. There were no limb-dependent responses for any of the neuromuscular signals and no load-dependent responses for EMG AMP, MMG AMP, or MMG MPF (p = .301–.757), but there were main effects for time that indicated increases in EMG and MMG AMP and decreases in MMG MPF. There was a load-dependent decrease in EMG MPF over time (p = .032) that suggested variability in the mechanism responsible for metabolite accumulation at moderate versus high loads. These findings suggested that common drive from the central nervous system was used to modulate force during bilateral leg extension performed at moderate and high loads.

Is the V˙o 2 slow component dependent on progressive recruitment of fast-twitch fibers in trained runners?

2001 ◽  
Vol 90 (6) ◽  
pp. 2212-2220 ◽  
Author(s):  
F. Borrani ◽  
R. Candau ◽  
G. Y. Millet ◽  
S. Perrey ◽  
J. Fuchslocher ◽  
...  
Keyword(s):  
Slow Component ◽  
Vastus Lateralis ◽  
Classical Model ◽  
Average Frequency ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Lower Limb Muscles ◽  
Motor Unit Discharge ◽  
Gastrocnemius Muscles ◽  
Fast Twitch

The goal of this study was to use spectral analysis of EMG data to test the hypothesis that the O2 uptake (V˙o 2) slow component is due to a recruitment of fast fibers. Thirteen runners carried out a treadmill test with a constant speed, corresponding to 95% of the velocity associated with maximal V˙o 2. TheV˙o 2 response was fit with the classical model including three exponential functions. Electrical activity of six lower limb muscles (vastus lateralis, soleus, and gastrocnemius of both sides) was measured using electromyogram surface electrodes. Mean power frequency (MPF) was used to study the kinetics of the electromyogram discharge frequency. Three main results were observed: 1) a common pattern of the MPF kinetics in the six muscles studied was noted; 2) MPF decreased in the first part of the exercise, followed by an increase for all the muscles studied, but only the vastus lateralis, and gastrocnemius muscles of both sides increased significantly ( P < 0.05); and 3) the beginning of the MPF increase of the four muscles mentioned above corresponded with the beginning of the slow component. Our results suggest a progression in the average frequency of the motor unit discharge toward the high frequencies, which coheres with the hypothesis of the progressive recruitment of fast-twitch fibers during the V˙o 2 slow component. However, this interpretation must be taken with caution because MPF is the result of a balance between several phenomena.

The effect of leg extension training on the mean power frequency of the mechanomyographic signal

2000 ◽  
Vol 23 (6) ◽  
pp. 973-975 ◽  
Author(s):  
Tammy K. Evetovich ◽  
Terry J. Housh ◽  
Joseph P. Weir ◽  
Dona J. Housh ◽  
Glen O. Johnson ◽  
...  
Keyword(s):  
Mean Power ◽  
Mean Power Frequency ◽  
Leg Extension ◽  
Power Frequency ◽  
The Mean

Effects of Vascular Occlusion on Surface Electromyography and Muscle Oxygenation during Isometric Contraction

2004 ◽  
Vol 13 (4) ◽  
pp. 287-299 ◽  
Author(s):  
Eiji Yamada ◽  
Takashi Kusaka ◽  
Satoshi Tanaka ◽  
Satoshi Mori ◽  
Hiromichi Norimatsu ◽  
...  
Keyword(s):  
Isometric Contraction ◽  
Surface Electromyography ◽  
Near Infrared ◽  
Vascular Occlusion ◽  
Voluntary Contraction ◽  
Muscle Oxygenation ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Integrated Emg ◽  
The Right

Objective:To investigate changes in motor-unit activity and muscle oxygenation (MO) during isometric contraction with and without vascular occlusion using surface electromyography (EMG) and near-infrared spectroscopy.Design and Setting:MO and EMG of the right vastus medialis muscle were measured during isometric contraction at 30%, 50%, and 70% maximal voluntary contraction (MVC), with and without vascular occlusion.Participants:6 healthy men.Results:Integrated EMG (IEMG) and mean power frequency were significantly higher with vascular occlusion at 30% and 50% MVC. MO reduction at each load was significantly lower with vascular occlusion. A significant positive correlation was found between IEMG and changes in MO level under both conditions.Conclusions:These results suggest that oxygen supply to active muscles was impaired by occlusion and that type II fibers were then preferentially recruited, which suggests that hypertrophy occurs in low-intensity exercise in patients with limitations resulting from advanced age, pain, or postsurgery limitation.

Metabolic and neuromuscular responses at critical power from the 3-min all-out test

2013 ◽  
Vol 38 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Haley C. Bergstrom ◽  
Terry J. Housh ◽  
Jorge M. Zuniga ◽  
Daniel A. Traylor ◽  
Robert W. Lewis ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Critical Power ◽  
Peak Oxygen Consumption ◽  
Common Mechanism ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Emg Amplitude ◽  
Production Ratio ◽  
Significant Difference ◽  
Neuromuscular Responses

The purpose of this study was to determine the specific metabolic and neuromuscular responses at critical power (CP) from the 3-min all-out test. Nine men (mean ± SD: aged 23.7 ± 3.3 years) performed an incremental test for the determination of peak oxygen consumption (V̇O2peak) and gas exchange threshold. CP was estimated for each subject from the 3-min all-out test. Oxygen consumption (V̇O2), the ventilation versus carbon dioxide production ratio (V̇E/V̇CO2 ratio), electromyographic (EMG) amplitude, and EMG mean power frequency (MPF) were examined during exhaustive rides at CP for each subject. There was no significant difference between the V̇O2 at exhaustion (40.6 ± 7.5 mL·kg−1·min−1) and V̇O2peak (42.9 ± 7.3 mL·kg−1·min−1). Furthermore, there were significant increases in EMG amplitude and the V̇E/V̇CO2 ratio during the exhaustive rides at CP. There was, however, no significant change in EMG MPF over time. Therefore, the current findings indicated that the 3-min all-out test overestimated CP and the demarcation between the heavy- and severe-intensity domains. Specifically, the V̇O2, ventilatory, and EMG amplitude responses were consistent with those observed during continuous exercise in the severe exercise intensity domain. It is likely that the ventilatory and EMG amplitude responses were associated with a common mechanism of fatigue that is different from what affects EMG MPF.

Muscle Strength Assessment from the EMG Frequency Spectrum

1987 ◽  
Vol 31 (3) ◽  
pp. 310-314 ◽  
Author(s):  
Eui S. Jung
Keyword(s):  
Biceps Brachii ◽  
Muscle Tension ◽  
Maximum Voluntary Contraction ◽  
Power Spectra ◽  
Voluntary Contraction ◽  
The Other ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Strength Assessment ◽  
The Right

Assessment of a worker's strength is of great interest when evaluating the worker's ability to safely perform a job. Many previous studies have shown that surface electromyogram EMG amplitudes correlate well with muscle force. The present study furthered this concept by using EMG power spectra to achieve a quantified representation of true strength capability. Two groups of male subjects performed isometric elbow flexions while EMG was obtained from the right belly of biceps brachii. One group exercised their arms regularly while the other not. Six different levels of graded maximum voluntary contraction (%MVC) were selected to examine the relations between muscle tension and the mean power frequency (MPF) resulting from EMG power spectra. Resultant MPF's ranged between 50Hz and 70Hz in agreement with previous research results. Two-way ANOVA showed that, in the trained group, a significant increase in the MPF was found at near maximum contractions, whereas the other group failed to show any difference. Further analysis revealed that this increase in MPF was mainly caused by the power increase in the higher bandwidth (70—100Hz). A significant variation between subjects in both groups was also observed.

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