Noise and muscle contraction affecting vigilance task performance

2005 ◽  
Vol 4 (3) ◽  
pp. 157-171
Author(s):  
Duane C. Button ◽  
David G. Behm ◽  
Michael Holmes ◽  
Scott N. Mackinnon
Keyword(s):  
Reaction Time ◽  
Muscle Contraction ◽  
Task Performance ◽  
Video Game ◽  
Movement Time ◽  
Maximum Voluntary Contraction ◽  
Vigilance Task ◽  
Voluntary Contraction ◽  
Neuromuscular Fatigue ◽  
Muscle Contraction Intensity

The objective of this study was to determine the effects of muscle contraction intensity, neuromuscular fatigue, and noise on vigilance performance. Dependent variables included simple (reaction time and movement time) and complex (video game: Tetris) vigilance tasks (SVT and CVT respectively) and maximum voluntary contraction (MVC) force and activation. Vigilance tasks and MVC were randomly allocated to 5 minute blocks during a pre-test. Following the pre-test, the tests were again randomly allocated within three, 15 minute testing sessions over 65 minutes, while 1) being exposed to high (95 dB (A)) or low (53 dB (A)) levels of noise, and 2) performing muscle contractions at 20% and 5% of MVC, or no contractions. Ninety-five (95) dB (A) noise increased (p ≤ 0.01) SVT (reaction time and movement time combined) by 11.2% and decreased (p ≤ 0.01) CVT by 20%. Both 20% and 5% MVC impaired SVT and CVT to a similar extent, while no changes were seen with no contractions. Furthermore, neuromuscular fatigue had no apparent effect on vigilance task performance. These findings suggest that the distraction of noise and divided attention between muscle contraction and a vigilance task decreases performance.

Reaction Time and Intent to Respond

1966 ◽  
Vol 23 (3_suppl) ◽  
pp. 1108-1110
Author(s):  
Roy Yensen
Keyword(s):  
Reaction Time ◽  
Movement Time ◽  
Muscle Tension ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Prime Movers

It is suggested that increases in muscle tension may have occurred just prior to the initiation of the response under conditions of artificially increased mass and that these may have contributed to Whitley's (1966) finding of significantly faster RT under this condition. Following brief discussion of variation in intent to move more or less strongly, it is postulated that the exertion of near maximum voluntary contraction of the prime movers in the initiation of a movement would decrease the RT and that such RT would correlate positively with movement time.

scholarly journals Motor planning perturbation: muscle activation and reaction time

2018 ◽  
Vol 120 (4) ◽  
pp. 2059-2065
Author(s):  
Stefan Delmas ◽  
Agostina Casamento-Moran ◽  
Seoung Hoon Park ◽  
Basma Yacoubi ◽  
Evangelos A. Christou
Keyword(s):  
Reaction Time ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Maximum Voluntary Contraction ◽  
Motor Planning ◽  
Reaction Time Task ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Time Interval ◽  
Voluntary Activity

Reaction time (RT) is the time interval between the appearance of a stimulus and initiation of a motor response. Within RT, two processes occur, selection of motor goals and motor planning. An unresolved question is whether perturbation to the motor planning component of RT slows the response and alters the voluntary activation of muscle. The purpose of this study was to determine how the modulation of muscle activity during an RT response changes with motor plan perturbation. Twenty-four young adults (20.5 ±1.1 yr, 13 women) performed 15 trials of an isometric RT task with ankle dorsiflexion using a sinusoidal anticipatory strategy (10–20% maximum voluntary contraction). We compared the processing part of the RT and modulation of muscle activity from 10 to 60 Hz of the tibialis anterior (primary agonist) when the stimulus appeared at the trough or at the peak of the sinusoidal task. We found that RT ( P = 0.003) was longer when the stimulus occurred at the peak compared with the trough. During the time of the reaction, the electromyography (EMG) power from 10 to 35 Hz was less at the peak than the trough ( P = 0.019), whereas the EMG power from 35 to 60 Hz was similar between the peak and trough ( P = 0.92). These results suggest that perturbation to motor planning lengthens the processing part of RT and alters the voluntary activation of the muscle by decreasing the relative amount of power from 10 to 35 Hz. NEW & NOTEWORTHY We aimed to determine whether perturbation to motor planning would alter the speed and muscle activity of the response. We compared trials when a stimulus appeared at the peak or trough of an oscillatory reaction time task. When the stimulus occurred at the trough, participants responded faster, with greater force, and less EMG power from 10-35 Hz. We provide evidence that motor planning perturbation slows the response and alters the voluntary activity of the muscle.

scholarly journals Effects of whole-body vibrations on neuromuscular fatigue: a study with sets of different durations

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10388
Author(s):  
Miloš Kalc ◽  
Ramona Ritzmann ◽  
Vojko Strojnik
Keyword(s):  
High Frequency ◽  
Maximum Voluntary Contraction ◽  
Peak Torque ◽  
Voluntary Contraction ◽  
Neuromuscular Fatigue ◽  
Voluntary Activation ◽  
Whole Body ◽  
Peripheral Fatigue ◽  
Single Twitch ◽  
Whole Body Vibrations

Background Whole body vibrations have been used as an exercise modality or as a tool to study neuromuscular integration. There is increasing evidence that longer WBV exposures (up to 10 minutes) induce an acute impairment in neuromuscular function. However, the magnitude and origin of WBV induced fatigue is poorly understood. Purpose The study aimed to investigate the magnitude and origin of neuromuscular fatigue induced by half-squat long-exposure whole-body vibration intervention (WBV) with sets of different duration and compare it to non-vibration (SHAM) conditions. Methods Ten young, recreationally trained adults participated in six fatiguing trials, each consisting of maintaining a squatting position for several sets of the duration of 30, 60 or 180 seconds. The static squatting was superimposed with vibrations (WBV30, WBV60, WBV180) or without vibrations (SHAM30, SHAM60, SHAM180) for a total exercise exposure of 9-minutes in each trial. Maximum voluntary contraction (MVC), level of voluntary activation (%VA), low- (T20) and high-frequency (T100) doublets, low-to-high-frequency fatigue ratio (T20/100) and single twitch peak torque (TWPT) were assessed before, immediately after, then 15 and 30 minutes after each fatiguing protocol. Result Inferential statistics using RM ANOVA and post hoc tests revealed statistically significant declines from baseline values in MVC, T20, T100, T20/100 and TWPT in all trials, but not in %VA. No significant differences were found between WBV and SHAM conditions. Conclusion Our findings suggest that the origin of fatigue induced by WBV is not significantly different compared to control conditions without vibrations. The lack of significant differences in %VA and the significant decline in other assessed parameters suggest that fatiguing protocols used in this study induced peripheral fatigue of a similar magnitude in all trials.

scholarly journals Relationship between Isometric Muscle Force and Fractal Dimension of Surface Electromyogram

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Matteo Beretta-Piccoli ◽  
Gennaro Boccia ◽  
Tessa Ponti ◽  
Ron Clijsen ◽  
Marco Barbero ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Muscle Contraction ◽  
Biceps Brachii ◽  
Isometric Force ◽  
Voluntary Contraction ◽  
Experimental Conditions ◽  
Surface Electromyogram ◽  
Mean Frequency ◽  
Muscle Contraction Intensity ◽  
The Relationship

The relationship between fractal dimension of the surface electromyogram (sEMG) and the intensity of muscle contraction is still controversial in simulated and experimental conditions. To support the use of fractal analysis to investigate myoelectric fatigue, it is crucial to establish the interdependence between fractal dimension and muscle contraction intensity. We analyzed the behavior of fractal dimension, conduction velocity, mean frequency, and average rectified value in twenty-eight volunteers at nine levels of isometric force. sEMG was obtained using bidimensional arrays in the biceps brachii muscle. The values of fractal dimension and mean frequency increased with force unless a plateau was reached at 30% maximal voluntary contraction. Overall, our findings suggest that, above a certain level of force, the use of fractal dimension to evaluate the myoelectric manifestations of fatigue may be considered, regardless of muscle contraction intensity.

scholarly journals Maximum voluntary muscle contraction and fatigue in multibacillary leprosy

2020 ◽  
Vol 33 ◽  
Author(s):  
Luciane Lobato Sobral ◽  
Marcio Clementino de Souza Santos ◽  
Larissa Salgado de Oliveira Rocha ◽  
Bianca Callegari ◽  
Givago da Silva Souza ◽  
...  
Keyword(s):  
Muscle Contraction ◽  
Fatigue Test ◽  
Healthy Subjects ◽  
Maximum Voluntary Contraction ◽  
Onset Time ◽  
Voluntary Contraction ◽  
Control Group ◽  
Time Interval ◽  
Leprosy Patients ◽  
Multibacillary Leprosy

Abstract Introduction: The impairment of muscle strength and fatigue in leprosy remains a problem that requires careful attention to avoid or minimize its progression, as well as prevention of disabilities and deformities. Objective: To investigate the maximum voluntary contraction and time to muscle fatigue in leprosy patients. Method: A total of 21 leprosy patients and 21 healthy subjects completed the sample. The method used to determine the maximum voluntary contraction (MVC) of the handgrip followed the recommendation of the American Society of Hand Therapists with the use of a hydraulic hand grip dynamometer. The test was performed three times with each hand, with a time interval of 60 seconds between successive trials. The subject was instructed to perform a maximal isometric force against the dynamometer for 5 seconds. The peaks were recorded and used for the fatigue test. For the fatigue test, we recorded the electromyogram of the forearm muscles to offline determine the onset time for the muscle contraction (14 bits, Miograph 2 USB®, Miotec, Brazil). Results: Leprosy patients had lower MVC compared with healthy subjects (p > 0.05), both in the dominant and the non-dominant hands. The time to fatigue in the leprosy and control groups was similar (p < 0.05). We observed that leprosy patients had more contractions than the healthy subjects (22.6 ± 11.8 contractions for the leprosy group vs. 12.3 ± 6.9 contractions for the control group, p > 0.05). Conclusion: Multibacillary leprosy patients lost muscle force without modifying the resistance to fatigue.

Mechanical effects of muscle contraction do not blunt sympathetic vasoconstriction in humans

2005 ◽  
Vol 289 (4) ◽  
pp. H1610-H1617 ◽  
Author(s):  
Brett S. Kirby ◽  
Rachel R. Markwald ◽  
Erica G. Smith ◽  
Frank A. Dinenno
Keyword(s):  
Muscle Contraction ◽  
Lower Body Negative Pressure ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Metabolic Demand ◽  
Mechanical Effects ◽  
Sympathetic Vasoconstriction ◽  
Functional Sympatholysis ◽  
Forearm Vascular Conductance ◽  
Vascular Beds

Sympathetic vasoconstrictor responses are blunted in the vascular beds of contracting muscle (functional sympatholysis), but the mechanism(s) have been difficult to elucidate. We tested the hypothesis that the mechanical effects of muscle contraction blunt sympathetic vasoconstriction in human muscle. We measured forearm blood flow (Doppler ultrasound) and calculated the reductions in forearm vascular conductance (FVC) in response to reflex increases in sympathetic activity evoked via lower body negative pressure (LBNP). In protocol 1, eight young adults were studied under control resting conditions and during simulated muscle contractions using rhythmic forearm cuff inflations (20 inflations/min) with cuff pressures of 50 and 100 mmHg with the arm below heart level (BH), as well as 100 mmHg with the arm at heart level (HL). Forearm vasoconstrictor responses (%ΔFVC) during LBNP were −26 ± 2% during control conditions and were not blunted by simulated contractions (range = −31 ± 3% to −43 ± 6%). In protocol 2, eight subjects were studied under control conditions and during rhythmic handgrip exercise (20 contractions/min) using workloads of 15% maximum voluntary contraction (MVC) at HL and BH (similar metabolic demand, greater mechanical muscle pump effect for the latter) and 5% MVC BH alone and in combination with superimposed forearm compressions of 100 mmHg (similar metabolic demand, greater mechanical component of contractions for the latter). The forearm vasoconstrictor responses during LBNP were blunted during 15% MVC exercise with the arm at HL (−1 ± 3%) and BH (−2 ± 3%) compared with control (−25 ± 3%; both P < 0.005) but were intact during both 5% MVC alone (−24 ± 4%) and with superimposed compressions (−23 ± 4%). We conclude that mechanical effects of contraction per se do not cause functional sympatholysis in the human forearm and that this phenomenon appears to be coupled with the metabolic demand of contracting skeletal muscle.

scholarly journals Computation and Evaluation of Features of Surface Electromyogram to Identify the Force of Muscle Contraction and Muscle Fatigue

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sridhar P. Arjunan ◽  
Dinesh K. Kumar ◽  
Ganesh Naik
Keyword(s):  
Muscle Contraction ◽  
Muscle Fatigue ◽  
Root Mean Square ◽  
Linear Regression Analysis ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Median Frequency ◽  
Mean Square ◽  
Surface Electromyogram ◽  
The Relationship

The relationship between force of muscle contraction and muscle fatigue with six different features of surface electromyogram (sEMG) was determined by conducting experiments on thirty-five volunteers. The participants performed isometric contractions at 50%, 75%, and 100% of their maximum voluntary contraction (MVC). Six features were considered in this study:normalised spectral index (NSM5), median frequency, root mean square, waveform length, normalised root mean square (NRMS), and increase in synchronization (IIS) index. Analysis of variance (ANOVA) and linear regression analysis were performed to determine the significance of the feature with respect to the three factors: muscle force, muscle fatigue, and subject. The results show that IIS index of sEMG had the highest correlation with muscle fatigue and the relationship was statistically significant (P<0.01), while NSM5 associated best with level of muscle contraction (%MVC) (P<0.01). Both of these features were not affected by the intersubject variations (P>0.05).

scholarly journals The Effect of Mechanical Vibration Stimulation of Perception Subthreshold on the Muscle Force and Muscle Reaction Time of Lower Leg

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Huigyun Kim ◽  
Kiyoung Kwak ◽  
Dongwook Kim
Keyword(s):  
Reaction Time ◽  
Vibration Frequency ◽  
Muscle Force ◽  
Maximum Voluntary Contraction ◽  
Mechanical Vibration ◽  
Lower Leg ◽  
Voluntary Contraction ◽  
Perception Threshold ◽  
Measurement Results ◽  
Analysis System

The objective of this study is to investigate the effect of mechanical vibration stimulation on the muscle force and muscle reaction time of lower leg according to perception threshold and vibration frequency. A vibration stimulation with perception threshold intensity was applied on the Achilles tendon and tibialis anterior tendon. EMG measurement and analysis system were used to analyze the change of muscle force and muscle reaction time according to perception threshold and vibration frequency. A root-mean-square (RMS) value was extracted using analysis software and Maximum Voluntary Contraction (MVC) and Premotor Time (PMT) were analyzed. The measurement results showed that perception threshold was different from application sites of vibration frequency. Also, the muscle force and muscle reaction time showed difference according to the presence of vibration, frequency, and intensity. This result means that the vibration stimulation causes the change on the muscle force and muscle reaction time and affects the muscles of lower leg by the characteristics of vibration stimulation.

Functional difference in short- and long-latency interhemispheric inhibitions from active to resting hemisphere during a unilateral muscle contraction

2014 ◽  
Vol 111 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Kazumasa Uehara ◽  
Takuya Morishita ◽  
Shinji Kubota ◽  
Masato Hirano ◽  
Kozo Funase
Keyword(s):  
Muscle Contraction ◽  
Primary Motor Cortex ◽  
Maximum Voluntary Contraction ◽  
Conditioning Stimulus ◽  
Voluntary Contraction ◽  
Muscle Contractions ◽  
Functional Difference ◽  
Experimental Conditions ◽  
Long Latency ◽  
Significant Difference

The aim of the present study was to investigate whether there is a functional difference in short-latency (SIHI) and long-latency (LIHI) interhemispheric inhibition from the active to the resting primary motor cortex (M1) with paired-pulse transcranial magnetic stimulation during a unilateral muscle contraction. In nine healthy right-handed participants, IHI was tested from the dominant to the nondominant M1 and vice versa under resting conditions or during performance of a sustained unilateral muscle contraction with the right or left first dorsal interosseous muscle at 10% and 30% maximum voluntary contraction. To obtain measurements of SIHI and LIHI, a conditioning stimulus (CS) was applied over the M1 contralateral to the muscle contraction, followed by a test stimulus over the M1 ipsilateral to the muscle contraction at short (10 ms) and long (40 ms) interstimulus intervals. We used four CS intensities to investigate SIHI and LIHI from the active to the resting M1 systematically. The amount of IHI during the unilateral muscle contractions showed a significant difference between SIHI and LIHI, but the amount of IHI during the resting condition did not. In particular, SIHI during the muscle contractions, but not LIHI, significantly increased with increase in CS intensity compared with the resting condition. Laterality of IHI was not detected in any of the experimental conditions. The present study provides novel evidence that a functional difference between SIHI and LIHI from the active to the resting M1 exists during unilateral muscle contractions.

A Study of the Application of Fitts' Law to Selected Cerebral Palsied Adults

1993 ◽  
Vol 77 (3_suppl) ◽  
pp. 1107-1117 ◽  
Author(s):  
Pedro E. Bravo ◽  
Miriam LeGare ◽  
Albert M. Cook ◽  
Susan Hussey
Keyword(s):  
Cerebral Palsy ◽  
Reaction Time ◽  
Video Game ◽  
Movement Time ◽  
Limited Range ◽  
Normal Group ◽  
Range Of Movement ◽  
Fitts Law ◽  
Index Of Difficulty ◽  
The Individual

Fitts' Law was applied to the evaluation of discrete aimed arm movements in one dimension performed by 6 adults with cerebral palsy and 6 adults with normal movement. Targets (1.27, 3.81, 6.35, 8.89 cm in width) placed at distances of 20.32, 30.48, 40.64, and 50.80 cm provided Indices of Difficulty of 2.19 to 6.32 bits. A video game was used for the signal to move. The t tests for corrected means showed that the cerebral palsied group had greater reaction and movement times than the normal group. Linear regression analyses for pooled data and for the individual cerebral palsied subjects showed (a) no relationship between reaction time and Index of Difficulty for either group and (b) a negative, linear relationship between reaction time and Index of Difficulty for 1 cerebral palsied subject. Movement time was linearly and positively related to the Index of Difficulty for the normal group but not for the cerebral palsied group. Two cerebral palsied subjects had movement times which conformed to Fitts' Law. While the exceptions to Fitts' Law may be due to the limited range of movement and spasticity caused by severe cerebral palsy, there are indications that two of the cerebral palsied subjects were performing ballistic rather than visually guided aimed movements. Fitts' Law may still apply when the distances and target positions are individualized to conform to subjects' specific limitations and when the signal to move is auditory rather than visual.

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