Joint analysis of spectrum and amplitude (JASA) of electromyograms applied for the indication of muscular fatigue in carpet weaving

2019 ◽  
Author(s):  
Narges Mortazavi ◽  
Teimour Allahyari ◽  
Hamid Reza Khalkhali ◽  
Mohammad Ali Sanjari
Keyword(s):  
Muscle Fatigue ◽  
Joint Analysis ◽  
Separate Analysis ◽  
Median Frequency ◽  
Mean Square ◽  
Spectral Parameters ◽  
Upper Trapezius ◽  
Emg Signal ◽  
Repetitive Tasks ◽  
High Prevalence

Abstract Background Hand carpet weaving requires prolonged static and repetitive tasks in a stationary and constrained postures, thus there is a high prevalence of muscle pain and fatigue and musculoskeletal disorders among carpet weavers.Methods This study aimed to determining the muscle fatigue in carpet weaving tasks by Joint Analysis of Spectral and amplitude (JASA (method. Two typical carpet weaving workstations were simulated in laboratory, and 12 female carpet weavers participated in this study. Electromyography (EMG) signals were recorded during work in bilateral upper trapezius and bilateral middle deltoid. The root mean square (RMS) and median frequency (MF) values were extracted from the raw EMG signal and used to estimate muscle load and fatigue. Joint analysis of spectral and amplitude (JASA (was performed for estimating the muscle fatigue.Results Result showed that in three out of four tested muscles, muscle fatigue and force decrease in workstation B were higher than those in workstation A.Conclusion In comparison to the simultaneous analysis of amplitude and spectral parameters in JASA method, it seems that the results are more reliable than the separate analysis of spectral and amplitude parameters. However further studies on other involved muscles in carpet weaving tasks were recommended.

scholarly journals An EMG Patch for the Real-Time Monitoring of Muscle-Fatigue Conditions During Exercise

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3108 ◽  
Author(s):  
Shing-Hong Liu ◽  
Chuan-Bi Lin ◽  
Ying Chen ◽  
Wenxi Chen ◽  
Tai-Shen Huang ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Real Time ◽  
Root Mean Square ◽  
The Body ◽  
Median Frequency ◽  
Mean Square ◽  
Sport Injuries ◽  
Physiological Measurement ◽  
The Real ◽  
Emg Signal

In recent years, wearable monitoring devices have been very popular in the health care field and are being used to avoid sport injuries during exercise. They are usually worn on the wrist, the same as sport watches, or on the chest, like an electrocardiogram patch. Common functions of these wearable devices are that they use real time to display the state of health of the body, and they are all small sized. The electromyogram (EMG) signal is usually used to show muscle activity. Thus, the EMG signal could be used to determine the muscle-fatigue conditions. In this study, the goal is to develop an EMG patch which could be worn on the lower leg, the gastrocnemius muscle, to detect real-time muscle fatigue while exercising. A micro controller unit (MCU) in the EMG patch is part of an ARM Cortex-M4 processor, which is used to measure the median frequency (MF) of an EMG signal in real time. When the muscle starts showing tiredness, the median frequency will shift to a low frequency. In order to delete the noise of the isotonic EMG signal, the EMG patch has to run the empirical mode decomposition algorithm. A two-electrode circuit was designed to measure the EMG signal. The maximum power consumption of the EMG patch was about 39.5 mAh. In order to verify that the real-time MF values measured by the EMG patch were close to the off-line MF values measured by the computer system, we used the root-mean-square value to estimate the difference in the real-time MF values and the off-line MF values. There were 20 participants that rode an exercise bicycle at different speeds. Their EMG signals were recorded with an EMG patch and a physiological measurement system at the same time. Every participant rode the exercise bicycle twice. The averaged root-mean-square values were 2.86 ± 0.86 Hz and 2.56 ± 0.47 Hz for the first and second time, respectively. Moreover, we also developed an application program implemented on a smart phone to display the participants’ muscle-fatigue conditions and information while exercising. Therefore, the EMG patch designed in this study could monitor the muscle-fatigue conditions to avoid sport injuries while exercising.

scholarly journals An Evaluation Method of Assessing the Low Back Muscle Fatigue in Manual Material Handling

2015 ◽  
pp. 467-475
Author(s):  
A. Komeili ◽  
X. Li ◽  
M. Gul ◽  
J. Lewick ◽  
M. El-Rich
Keyword(s):  
Muscle Fatigue ◽  
Evaluation Method ◽  
Fatigue Behavior ◽  
The Body ◽  
Median Frequency ◽  
Low Back ◽  
Body Parts ◽  
Back Muscle ◽  
Spectral Parameters ◽  
Repetitive Lifting

Workers in certain industries are exposed to high labor-intensive tasks. Low back pain (LBP) is widespread among construction workers (Hildebrandt, 1995) and is extremely prevalent, with every adult having up to an 85% chance of experiencing LBP at least once during his or her lifetime. Back-related complaints are more costly than those from any other body part for Alberta work-related claims. Ergonomic principles in addition to the engineering considerations should be included in the design of work stations to minimize the risk of injury for employees. In this study, we assessed the low back muscle fatigue due to lifting tasks. The objective was to investigate the changes in muscle activity and kinematics of the human body caused by fatigue due to repetitive lifting tasks. Three healthy male volunteers with no recent back complications were asked to complete 3 cycles of lifting task at the Syncrude Centre of the Glenrose Rehabilitation Hospital. Each cycle involved lifting a 15lb window frame for 20 times. Self? adhesive reflective markers were attached on the hands, trunk, and legs to measure displacements and rotation of the body parts while performing the task. Electromyography (EMG) sensors were placed on lower back muscles to record their activity. The muscle fatigue was investigated by studying change in EMG spectral parameters such as RMS, mean frequency (MNF), and median frequency (MDF) as well as physical condition of subjects due to repetitive lifting. The power frequency curve shifted to the low frequency when muscle fatigue occurred. As a result, the slope of the RMS, and MNF indicators were successful to describe the fatigue behavior expected.

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).

Myoelectric manifestations of fatigue in voluntary and electrically elicited contractions

1990 ◽  
Vol 69 (5) ◽  
pp. 1810-1820 ◽  
Author(s):  
R. Merletti ◽  
M. Knaflitz ◽  
C. J. De Luca
Keyword(s):  
Muscle Fatigue ◽  
Root Mean Square ◽  
Conduction Velocity ◽  
Time Course ◽  
Tibialis Anterior Muscle ◽  
Median Frequency ◽  
Mean Square ◽  
Myoelectric Signal ◽  
Physiological Factor ◽  
Voluntary Contractions

The time course of muscle fiber conduction velocity and surface myoelectric signal spectral (mean and median frequency of the power spectrum) and amplitude (average rectified and root-mean-square value) parameters was studied in 20 experiments on the tibialis anterior muscle of 10 healthy human subjects during sustained isometric voluntary or electrically elicited contractions. Voluntary contractions at 20% maximal voluntary contraction (MVC) and at 80% MVC with duration of 20 s were performed at the beginning of each experiment. Tetanic electrical stimulation was then applied to the main muscle motor point for 20 s with surface electrodes at five stimulation frequencies (20, 25, 30, 35, and 40 Hz). All subjects showed myoelectric manifestations of muscle fatigue consisting of negative trends of spectral variables and conduction velocity and positive trends of amplitude variables. The main findings of this work are 1) myoelectric signal variables obtained from electrically elicited contractions show fluctuations smaller than those observed in voluntary contractions, 2) spectral variables are more sensitive to fatigue than conduction velocity and the average rectified value is more sensitive to fatigue than the root-mean-square value, 3) conduction velocity is not the only physiological factor affecting spectral variables, and 4) contractions elicited at supramaximal stimulation and frequencies greater than 30 Hz demonstrate myoelectric manifestations of muscle fatigue greater than those observed at 80% MVC sustained for the same time.

scholarly journals Surface Electromyography Spectral Parameters for the Study of Muscle Fatigue in Swimming

2021 ◽  
Vol 3 ◽  
Author(s):  
Luca Puce ◽  
Ilaria Pallecchi ◽  
Lucio Marinelli ◽  
Laura Mori ◽  
Marco Bove ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Surface Electromyography ◽  
Maximum Speed ◽  
Median Frequency ◽  
Front Crawl ◽  
Spectral Parameters ◽  
Dry Land ◽  
Kinematic Data ◽  
Mechanical Fatigue ◽  
Multi Stage

The purpose of this study was to assess validity, stability and sensitivity, of 4 spectral parameters–median frequency (Fmed), mean frequency (Fmean), Dimitrov index (DI), and mean instant frequency (Fmi)–in measuring localized muscle fatigue in swimming and to investigate their correlation with the variations of kinematic data and mechanical fatigue. Electrophysiological measures of muscle fatigue were obtained in real-time during a 100 m front crawl test at maximum speed in 15 experienced swimmers, using surface electromyography in six muscles employed in front crawl, while kinematic data of swimming was measured from video analysis. Mechanical fatigue was measured as the difference between muscle strength prior to and immediately after the 100 m front crawl in a dry-land multi-stage isometric contraction test. Statistically significant fatigue (p &lt; 0.0001) was found for all spectral parameters in all muscles. Fmed and Fmean varied between 10 and 25%, DI between 50 and 150%, and Fmi between 5 and 10%. Strong correlation (Pearson r ≥ 0.5) with mechanical fatigue was found for all spectral parameters except for Fmi and it was strongest for Fmed and Fmean. From our study, it turns out that Fmed and Fmean are more valid and stable parameters to measure fatigue in swimming, while DI is more sensitive.

scholarly journals Electrical stimulator with mechanomyography-based real-time monitoring, muscle fatigue detection, and safety shut-off: a pilot study

2020 ◽  
Vol 65 (4) ◽  
pp. 461-468
Author(s):  
Jannatul Naeem ◽  
Nur Azah Hamzaid ◽  
Amelia Wong Azman ◽  
Manfred Bijak
Keyword(s):  
Muscle Fatigue ◽  
Real Time ◽  
Isometric Force ◽  
Mean Square ◽  
Clear Indication ◽  
Initial Value ◽  
Cord Injury ◽  
The Mean ◽  
Electrical Stimulator ◽  
Fatigue Detection

AbstractFunctional electrical stimulation (FES) has been used to produce force-related activities on the paralyzed muscle among spinal cord injury (SCI) individuals. Early muscle fatigue is an issue in all FES applications. If not properly monitored, overstimulation can occur, which can lead to muscle damage. A real-time mechanomyography (MMG)-based FES system was implemented on the quadriceps muscles of three individuals with SCI to generate an isometric force on both legs. Three threshold drop levels of MMG-root mean square (MMG-RMS) feature (thr50, thr60, and thr70; representing 50%, 60%, and 70% drop from initial MMG-RMS values, respectively) were used to terminate the stimulation session. The mean stimulation time increased when the MMG-RMS drop threshold increased (thr50: 22.7 s, thr60: 25.7 s, and thr70: 27.3 s), indicating longer sessions when lower performance drop was allowed. Moreover, at thr70, the torque dropped below 50% from the initial value in 14 trials, more than at thr50 and thr60. This is a clear indication of muscle fatigue detection using the MMG-RMS value. The stimulation time at thr70 was significantly longer (p = 0.013) than that at thr50. The results demonstrated that a real-time MMG-based FES monitoring system has the potential to prevent the onset of critical muscle fatigue in individuals with SCI in prolonged FES sessions.

scholarly journals Changes in electromyographic activity, mechanical power, and relaxation rates following inspiratory ribcage muscle fatigue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Antonio Sarmento ◽  
Guilherme Fregonezi ◽  
Maria Lira ◽  
Layana Marques ◽  
Francesca Pennati ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Low Frequency ◽  
Mechanical Power ◽  
Electromyographic Activity ◽  
Median Frequency ◽  
Relaxation Rates ◽  
Shortening Velocity ◽  
Inspiratory Muscles ◽  
Underlying Mechanisms

AbstractMuscle fatigue is a complex phenomenon enclosing various mechanisms. Despite technological advances, these mechanisms are still not fully understood in vivo. Here, simultaneous measurements of pressure, volume, and ribcage inspiratory muscle activity were performed non-invasively during fatigue (inspiratory threshold valve set at 70% of maximal inspiratory pressure) and recovery to verify if inspiratory ribcage muscle fatigue (1) leads to slowing of contraction and relaxation properties of ribcage muscles and (2) alters median frequency and high-to-low frequency ratio (H/L). During the fatigue protocol, sternocleidomastoid showed the fastest decrease in median frequency and slowest decrease in H/L. Fatigue was also characterized by a reduction in the relative power of the high-frequency and increase of the low-frequency. During recovery, changes in mechanical power were due to changes in shortening velocity with long-lasting reduction in pressure generation, and slowing of relaxation [i.e., tau (τ), half-relaxation time (½RT), and maximum relaxation rate (MRR)] was observed with no significant changes in contractile properties. Recovery of median frequency was faster than H/L, and relaxation rates correlated with shortening velocity and mechanical power of inspiratory ribcage muscles; however, with different time courses. Time constant of the inspiratory ribcage muscles during fatigue and recovery is not uniform (i.e., different inspiratory muscles may have different underlying mechanisms of fatigue), and MRR, ½RT, and τ are not only useful predictors of inspiratory ribcage muscle recovery but may also share common underlying mechanisms with shortening velocity.

scholarly journals Exhausting repetitive piano tasks lead to local forearm manifestation of muscle fatigue and negatively affect musical parameters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Etienne Goubault ◽  
Felipe Verdugo ◽  
Justine Pelletier ◽  
Caroline Traube ◽  
Mickaël Begon ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Sound Intensity ◽  
Musical Performance ◽  
Fundamental Aspect ◽  
Central Feature ◽  
Median Frequency ◽  
Piano Performance ◽  
Bipolar Electrodes ◽  
Right Hand ◽  
Extensor Muscles

AbstractMuscle fatigue is considered as a risk factor for developing playing-related muscular disorders among professional pianists and could affect musical performance. This study investigated in 50 pianists the effect of fatiguing repetitive piano sequences on the development of forearm muscle fatigue and on piano performance parameters. Results showed signs of myoelectric manifestation of fatigue in the 42-electromyographic bipolar electrodes positioned on the forearm to record finger and wrist flexor and extensor muscles, through a significant non-constant decrease of instantaneous median frequency during two repetitive Digital (right-hand 16-tones sequence) and Chord (right-hand chords sequence) excerpts, with extensor muscles showing greater signs of fatigue than flexor muscles. In addition, muscle fatigue negatively affected key velocity, a central feature of piano sound intensity, in both Digital and Chord excerpts, and note-events, a fundamental aspect of musicians’ performance parameter, in the Chord excerpt only. This result highlights that muscle fatigue may alter differently pianists’ musical performance according to the characteristics of the piece played.

Differences in muscular activation and fatigue for intermittent and constant load

2005 ◽  
Vol 5 (1) ◽  
pp. 43-56
Author(s):  
Danuta Roman-Liu ◽  
Krzysztof Kȩdzior
Keyword(s):  
External Force ◽  
Upper Limb ◽  
Muscle Activation ◽  
Regression Line ◽  
Constant Load ◽  
Median Frequency ◽  
Experimental Conditions ◽  
Emg Signal ◽  
Limb Posture ◽  
Muscular Activation

The aim of this study was to compare the influence of constant or intermittent load on muscle activation and fatigue. The analysis and assessment of muscular activation and fatigue was based on surface EMG measurements from eight muscles (seven muscles of the right upper limb and trapezius muscle). Two EMG signal parameters were analyzed for each of the experimental conditions distinguished by the value of the external force and the character of the load – constant or intermittent. The amplitude related to its maximum (AMP) and the slope of the regression line between time and median frequency (SMF) were the EMG parameters that were analyzed. The results showed that constant load caused higher muscular fatigue than intermittent load despite the lower value of the external force and lower muscle activation. Results suggest that additional external force might influence muscle activation and fatigue more than upper limb posture. The results of the study support the thesis that all biomechanical factors which influence upper limb load and fatigue (upper limb posture, external force and time sequences) should be considered when work stands and work processes are designed. They also indicate that constant load should be especially avoided.

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.

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