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1

Predicting muscle fatigue during dynamic contractions using wavelet analysis of surface electromyography signal

Shariatzadeh Mohammad Javad, Hadizadeh Hafshejani Ehsan, Mitchell Cameron J., Chiao Mu, Grecov Dana

Biocybernetics and Biomedical Engineering

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2023

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Vol. 43, no. 2

428--441

EN

Muscle fatigue is defined as a reduction in the capability of muscle to exert force or power. Although surface electromyography (sEMG) signals during exercise have been used to assess muscle fatigue, analyzing the sEMG signal during dynamic contractions is difficult because of the many signal distorting factors such as electrode movements, and variations in muscle tissue conductivity. Besides the non-deterministic and non-stationary nature of sEMG in dynamic contractions, no fatigue indicator is available to predict the ability of a muscle to apply force based on the sEMG signal properties. In this study, we designed and manufactured a novel wearable sensor system with both sEMG electrodes and motion tracking sensors to monitor the dynamic muscle movements of human subjects. We detected the state of muscle fatigue using a new wavelet analysis method to predict the maximum isometric force the subject can apply during dynamic contraction. Our method of signal processing consists of four main steps. 1- Segmenting sEMG signals using motion tracking signals. 2- Determine the most suitable mother wavelet for discrete wavelet transformation (DWT) based on cross-correlation between wavelets and signals. 3- Deoinsing the sEMG using the DWT method. 4- Calculation of normalized energy in different decomposition levels to predict maximal voluntary isometric contraction force as an indicator of muscle fatigue. The monitoring system was tested on healthy adults doing biceps curl exercises, and the results of the wavelet decomposition method were compared to well-known muscle fatigue indices in the literature.

2

The effect of cervical spine rotation on electromyographic activity of the trapezius and serratus anterior during selected shoulder complex movements

Jurecka Alicja, Żmijewska Kinga, Paplaczyk Małgorzata, Gądek Artur

Acta of Bioengineering and Biomechanics

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2022

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Vol. 24, no. 1

91--101

EN

The purpose of the study was the assessment of the effect of cervical spine rotation on the activity of the upper (UT) and lower (LT) trapezius and serratus anterior (SA) muscles during selected shoulder movements. Methods: The investigation included 33 healthy individuals (mean age ± SD: 22 ± 1.73 years). Bioelectrical activity of the right (R) and left (L) UT, LT, SA muscles was assessed during the following movements: elevation, flexion, abduction in the scapular and right coronal planes of the dominant (right) arm accompanied by three cervical spine positions (neutral, right rotation, left rotation). Results: RLT EMG activity was higher during right shoulder abduction with right spine rotation vs. that registered during abduction without cervical spine rotation ( p < 0.001). RUT EMG activity during right shoulder abduction was higher when abduction was associated with left cervical spine rotation ( p < 0.01) and lower during right shoulder flexing with right cervical spine rotation, compared to shoulder movements with neutral spine position ( p < 0.001). A higher RSA EMG activity was seen during shoulder flexing ( p < 0.001) and abducting ( p < 0.05) (both in the frontal and scapular plane) when the movement was performed with right cervical spine rotation, compared to RSA activity during shoulder movements without spinal rotation. Conclusions: The present results suggest that inclusion of appropriate cervical spine rotation during shoulder movements may result in improved activity of the trapezius and serratus anterior.

3

Hand movement recognition from sEMG signals using Fourier decomposition method

Fatimah Binish, Singh Pushpendra, Singhal Amit, Pachori Ram Bilas

Biocybernetics and Biomedical Engineering

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2021

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Vol. 41, no. 2

690--703

EN

Surface electromyogram (sEMG) provides a non-invasive way to collect EMG signals. The sEMG signals acquired from the muscles of the forearm can be used to recognize the hand grasps and gestures. In this work, an automatic recognition algorithm to identify hand movements using sEMG signals has been proposed. The signals are decomposed into Fourier intrinsic band functions (FIBFs) using the Fourier decomposition method (FDM). The features like entropy, kurtosis, and L1 norm are computed for each FIBF. Statistically relevant features are determined using the Kruskal Wallis test and used to train machine learning-based classifiers like support vector machine, k-nearest neighbor, ensemble bagged trees, and ensemble subspace discriminant. Two publicly available datasets are used to test the efficacy of the proposed algorithm. With an average accuracy of 99:49% on the UCI dataset and 93:53% on NinaPro DB5, the proposed method performs superior than the state-of-the-art algorithms. The performance of the proposed algorithm has also been analyzed in the presence of noise. The proposed method is based on Fourier theory, which makes it suitable for real-time implementation due to low computational complexity. It would help in the design of efficient and easy-to-use prosthetic hands.

4

Electromyographic evaluation of selected muscles during active hip extension in men treated McKenzie method

Jabłońska Magdalena, Fryzowicz Anna, Ogurkowska Małgorzata Barbara

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 3

23--31

EN

Purpose: The aim of this study was to evaluate objective results of short-term treatment with the use of electromyography and to determine changes in muscle recruitment during the prone hip extension test in individuals with chronic low back pain who underwent the McKenzie treatment. Methods: The studied group consisted of 17 male office workers aged 33–55 who underwent two experimental sessions comprising of 3 measurements and the McKenzie method of mechanical diagnosis and therapy. Electromyographic examination of selected muscles was performed during the test in order to assess changes in their activity before and after the McKenzie method and the Visual Analogue Scale was used to assess the level of pain. Results: There was a tendency towards significance at the beginning of activation between the first and second test for the left erector spinae muscle ( p = 0.0684). In 18% of patients, the onset activation time decreased, which is indicative of correct direction of changes. No statistically significant changes were observed in the remaining muscles. Statistical significance ( p = 0.0131) was observed between the first and third test for the left erector spinae muscle. A decrease in the onset activation time was observed in 75% of the subjects. Effectiveness increased by as much as 57%. The level of pain decreased in the third test compared to the first one ( p = 0.0240). However, the change in pain sensations between the first and second test was not statistically significant. Conclusions: The study showed objective changes in the activation sequence of selected muscles and subjective changes in pain following short term McKenzie therapy.

5

Disbalance and fatigue of the spinal extensors as one of the causes of the overload disease of the lumbar spine

Zyznawska Joanna, Frankowski Grzegorz, Wodka-Natkaniec Ewa, Kołomańska Daria, Boczoń Kamila, Kulesa-Mrowiecka Małgorzata

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 3

119--125

EN

The aim of the study was to find out whether among young active people – the future healthcare professionals – there is a risk of developing lumbar spine overload disease depending on the occurrence of the disbalance of paravertebral muscles and to assess the fatigue of the examined muscles depending on the body position during the work. Methods: The study involved 50 randomly selected students of physiotherapy and emergency medical services of a mean age of 21 years. The surface electromyography (sEMG) was used to measure the activity level of spinal extensors of the cervical and lumbar spine. The statistical analysis of the results was made using the RStudio software. Results: Study shows that the majority of the examined students had a slight asymmetry between the bioelectric activity of the right- and left-side dorsal extensor bands, both in the cervical and lumbar sections (right side 118.6 Hz / left side 115.7 Hz / extension and 98.6 Hz / 95.5 Hz /flexion). Depending on the position, significant fatigue in the examined muscles was found ( p < 0.05). Conclusions: The experiment showed a slight disbalance in the average bioelectromyographic activity in the area of spinal extensors during their symmetrical work. This can be the basis for the development of the overload disease in the weaker muscle parts, which generate more fatigue during the activity. It is worth to carry out similar tests in a much greater group, taking the longer-lasting muscular effort into account.

6

Bioelectric activity of mastication muscles and the functional impairment risk groups concerning the masticatory muscles

Zieliński G., Suwała M., Ginszt M., Szkutnik J., Majcher P.

Acta of Bioengineering and Biomechanics

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2018

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Vol. 20, no. 4

161--166

EN

Temporomandibular disorders affect from 5 to 12 percent of the population, occurring almost twice as often in women than in men. The painful form of temporomandibular disorders is one of the most common musculoskeletal disorders causing pain. The chronic form is associated with changes in activity of the masticatory muscles and can lead to sleep problems, reduction of emotional state and worsening of quality of life. Methods: 66 women were included in the study group. The study was composed of a clinical evaluation of temporomandibular disorders and assessment of the masticatory muscle activities using surface electromyography. The anterior part of the temporalis muscle and the superficial part of the masseter muscle were evaluated during teeth clenching on cotton rolls. The symmetric activity index was calculated from the results of electromyographic activity. Based on the activity and symmetric activity index values, subjects were qualified to the risk group of temporomandibular disorders. Results: Twenty people (30.3 percent) qualified for the temporomandibular disorders risk group. In the temporomandibular disorders risk group, the mean symmetric activity index value of the anterior part of the temporal muscle was 72.6 percent and the mean electromyographic activity was 143.94 microvolts. In the masseter muscle, the mean symmetric activity index value was 67.7 percent and the mean electromyographic activity was 155.33 microvolts. Conclusions: Temporomandibular disorders may develop in 30.3 percent of examined women. The research should be continued to determine the temporomandibular disorders risk group, which may enable for the appropriate prevention of the development of dysfunctions in the stomatognathic system.

7

MLPNN and kNN Based Classification of sEMG Signal for Myoelectric Control of Upper Limb Prosthesis

Negi Sachin, Kumar Yatindra, Mishra V. M

Annals of Computer Science and Information Systems

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2017

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Vol. 10

269--292

EN

Analysis of sEMG signal has been an emerging field for the myoelectric control of upper limb prosthesis. The objective of present work is to obtain the performance measures like accuracy, sensitivity, specificity and positive predictivity using MLPNN with back propagation algorithm. Using MLPNN classifier, an average classification accuracy of 93.71\% was achieved over ten subjects for the combination of [MAV1, WL, AAC, ZC, and WAMP] features. Next the classification accuracy is obtained with kNN classifier for k= 3, 5, and 7. The results showed that average classification accuracy of 93.06\% is achieved using kNN and it is better than MLPNN in terms of time and simplicity.

8

Analiza biomechaniki kręgosłupa w jeździectwie

Szypielewicz S., Andryszczyk M., Siemianowski P., Topoliński T.

Aktualne Problemy Biomechaniki

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2017

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z. 13

57--62

PL

Niniejsza praca przedstawia możliwości analizy motoryki jeźdźca podczas jazdy konnej oraz doskonalenia treningu jeździeckiego poprzez wykorzystanie pomiarów zmian kątów kręgosłupa oraz potencjałów elektrycznych mięśni pleców jeźdźca.

EN

The following research shows the possibilities of motorics analysis of horse-rider in equine sports and improvement of equine training throughout using the progressive measure technologies. Researches includes EMG potential measures of back muscles and measures of angle changes between spine segments.

9

Biomechanics of the shoulder girdle : a case study on the effects of union rugby tackles

Faria L., Campos B., Jorge R. N.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 3

115--127

EN

Purpose: The shoulder girdle is a complex system, comprised by a kinematic chain and stabilizers. Due to the delicate equilibrium and synchronism between mobility and stability, high external loads may compromise its physiology, increasing the risk of injuries. Thus, this study intends to fully characterize the effects of a rugby tackle on the shoulder’s anatomy and physiology. Methods: For the experimental procedures, a matrix of pressure sensors was used, based on the Teckscan® pressure in-soles, force plates, an isokinetic dynamometer and sEMG (surface electromyography). Results: The anterosuperior region of the shoulder girdle confirmed the highest pressure values during impact (100 kPa to 200 kPa). Also, the right and left feet performed a vertical peak force of 1286 N (1.4 BW) and 1998 N (2.21 BW), respectively. The muscular activity of the shoulder muscles decreased after performing multiple tackles. Conclusions: During a tackle, the clavicle, scapula, trapezius and acromioclavicular joint are the anatomical structures with higher risk of injury. Also, the strike force on the feet decreases for stability purposes. After performing multiple impacts the muscular activity of the trapezius and rotator cuff muscles decreases, which may lead, in the long-term, to instability of the shoulder and inefficiency of the scapulohumeral rhythm.

10

Obsługa maszyn ręcznych z napędem elektrycznym – obciążenie układu mięśniowo-szkieletowego

Dąbrowski A., Tokarski T.

Maszyny Elektryczne : zeszyty problemowe

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2016

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Nr 1 (109)

57--61

PL

Zapotrzebowanie na maszyny ręczne, w tym z napędem elektrycznym, wzrastało na świecie średnio o 4,4% każdego roku osiągając w 2015 roku wartość ok. 27,3 mld USD. Stosowanie tych maszyn powoduje powstawanie zagrożeń dla układu mięśniowo szkieletowego. Na kończyny górne operatora przenoszone są momenty obrotowe (tzw. momenty utyku – np. skutek zakleszczenia narzędzia w materiale obrabianym). Podczas badań symulowano obciążenie mięśni operatorów, trzymających za uchwyty pracujące dwa rodzaje wiertarek elektrycznych (o różnej mocy). Moment przenoszony na ręce operatorów powstawał na skutek zahamowania ruchu narzędzi przez hamownię. Do badań zastosowano aparaturę służącą do pomiaru aktywności elektrycznej mięśni – elektromiografię powierzchniową (sEMG). Badano obciążenie mięśni przedramienia, ramienia i obręczy barkowej - lewej i prawej części ciała. Zaobserwowano różne wartości obciążenia mięśni w zależności od pionowego i poziomego ustawienia maszyny ręcznej oraz od sposobu trzymania wiertarki za uchwyty (jedną ręką, oburącz). Dla ustalonych momentów generowanych przez maszyny, wybrane mięśnie miały większe obciążenie w odniesieniu do pozostałych. Przy projektowaniu i stosowaniu maszyn ręcznych na stanowiskach pracy należy brać pod uwagę najbardziej niekorzystne warunki obciążenia. Uwzględnienie takich warunków pozwoli zapobiec powstawaniu dolegliwości lub urazów układu mięśniowo – szkieletowego operatorów.

EN

Demand for hand-held power tools, including electric tools rose in the world on average by the 4.4% per year, achieving in 2015 the value of ca. 27.3 billion USD. The use of these machines causes the risk for musculoskeletal system. Torques are being transferred to upper limbs of the operator (so called pull-out torque - e.g. the effect of tool jam in the workpiece). During the tests loads of operators muscles was simulated, during holding by handles of two working types of hand held electric drills (with different power). The torque transferred to the operators hands was the result of tools move being stopped on the engine test bench. The testing apparatus was used to measure electric activity of the muscles – surface electromyography (sEMG). There were measured load of the muscles of the forearm, arm and shoulder girdle - the left and right parts of the body was recorded. Different values of muscle load were observed, depending on the vertical and horizontal position of the hand-held machine and the way of holding the drill grips (one hand, both hands). For fixed moments generated by the machines, the selected muscles had greater workload in relation to others. Therefore, when designing and applying these machines at workplaces the most unfavorable load conditions should be taken into account. It will help to prevent musculoskeletal disorders or injuries of the operators.

11

Investigation of probability density functions in modeling sample distribution of surface electromyographic (sEMG) signals

Rosa I. G., Garcia M. A. C., Souza M. N.

Archives of Control Sciences

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2013

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Vol. 23, no. 4

381--393

EN

The surface electromyography signal (sEMG) has been typically modeled as a Gaussian random process. However, some authors have reported that the probability density functions (pdfs) associated with the sample distribution of sEMG signal exhibits a more peaked shape than one could expected for a Gaussian pdf. This work aimed to reinvestigate the profile of the sEMG pdfs during five different load levels of isometric contractions of biceps brachii muscle, and compared the adequacy of four different pdfs (Gaussian, Logistic, Cauchy, and Laplacian) in describing the sample distribution of such signal. Experimental pdfs were estimated for each subject and load condition. The comparison between experimental pdfs obtained from sEMG data of forty volunteers and four theoretical pdfs was performed by fitting these functions to its experimental counterpart, and using a mean absolute errors in the assessment of the best fit. On average, the Logistic pdf seemed to be the best one to describe the sample distribution of sEMG signal, although the probabilistic results, considering binomial trials, were significant for both Gaussian and Logistic pdfs.

12

Wyznaczanie sił mięśniowych podczas chodu dzieci zdrowych

Głowacka A., Świtoński E., Michnik R.

Aktualne Problemy Biomechaniki

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2012

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z. 6

31--36

13

Effects of Neutral Posture on Muscle Tension During Computer Use

Dowler E., Kappes B., Fenaughty A., Pemberton G.

International Journal of Occupational Safety and Ergonomics

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2001

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Vol. 7, No. 1

61--78

EN

This study focused on developing a new approach to seated work positions as conducted on 67 office workers who use a Visual Display Terminal (VDT) as a major function of their working day. Muscle tension was measured by surface electromyography (sEMG) while participants were asked to adopt 4 selected working postures. Pain was measured before and after ergonomic intervention on the Nordic scale, which was modified for this study. Adjustable workstations were used to place participants in desired positions during the clinical testing sessions and the extended intervention period. Results indicate the effects of this ergonomic intervention may have positive effects on muscle tension and pain, significant enough to encourage employers to implement training and workstation modifications following these guidelines.