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Hua A, Bai J, Hao Z, Yang Y, Zhang R, Wang J. Linear spectrum and non-linear complexity features of lumbar muscle surface electromyography between people with and without non-specific chronic low back pain during Biering-Sorensen test. J Electromyogr Kinesiol 2023; 69:102742. [PMID: 36709643 DOI: 10.1016/j.jelekin.2023.102742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 12/13/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023] Open
Abstract
PURPOSE This study aimed to investigate the electromyographic parameters of lumbar muscles during the Biering-Sorensen test (BST) in people with and without non-specific chronic low back pain (NCLBP). MATERIALS AND METHODS Thirteen healthy controls and thirteen NCLBP patients participated in the current study, where they performed the 90s-BST, while the surface electromyography (sEMG) was recorded from the erector spinae (ES) at L1 and L3 level and lumbar multifidus (LM) at L5 level, bilaterally. Spectral and nonlinear analyses were applied by calculating mean power frequency (MPF), fractal dimension (FD) and the percentage of determinism (%DET) in the 10-second non-overlapping time-windows and EMG-EMG coherence during the first half and second half of the BST. Also, the slopes of the linear fitting curves of MPF, FD and %DET were calculated. RESULTS NCLBP group had significantly lower rates of changes in MPF, FD and %DET compared to asymptomatic controls in the ES(L3) and LM. Coherence in left-right LM and in the right ES-LM increased significantly in the gamma band in the Control group with no increase in the NCLBP group. CONCLUSIONS Our findings indicated that compared to people with NCLBP, the sEMG signals of lumbar muscles of people without NCLBP were more regular and less complex during the 90s-BST.
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Affiliation(s)
- Anke Hua
- Department of Sports Science, Zhejiang University, Hangzhou, China
| | - Jingyuan Bai
- Department of Sports Science, Zhejiang University, Hangzhou, China
| | - Zengming Hao
- Department of Rehabilitation Medicine, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yi Yang
- Department of Sports Science, Zhejiang University, Hangzhou, China
| | | | - Jian Wang
- Department of Sports Science, Zhejiang University, Hangzhou, China; Center for Psychological Science, Zhejiang University, Hangzhou, China.
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2
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Lu P, Hanson NJ, Wen L, Guo F, Tian X. Transcranial Direct Current Stimulation Enhances Muscle Strength of Non-dominant Knee in Healthy Young Males. Front Physiol 2022; 12:788719. [PMID: 34987418 PMCID: PMC8721010 DOI: 10.3389/fphys.2021.788719] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 11/11/2021] [Indexed: 11/25/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) has been applied in training and competition, but its effects on physical performance remain largely unknown. This study aimed to observe the effect of tDCS on muscular strength and knee activation. Nineteen healthy young men were subjected to 20 min of real stimulation (2 mA) and sham stimulation (0 mA) over the primary motor cortex (M1) bilaterally on different days. The maximal voluntary contraction (MVC) of the knee extensors and flexors, and surface electromyography (sEMG) of the rectus femoris (RF) and biceps femoris (BF) were recorded before, immediately after, and 30 min after stimulation. MVC, rate of force development (RFD), and sEMG activity were analyzed before and after each condition. MVC of the non-dominant leg extensor and flexor was significantly higher immediately after real stimulation and 30 min after stimulation than before, and MVC of the non-dominant leg flexor was significantly higher 30 min after real stimulation than that after sham stimulation (P < 0.05). The RFD of the non-dominant leg extensor and flexor immediately after real stimulation was significantly higher than before stimulation, and the RFD of the non-dominant leg extensor immediately after real stimulation and 30 min after stimulation was significantly higher than that of sham stimulation (P < 0.05). EMG analysis showed the root mean square amplitude and mean power frequency (MPF) of the non-dominant BF and RF were significantly higher immediately after real stimulation and 30 min after stimulation than before stimulation, and the MPF of the non-dominant BF EMG was significantly higher 30 min after real stimulation than that after sham stimulation (P < 0.05). Bilateral tDCS of the M1 can significantly improve the muscle strength and explosive force of the non-dominant knee extensor and flexor, which might result from increased recruitment of motor units. This effect can last until 30 min after stimulation, but there is no significant effect on the dominant knee.
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Affiliation(s)
- Panpan Lu
- Department of Sports, Nanchang Institute of Technology, Nanchang, China
| | - Nicholas J Hanson
- Department of Human Performance and Health Education, College of Human Development and Education, Western Michigan University, Kalamazoo, MI, United States
| | - Lin Wen
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Feng Guo
- College of Human Kinesiology, Shenyang Sport University, Shenyang, China
| | - Xiaoyu Tian
- School of Physical Education, Hainan Normal University, Haikou, China
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3
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Casolo A, Del Vecchio A, Balshaw TG, Maeo S, Lanza MB, Felici F, Folland JP, Farina D. Behavior of motor units during submaximal isometric contractions in chronically strength-trained individuals. J Appl Physiol (1985) 2021; 131:1584-1598. [PMID: 34617822 DOI: 10.1152/japplphysiol.00192.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neural and morphological adaptations combine to underpin the enhanced muscle strength following prolonged exposure to strength training, although their relative importance remains unclear. We investigated the contribution of motor unit (MU) behavior and muscle size to submaximal force production in chronically strength-trained athletes (ST) versus untrained controls (UT). Sixteen ST (age: 22.9 ± 3.5 yr; training experience: 5.9 ± 3.5 yr) and 14 UT (age: 20.4 ± 2.3 yr) performed maximal voluntary isometric force (MViF) and ramp contractions (at 15%, 35%, 50%, and 70% MViF) with elbow flexors, whilst high-density surface electromyography (HDsEMG) was recorded from the biceps brachii (BB). Recruitment thresholds (RTs) and discharge rates (DRs) of MUs identified from the submaximal contractions were assessed. The neural drive-to-muscle gain was estimated from the relation between changes in force (ΔFORCE, i.e. muscle output) relative to changes in MU DR (ΔDR, i.e. neural input). BB maximum anatomical cross-sectional area (ACSAMAX) was also assessed by MRI. MViF (+64.8% vs. UT, P < 0.001) and BB ACSAMAX (+71.9%, P < 0.001) were higher in ST. Absolute MU RT was higher in ST (+62.6%, P < 0.001), but occurred at similar normalized forces. MU DR did not differ between groups at the same normalized forces. The absolute slope of the ΔFORCE - ΔDR relationship was higher in ST (+66.9%, P = 0.002), whereas it did not differ for normalized values. We observed similar MU behavior between ST athletes and UT controls. The greater absolute force-generating capacity of ST for the same neural input demonstrates that morphological, rather than neural, factors are the predominant mechanism for their enhanced force generation during submaximal efforts.NEW & NOTEWORTHY In this study, we observed that recruitment strategies and discharge characteristics of large populations of motor units identified from biceps brachii of strength-trained athletes were similar to those observed in untrained individuals during submaximal force tasks. We also found that for the same neural input, strength-trained athletes are able to produce greater absolute muscle forces (i.e., neural drive-to-muscle gain). This demonstrates that morphological factors are the predominant mechanism for the enhanced force generation during submaximal efforts.
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Affiliation(s)
- Andrea Casolo
- Department of Bioengineering, Imperial College London, London, United Kingdom.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Alessandro Del Vecchio
- Department Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Thomas G Balshaw
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom.,Versus Arthritis Centre for Sport, Exercise and Osteoarthritis Research, Loughborough University, Leicestershire, United Kingdom
| | - Sumiaki Maeo
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom.,College of Sport and Health Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Marcel Bahia Lanza
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom.,Department of Physical Therapy and Rehabilitation Science, University of Maryland, Baltimore, Maryland
| | - Francesco Felici
- Department of Movement, Human and Health Sciences, University of Rome 'Foro Italico', Rome, Italy
| | - Jonathan P Folland
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom.,Versus Arthritis Centre for Sport, Exercise and Osteoarthritis Research, Loughborough University, Leicestershire, United Kingdom
| | - Dario Farina
- Department of Bioengineering, Imperial College London, London, United Kingdom
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4
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Morris SJ, Oliver JL, Pedley JS, Haff GG, Lloyd RS. Taking A Long-Term Approach to the Development of Weightlifting Ability in Young Athletes. Strength Cond J 2020. [DOI: 10.1519/ssc.0000000000000608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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5
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Rampichini S, Vieira TM, Castiglioni P, Merati G. Complexity Analysis of Surface Electromyography for Assessing the Myoelectric Manifestation of Muscle Fatigue: A Review. ENTROPY (BASEL, SWITZERLAND) 2020; 22:E529. [PMID: 33286301 PMCID: PMC7517022 DOI: 10.3390/e22050529] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/30/2020] [Accepted: 05/02/2020] [Indexed: 01/13/2023]
Abstract
The surface electromyography (sEMG) records the electrical activity of muscle fibers during contraction: one of its uses is to assess changes taking place within muscles in the course of a fatiguing contraction to provide insights into our understanding of muscle fatigue in training protocols and rehabilitation medicine. Until recently, these myoelectric manifestations of muscle fatigue (MMF) have been assessed essentially by linear sEMG analyses. However, sEMG shows a complex behavior, due to many concurrent factors. Therefore, in the last years, complexity-based methods have been tentatively applied to the sEMG signal to better individuate the MMF onset during sustained contractions. In this review, after describing concisely the traditional linear methods employed to assess MMF we present the complexity methods used for sEMG analysis based on an extensive literature search. We show that some of these indices, like those derived from recurrence plots, from entropy or fractal analysis, can detect MMF efficiently. However, we also show that more work remains to be done to compare the complexity indices in terms of reliability and sensibility; to optimize the choice of embedding dimension, time delay and threshold distance in reconstructing the phase space; and to elucidate the relationship between complexity estimators and the physiologic phenomena underlying the onset of MMF in exercising muscles.
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Affiliation(s)
- Susanna Rampichini
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, 20133 Milan, Italy; (S.R.); (G.M.)
| | - Taian Martins Vieira
- Laboratorio di Ingegneria del Sistema Neuromuscolare (LISiN), Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, 10129 Turin, Italy
- PoliToBIOMed Lab, Politecnico di Torino, 10129 Turin, Italy
| | | | - Giampiero Merati
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, 20133 Milan, Italy; (S.R.); (G.M.)
- IRCCS Fondazione Don Carlo Gnocchi, 20148 Milan, Italy;
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6
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Giannasi LC, Politti F, Dutra MTS, Tenguan VLS, Silva GRC, Mancilha GP, Silva DBD, Oliveira LVF, Oliveira CS, Amorim JBO, Salgado MAC, Gomes MF. Intra-Day and Inter-Day Reliability of Measurements of the electromyographic signal on masseter and temporal muscles in patients with Down syndrome. Sci Rep 2020; 10:7477. [PMID: 32366926 PMCID: PMC7198527 DOI: 10.1038/s41598-020-63963-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 04/01/2020] [Indexed: 11/24/2022] Open
Abstract
The aim of the present study was to evaluate intra-day (test) and inter-day (re-test) reliability of surface electromyography (sEMG) signals of the masseter and temporal muscles in patients with Down syndrome (DS). We determined the reliability of sEMG variables in 33 patients with DS. EMG signals were recorded at rest as well as during maximum voluntary clenching and maximum habitual intercuspation (MHI). The signals were analyzed considering the amplitude in the root mean square (RMS), mean frequency (MNF), median frequency (MDF) and approximate entropy (ApEn). The intraclass correlation (ICC2,1) for the three trials recorded during MHI in the two sessions (test and retest) revealed excellent intra-session and inter-session reliability (ICC2,1 = 0.76 to 0.97) for all sEMG variables and muscles. In the rest position, excellent reliability was found for RMS and ApEn (ICC2,1 = 0.75 to 1.00) and good to excellent reliability was found for MDF and MNF (ICC2,1 = 0.64 to 0.93). The intra-session (test) and inter-session (re-test) analyses demonstrated the reliability of nonlinear sEMG variables of the masticatory muscles in adults with Down Syndrome.
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Affiliation(s)
- Lilian Chrystiane Giannasi
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil. .,Centro Universitário de Anápolis - UniEvangélica, São Paulo, Brazil.
| | | | - Marignês T S Dutra
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil
| | - Vera L S Tenguan
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil
| | - Gabriela R C Silva
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil
| | - Gabriela P Mancilha
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil
| | - Daniel Batista da Silva
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil
| | | | | | - Jose B O Amorim
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil
| | - Miguel Angel Castillo Salgado
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil
| | - Mônica F Gomes
- Center of Biosciences Applied to Patients with Special Health Care Needs (CEBAPE), Institute of Science and Technology, São José dos Campos Campus, São Paulo State University-UNESP, São Paulo, SP, Brazil
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7
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Beretta-Piccoli M, Cescon C, Barbero M, Villiger M, Clijsen R, Kool J, Kesselring J, Bansi J. Upper and lower limb performance fatigability in people with multiple sclerosis investigated through surface electromyography: a pilot study. Physiol Meas 2020; 41:025002. [PMID: 31972554 DOI: 10.1088/1361-6579/ab6f54] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Fatigue experienced by people with multiple sclerosis (pwMS) is multidimensional, consisting of different components, such as perceived, physical and cognitive fatigue and performance fatigability. At present, there is no gold standard to assess performance fatigability in pwMS; therefore, we aimed to determine whether, during a fatiguing task, average rectified value (ARV), mean frequency of the power spectrum (MNF), muscle fiber conduction velocity (CV) and fractal dimension (FD) of surface electromyography (sEMG) may be used as indirect indices of performance fatigability. Moreover, we analyzed whether a three-week rehabilitation program impacts on performance fatigability in pwMS, and whether a relationship between sEMG parameters and trait levels of perceived fatigability, before and after rehabilitation, does exist. APPROACH Twenty-one pwMS performed a 20% maximal voluntary contraction (MVC) of 1 min, and afterwards a 60% MVC held until exhaustion. sEMG signals were detected from the biceps brachii, vastus medialis and vastus lateralis. Performance fatigability was determined at entry to (t 0) and discharge from (t 1) rehabilitation. Perceived fatigability was measured at t 0 and t 2, one month after rehabilitation. MAIN RESULTS ARV, MNF, CV and FD rates of change showed significant changes at t 0 and t 1 (p < 0.05) during the high-level contraction in the BB, but rather limited in the vastii muscles. Moreover, rehabilitation did not induce any reductions in either perceived or performance fatigability. No significant correlations between ARV, MNF, CV and FD rates of change during the 60% MVC and perceived fatigability, at t 0 and t 2, were found. SIGNIFICANCE Our findings suggest that the sEMG parameters are useful for indirectly assessing performance fatigability in pwMS during sub-maximal fatiguing contractions, particularly in the biceps brachii.
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Affiliation(s)
- Matteo Beretta-Piccoli
- Rehabilitation Research Laboratory 2rLab, Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Manno/Landquart, Switzerland. Author to whom any correspondence should be addressed
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8
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Del Vecchio A, Negro F, Falla D, Bazzucchi I, Farina D, Felici F. Higher muscle fiber conduction velocity and early rate of torque development in chronically strength-trained individuals. J Appl Physiol (1985) 2018; 125:1218-1226. [DOI: 10.1152/japplphysiol.00025.2018] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Strength-trained individuals (ST) develop greater levels of force compared with untrained subjects. These differences are partly of neural origin and can be explained by training-induced changes in the neural drive to the muscles. In the present study we hypothesize a greater rate of torque development (RTD) and faster recruitment of motor units with greater muscle fiber conduction velocity (MFCV) in ST compared with a control cohort. MFCV was assessed during maximal voluntary isometric explosive contractions of the elbow flexors in eight ST and eight control individuals. MFCV was estimated from high-density surface electromyogram recordings (128 electrodes) in intervals of 50 ms starting from the onset of the electromyogram. RTD and MFCV were computed and normalized to their maximal voluntary torque (MVT) values. The explosive torque of the ST was greater than in the control group in all time intervals analyzed ( P < 0.001). The absolute MFCV values were also greater for the ST than for controls at all time intervals ( P < 0.001). ST also achieved greater normalized RTD in the first 50 ms of contraction [887.6 (152) vs. 568.5 (148.66)%MVT/s, mean (SD), P < 0.001] and normalized MFCV before the rise in force compared with controls. We have shown for the first time that ST can recruit motor units with greater MFCV in a shorter amount of time compared with untrained subjects during maximal voluntary isometric explosive contractions. NEW & NOTEWORTHY Strength-trained individuals show neuromuscular adaptations. These adaptations have been partly related to changes in the neural drive to the muscles. Here, we show for the first time that during the initial phase of a maximal isometric explosive contraction, strength-trained individuals achieve higher levels of force and recruit motor units with greater conduction velocities.
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Affiliation(s)
- A. Del Vecchio
- Department of Movement, Human and Health Sciences, University of Rome “Foro Italico,” Rome, Italy
- Neuromechanics and Rehabilitation Technology Group, Department of Bioengineering, Imperial College London, London, United Kingdom
| | - F. Negro
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - D. Falla
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - I. Bazzucchi
- Department of Movement, Human and Health Sciences, University of Rome “Foro Italico,” Rome, Italy
| | - D. Farina
- Neuromechanics and Rehabilitation Technology Group, Department of Bioengineering, Imperial College London, London, United Kingdom
| | - F. Felici
- Department of Movement, Human and Health Sciences, University of Rome “Foro Italico,” Rome, Italy
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9
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Pourmoghaddam A, Dettmer M, Malanka SJK, Veverka M, O'Connor DP, Paloski WH, Layne CS. Assessing multiple muscle activation during squat movements with different loading conditions - an EMG study. BIOMED ENG-BIOMED TE 2018; 63:413-420. [PMID: 28672728 DOI: 10.1515/bmt-2016-0226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 04/26/2017] [Indexed: 11/15/2022]
Abstract
Surface electromyography (EMG) is a valuable tool in clinical diagnostics and research related to human neuromotor control. Non-linear analysis of EMG data can help with detection of subtle changes of control due to changes of external or internal constraints during motor tasks. However, non-linear analysis is complex and results may be difficult to interpret, particularly in clinical environments. We developed a non-linear analysis tool (SYNERGOS) that evaluates multiple muscle activation (MMA) features and provides a single value for description of activation characteristics. To investigate the responsiveness of SYNERGOS to kinetic changes during cyclic movements, 13 healthy young adults performed squat movements under different loading conditions (100%-120% of body weight). We processed EMG data to generate SYNERGOS indices and used two-way repeated measures ANOVA to determine changes of MMA in response to loading conditions during movement. SYNERGOS values were significantly different for each loading condition. We concluded that the algorithm is sensitive to kinetic changes during cyclic movements, which may have implications for applications in a variety of experimental and diagnostic settings.
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Affiliation(s)
- Amir Pourmoghaddam
- Memorial Bone and Joint Research Foundation, 10496 Katy Freeway, Suite 101 Houston, TX77043,USA.,Center for Neuromotor and Biomechanics Research (CNBR), Health and Human Performance Department (HHP), University of Houston, 3875 Holman St. Rm 104 Garrison, Houston, TX 77204,USA
| | - Marius Dettmer
- Center for Neuromotor and Biomechanics Research (CNBR), Health and Human Performance Department (HHP), University of Houston, 3875 Holman St. Rm 104 Garrison, Houston, TX 77204,USA.,Director of Research, Memorial Bone and Joint Research Foundation, 10496 Katy Freeway, Suite 101, Houston, TX 77043,USA, Phone: 1 (346) 571-7466
| | - Stefany J K Malanka
- Memorial Bone and Joint Research Foundation, 10496 Katy Freeway, Suite 101 Houston, TX77043,USA
| | - Mitchell Veverka
- Memorial Bone and Joint Research Foundation, 10496 Katy Freeway, Suite 101 Houston, TX77043,USA
| | - Daniel P O'Connor
- Center for Neuromotor and Biomechanics Research (CNBR), Health and Human Performance Department (HHP), University of Houston, 3875 Holman St. Rm 104 Garrison, Houston, TX 77204,USA
| | - William H Paloski
- Center for Neuromotor and Biomechanics Research (CNBR), Health and Human Performance Department (HHP), University of Houston, 3875 Holman St. Rm 104 Garrison, Houston, TX 77204,USA
| | - Charles S Layne
- Center for Neuromotor and Biomechanics Research (CNBR), Health and Human Performance Department (HHP), University of Houston, 3875 Holman St. Rm 104 Garrison, Houston, TX 77204,USA
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10
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Relationship between Isometric Muscle Force and Fractal Dimension of Surface Electromyogram. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5373846. [PMID: 29736393 PMCID: PMC5875057 DOI: 10.1155/2018/5373846] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/01/2018] [Accepted: 02/11/2018] [Indexed: 11/17/2022]
Abstract
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.
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11
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Bauer C, Rast F, Ernst M, Meichtry A, Kool J, Rissanen S, Suni J, Kankaanpää M. The effect of muscle fatigue and low back pain on lumbar movement variability and complexity. J Electromyogr Kinesiol 2017; 33:94-102. [DOI: 10.1016/j.jelekin.2017.02.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 01/20/2017] [Accepted: 02/09/2017] [Indexed: 11/17/2022] Open
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Davidson CM, De Vito G, Lowery MM. Effect of oral glucose supplementation on surface EMG during fatiguing dynamic exercise. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:3498-3502. [PMID: 28269052 DOI: 10.1109/embc.2016.7591482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The aim of this study was to examine the effect of oral glucose supplementation on the surface electromyographic (sEMG) signal recorded during a dynamic, fatiguing exercise protocol. Five healthy subjects participated in the study. Blood glucose concentration and sEMG signals from five upper leg muscles were recorded during a cycling exercise performed at 70% VO2peak until task failure, on two separate occasions. Glucose was consumed at 15 minute intervals throughout one trial. The median frequency of the sEMG was observed to increase progressively throughout the exercise, with a greater increase in the with glucose condition. This is in direct contrast to the typical decrease in median frequency known to occur during a fatiguing isometric contraction. The result may indicate an increase in Na+ - K+ - AT Pase activity during fatiguing dynamic exercise resulting in an increase in muscle fiber membrane excitability due to membrane hyperpolarization.
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13
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Pourmoghaddam A, Dettmer M, O'Connor DP, Paloski WH, Layne CS. Measuring multiple neuromuscular activation using EMG - a generalizability analysis. BIOMED ENG-BIOMED TE 2016; 61:595-605. [PMID: 26684346 DOI: 10.1515/bmt-2015-0037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 11/09/2015] [Indexed: 11/15/2022]
Abstract
Analysis of electromyography (EMG) data has been shown to be valuable in biomedical and clinical research. However, most analysis tools do not consider the non-linearity of EMG data or the synergistic effects of multiple neuromuscular activities. The SYNERGOS algorithm was developed to assess a single index based on non-linear analysis of multiple neuromuscular activation (MNA) of different muscles. This index has shown promising results in Parkinsonian gait, but it was yet to be explored whether the SYNERGOS index is generalizable. In this study, we evaluated generalizability of the SYNERGOS index over the course of several trials and over separate days with different walking speeds. Ten healthy adults aged from 18 to 40 years walked on a treadmill on two different days, while EMG data was collected from the upper and lower right leg. SYNERGOS indices were obtained and a generalizability analysis was conducted. The algorithm detected changes in MNA in response to altering gait speed and depicted a high generalizability coefficient ( ρ^2 ${\hat \rho ^2}$ ) of 0.823 with a standard error of 5.117 with nominal inter-trial or inter-day effects. We concluded SYNERGOS may be a valuable tool in EMG analysis due to its generalizability and its sensitivity to task modifications and associated neuromotor changes.
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Meigal A, Fomina E. Electromyographic evaluation of countermeasures during the terrestrial simulation of interplanetary spaceflight in Mars500 project. ACTA ACUST UNITED AC 2015; 23:11-8. [PMID: 26857518 DOI: 10.1016/j.pathophys.2015.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 10/16/2015] [Accepted: 10/18/2015] [Indexed: 10/22/2022]
Abstract
The efficiency of six countermeasures (CM) for muscle atrophy was compared over 520 days of confinement during the terrestrial simulation of round space flight to Mars using surface electromyography (sEMG). Three of CM were cyclic exercises (a motor-driven and leg-driven treadmill, cycle ergometer), resistive exercises (the multifunctional dynamometer for space-MDS, and expanders), and vibration platform. Each of CM was applied for each crew member (n=6) once over the experiment, for 70 days in a row, in prescribed order. sEMG was collected during the "force step test" in which the subject voluntarily produced pressure by lower limb, with minimal force increment. The mean frequency (MNF) and average amplitude of sEMG were analyzed. The MNF of sEMG decreased from 104.3±4.2 to 95.3±2.9Hz (P<0.05) in the soleus muscle after 70 days of exercising on the leg-driven treadmill and after 35 days-on vibration platform. It can be caused by earlier (10-250ms) recruitment of the soleus in respect with the medial gastronemius on the leg-driven treadmill, while on the motor-driven treadmill synergists activated synchronously. In other lower leg muscles, MNF decreased from 180 to 200 to 165-180Hz after 70 days of resistive exercises on the MDS device. CM caused no effect on sEMG amplitude. In conclusion, (1) the leg-driven treadmill, the MDS and vibration platform significantly depressed MNF of sEMG of lower extremity muscles; (2) the leg-driven treadmill and vibration platform specifically affected the soleus muscle. Therefore, these CM can be recommended for a more extensive use on ISS board.
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Affiliation(s)
- A Meigal
- Institute of Advanced Biomedical Technologies, Petrozavodsk State University, Petrozavodsk, Russian Federation.
| | - E Fomina
- State Scientific Center of Russian Federation Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russian Federation
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15
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Madeleine P, Hansen EA, Samani A. Linear and nonlinear analyses of multi-channel mechanomyographic recordings reveal heterogeneous activation of wrist extensors in presence of delayed onset muscle soreness. Med Eng Phys 2014; 36:1656-64. [DOI: 10.1016/j.medengphy.2014.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 08/21/2014] [Accepted: 09/07/2014] [Indexed: 11/16/2022]
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16
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Giannasi LC, Matsui MY, Politti F, F Batista SR, Caldas BF, Amorim JBO, de Oliveira LVF, Oliveira CS, Gomes MF. Test–retest reliability of electromyographic variables of masseter and temporal muscles in patients with cerebral palsy. Arch Oral Biol 2014; 59:1352-8. [DOI: 10.1016/j.archoralbio.2014.08.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 07/16/2014] [Accepted: 08/18/2014] [Indexed: 10/24/2022]
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17
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González-Izal M, Malanda A, Gorostiaga E, Izquierdo M. Electromyographic models to assess muscle fatigue. J Electromyogr Kinesiol 2012; 22:501-12. [DOI: 10.1016/j.jelekin.2012.02.019] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 02/24/2012] [Accepted: 02/24/2012] [Indexed: 11/24/2022] Open
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18
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Uzun S, Pourmoghaddam A, Hieronymus M, Thrasher TA. Evaluation of muscle fatigue of wheelchair basketball players with spinal cord injury using recurrence quantification analysis of surface EMG. Eur J Appl Physiol 2012; 112:3847-57. [PMID: 22395284 DOI: 10.1007/s00421-012-2358-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 02/14/2012] [Indexed: 11/26/2022]
Abstract
Wheelchair basketball is the most popular exercise activity among individuals with spinal cord injury (SCI). The purpose of this study was to investigate muscular endurance and fatigue in wheelchair basketball athletes with SCI using surface electromyography (SEMG) and maximal torque values. SEMG characteristics of 10 wheelchair basketball players (WBP) were compared to 13 able-bodied basketball players and 12 sedentary able-bodied subjects. Participants performed sustained isometric elbow flexion at 50% maximal voluntary contraction until exhaustion. Elbow flexion torque and SEMG signals were recorded from three elbow flexor muscles: biceps brachii longus, biceps brachii brevis and brachioradialis. SEMG signals were clustered into 0.5-s epochs with 50% overlap. Root mean square (RMS) and median frequency (MDF) of SEMG signals were calculated for each muscle and epoch as traditional fatigue monitoring. Recurrence quantification analysis was used to extract the percentage of determinism (%DET) of SEMG signals. The slope of the %DET for basketball players and WBP showed slower increase with time than the sedentary able-bodied control group for three different elbow flexor muscles, while no difference was observed for the slope of the %DET between basketball and WBP. This result indicated that the athletes are less fatigable during the task effort than the nonathletes. Normalized MDF slope decay exhibited similar results between the groups as %DET, while the slope of the normalized RMS failed to show any significant differences among the groups (p > 0.05). MDF and %DET could be useful for the evaluation of muscle fatigue in wheelchair basketball training. No conclusions about special training for WBP could be determined.
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Affiliation(s)
- S Uzun
- School of Physical Education and Sport, Marmara University, Istanbul, Turkey.
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Kipp K, Harris C, Sabick MB. Lower extremity biomechanics during weightlifting exercise vary across joint and load. J Strength Cond Res 2011; 25:1229-34. [PMID: 21240030 DOI: 10.1519/jsc.0b013e3181da780b] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this study was to determine the effect of load on lower extremity biomechanics during the pull phase of the clean. Kinematic and kinetic data of the 3 joints of the lower extremity were collected while participants performed multiple sets of cleans at 3 percentages: 65, 75, and 85% of 1 repetition maximum (1RM). General linear models with repeated measures were used to assess the influence of load on angular velocities, net torques, powers, and rates of torque development at the ankle, knee, and hip joint. The results suggest that the biomechanical demands required from the lower extremities change with the lifted load and to an extent depend on the respective joint. Most notably, the hip and knee extended significantly faster than the ankle independent of load, whereas the hip and ankle generally produced significantly higher torques than the knee did. Torque, rate of torque development (RTD), and power were maximimal at 85% of 1RM for the ankle joint and at 75% of 1RM for the knee joint. Torque and RTD at the hip were maximal at loads >75% of 1RM. This study provides important novel information about the mechanical demands of a weightlifting exercise and should be heeded in the design of resistance training programs.
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Affiliation(s)
- Kristof Kipp
- Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, Michigan, USA.
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20
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Rathleff M, Samani A, Olesen C, Kersting U, Madeleine P. Inverse relationship between the complexity of midfoot kinematics and muscle activation in patients with medial tibial stress syndrome. J Electromyogr Kinesiol 2011; 21:638-44. [DOI: 10.1016/j.jelekin.2011.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 03/04/2011] [Accepted: 03/04/2011] [Indexed: 10/18/2022] Open
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Reliability of EMG determinism to detect changes in motor unit synchrony and coherence during submaximal contraction. J Neurosci Methods 2011; 196:238-46. [PMID: 21236299 DOI: 10.1016/j.jneumeth.2011.01.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 12/09/2010] [Accepted: 01/05/2011] [Indexed: 11/23/2022]
Abstract
The determinism (DET) is a parameter used in nonlinear analysis to quantify the occurrence of recurrent patterns in a signal. Applied to the electromyographic activity (EMG), DET has been proposed as an index of motor unit synchrony in human. We have recently shown that the amount of motor unit synchronous firings above chance level was enhanced with stronger submaximal muscle contraction. Using these data, we aimed at determining if (1) EMG DET and motor unit synchrony varied in the same way and (2) EMG DET was more specifically related to the degree of oscillatory coupling between motor unit discharges. Cross-correlation and coherence analyses were applied to the discharges of 30 motor unit pairs tested at various force levels to assess the amount of synchronous impulses and the strength of oscillatory coupling in the time and frequency domains, respectively. Recurrent quantification analysis was applied to EMG activity to extract its DET. Overall, changes in EMG DET were poorly explained by changes in motor unit synchronous impulse probability (6%) and frequency (5%), and by changes in motor unit coherence in the 6-12Hz (5%) and 25-40Hz (8%) bands. Moreover, the comparison of the data obtained at the weakest and the strongest contraction levels tested with each motor unit pair showed that EMG DET remained unaltered with stronger contraction despite the occurrence of consistent changes in motor unit synchrony in both time and frequency domains. This speaks strongly against the reliability of DET in evaluating changes in motor unit synchronization during submaximal muscle contraction.
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22
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Hartmann H, Bob A, Wirth K, Schmidtbleicher D. Effects of different periodization models on rate of force development and power ability of the upper extremity. J Strength Cond Res 2010; 23:1921-32. [PMID: 19855316 DOI: 10.1519/jsc.0b013e3181b73c69] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of our study was to compare the effects of 2 different periodization models on strength and power variables under dynamic and static conditions in the bench press. Participants of the experimental groups were male sport students experienced in weight training (age: 23.98 +/- 3.14 yr). Subjects were tested for the 1 repetition maximum (1RM) in the bench press, maximal movement velocity (Vmax) in the bench press throw (16.9 kg), maximal voluntary contraction (MVC), and maximal rate of force development (MRFD) in 90 degrees elbow and shoulder angle in the isometric bench press. According to their 1RM, subjects were parallelized and assigned to 1 of either 2 training groups: strength-power periodization (SPP, n = 13) or daily undulating periodization (DUP, n = 14). Subjects trained for 14 weeks, 3 days per week. In the strength-power sessions, both groups were instructed to lift the weight as explosively as possible. In addition, a control group (n = 13) was used for comparison. One repetition maximum and Vmax improved significantly through training (p <or= 0.05), with no significant changes in MVC and MRFD. Experimental groups showed no significant group differences in any variable. The results indicate that, in short-term training using previously trained subjects, no differences in 1RM and power are seen between DUP and SPP. As used in our undulating regime, additional training in strength endurance could lead to exhaustion effects and furthermore does not provide an adequate training stimulus for power because of its low training intensity. In spite of this, according to the present findings, it has no negative effect on the application of a neural stimulus that is needed for a strength-power session if adequate regeneration time between workouts is guaranteed.
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Affiliation(s)
- Hagen Hartmann
- Institute of Sport Sciences, Goethe University, Frankfurt/Main, Germany.
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23
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Dideriksen JL, Falla D, Bækgaard M, Mogensen ML, Steimle KL, Farina D. Comparison between the degree of motor unit short-term synchronization and recurrence quantification analysis of the surface EMG in two human muscles. Clin Neurophysiol 2009; 120:2086-2092. [PMID: 19828371 DOI: 10.1016/j.clinph.2009.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 09/07/2009] [Accepted: 09/17/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To verify if non-linear recurrence analysis of the surface EMG is a suitable tool for assessing motor unit short-term synchronization. METHODS Surface and intramuscular EMG signals were recorded from the abductor digiti minimi and vastus medialis muscles of 12 and 10 healthy men, respectively, during isometric contractions. In the abductor digiti minimi, EMG signals were additionally recorded after a contraction sustained for 1min at 50% of the maximal force. In both muscles, percent of determinism (%DET) was estimated from the surface EMG and common input strength (CIS) index was computed from motor unit recordings. RESULTS For both muscles, CIS did not correlate with %DET (abductor digiti minimi: R(2)=0.11, P=0.12; vastus medialis: R(2)=0.04, P=0.56). Although the values of CIS for the vastus medialis were lower than those of the abductor digiti minimi (P<0.001), the %DET values did not differ between the two muscles (71.6+/-5.5% vs 66.9+/-8.7%; P=0.12). CONCLUSION The variable %DET extracted from the surface EMG is a poor indicator of the degree of motor unit short-term synchronization. SIGNIFICANCE The study provides a systematic evaluation of a technique previously proposed for the estimation of a clinically relevant characteristic of motor unit behavior.
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Affiliation(s)
- J L Dideriksen
- Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - D Falla
- Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - M Bækgaard
- Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - M L Mogensen
- Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - K L Steimle
- Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - D Farina
- Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
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24
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Christie A, Greig Inglis J, Kamen G, Gabriel DA. Relationships between surface EMG variables and motor unit firing rates. Eur J Appl Physiol 2009; 107:177-85. [PMID: 19544067 DOI: 10.1007/s00421-009-1113-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2009] [Indexed: 12/13/2022]
Abstract
Although surface electromyography (sEMG) is a widely used electrophysiological technique, its physiological interpretation remains somewhat controversial. This study examined the relationship between motor unit firing rates (MUFR) and the root mean square (RMS) amplitude and mean power frequency (MPF) of the sEMG signal in the biceps brachii. Eleven subjects performed maximal isometric elbow flexion while indwelling and sEMG recordings were obtained from the biceps. The RMS amplitude and MPF of the surface signal, and the mean MUFR from the indwelling signal, were calculated over 500 ms epochs. Group means showed a strong MUFR-RMS amplitude relationship (r (2) = 0.91), but a weak MUFR-MPF relationship (r (2) = 0.20). Using all trials, the MUFR-RMS amplitude (r (2) = 0.19) and MUFR-MPF (r (2) = 0.0037) relationships were much weaker. Within individual subjects, the MUFR-RMS amplitude (mean r (2) = 0.13 +/- 0.17) and the MUFR-MPF (mean r (2) = 0.040 +/- 0.041) relationships were also weak. These results suggest that MUFR cannot be predicted from the characteristics of the sEMG signal.
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Affiliation(s)
- Anita Christie
- Department of Kinesiology, University of Massachusetts, Amherst, MA, USA
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25
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Cifrek M, Medved V, Tonković S, Ostojić S. Surface EMG based muscle fatigue evaluation in biomechanics. Clin Biomech (Bristol, Avon) 2009; 24:327-40. [PMID: 19285766 DOI: 10.1016/j.clinbiomech.2009.01.010] [Citation(s) in RCA: 370] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Accepted: 01/28/2009] [Indexed: 02/07/2023]
Abstract
In the last three decades it has become quite common to evaluate local muscle fatigue by means of surface electromyographic (sEMG) signal processing. A large number of studies have been performed yielding signal-based quantitative criteria of fatigue in primarily static but also in dynamic tasks. The non-invasive nature of this approach has been particularly appealing in areas like ergonomics and occupational biomechanics, to name just the most prominent ones. However, a correct appreciation of the findings concerned can only be obtained by judging both the scientific value and practical utility of methods while appreciating the corresponding advantages and limitations. The aim of this paper is to serve as a state of the art summary of this issue. The paper gives an overview of classical and modern signal processing methods and techniques from the standpoint of applicability to sEMG signals in fatigue-inducing situations relevant to the broad field of biomechanics. Time domain, frequency domain, time-frequency and time-scale representations, and other methods such as fractal analysis and recurrence quantification analysis are described succinctly and are illustrated with their biomechanical applications, research or clinical alike. Examples from the authors' own work are incorporated where appropriate. The future of this methodology is projected by estimating those methods that have the greatest chance to be routinely used as reliable muscle fatigue measures.
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Affiliation(s)
- Mario Cifrek
- Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000 Zagreb, Croatia.
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26
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Morana C, Ramdani S, Perrey S, Varray A. Recurrence quantification analysis of surface electromyographic signal: sensitivity to potentiation and neuromuscular fatigue. J Neurosci Methods 2008; 177:73-9. [PMID: 18955082 DOI: 10.1016/j.jneumeth.2008.09.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2008] [Revised: 09/17/2008] [Accepted: 09/26/2008] [Indexed: 10/21/2022]
Abstract
This study aimed to assess the capacity of recurrence quantification analysis (RQA) to detect potentiation and to determine the fatigue components to which RQA is sensitive. Fifteen men were divided in two groups [8 endurance-trained athletes (END) and 7 power-trained athletes (POW)]. They performed a 10-min intermittent (5s contraction, 5s rest) knee extension exercise at 50% of their maximal voluntary isometric contraction. Muscular fatigue and potentiation were evaluated with neurostimulation technique. Mechanical (peak torque, Pt) and electrophysiological (M-wave) responses following electrical stimulation of the femoral nerve were measured at rest and every 10s throughout exercise. Vastus lateralis muscle activity (root mean square, RMS) was recorded during each contraction, and RMS was normalized to M-wave area (RMS/M). During contraction, muscle activity was analyzed with RQA to obtain the percentage of determinism (%Det). At the beginning of exercise, a significant Pt increase (+52%, P<0.001) was observed in both groups, indicating potentiation. At this time, %Det remained constant in both groups, indicating that RQA did not detect potentiation. Thereafter, Pt decreased in POW from 5min 30s of exercise (-30%, P<0.001), reflecting impairment in excitation-contraction coupling, and %Det increased from 3min 30s (P<0.01). In END, Pt remained high and %Det was unchanged. These two results indicated that RQA detected the peripheral component of fatigue. Conversely, RQA did not detect central adaptation to fatigue since %Det remained constant when a significant increase in RMS/M (P<0.01) appeared in END.
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Affiliation(s)
- Claire Morana
- EA 2991 Motor Efficiency and Deficiency Laboratory, University of Montpellier 1, Faculty of Sport Sciences, 700 Avenue du Pic Saint Loup, 34090 Montpellier, France.
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Motor unit synchronization in FDI and biceps brachii muscles of strength-trained males. J Electromyogr Kinesiol 2008; 19:800-9. [PMID: 18691906 DOI: 10.1016/j.jelekin.2008.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 06/10/2008] [Accepted: 06/10/2008] [Indexed: 11/22/2022] Open
Abstract
Motor unit (MU) synchronization is the simultaneous or near-simultaneous firing of two MUs which occurs more often than would be expected by chance. The present study sought to investigate the effects of exercise training, muscle group, and force level, by comparing the magnitude of synchronization in the biceps brachii (BB) and first dorsal interosseous (FDI) muscles of untrained and strength-trained college-aged males at two force levels, 30% of maximal voluntary contraction (MVC) and 80% MVC. MU action potentials were recorded directly via an intramuscular needle electrode. The magnitude of synchronization was assessed using previously-reported synchronization indices: k', E, and CIS. Synchronization was significantly higher in the FDI than in the BB. Greater synchronization was observed in the strength-trained group with CIS, but not with E or k'. Also, synchronization was significantly greater at 80% MVC than at 30% MVC with E, but only moderately greater with CIS and there was no force difference with k'. Synchronization prevalence was found to be greater in the BB (80.1%) than in the FDI (71.5%). Thus, although the evidence is a bit equivocal, it appears that MU synchronization is greater at higher forces, and greater in strength-trained individuals than in untrained subjects.
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Meigal AI, Rissanen S, Tarvainen MP, Karjalainen PA, Iudina-Vassel IA, Airaksinen O, Kankaanpää M. Novel parameters of surface EMG in patients with Parkinson's disease and healthy young and old controls. J Electromyogr Kinesiol 2008; 19:e206-13. [PMID: 18407522 DOI: 10.1016/j.jelekin.2008.02.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 02/27/2008] [Accepted: 02/27/2008] [Indexed: 11/19/2022] Open
Abstract
The aim of this study was to evaluate a variety of traditional and novel surface electromyography (SEMG) characteristics of biceps brachii muscle in patients with Parkinson's disease (PD) and compare the results with the healthy old and young control subjects. Furthermore, the aim was to define the optimal biceps brachii loading level that would most likely differentiate patients from controls. The results indicated that such nonlinear SEMG parameters as %Recurrence, %Determinism and SEMG distribution kurtosis, correlation dimension and sample entropy were significantly different between the PD patients and healthy controls. These novel nonlinear parameters, unlike traditional spectral or amplitude parameters, correlated with the Unified Parkinson's Disease Rating Scale (UPDRS) and finger tapping scores. The most significant between group differences were found in the loading condition where no additional weights were applied in isometric elbow flexion. No major difference of SEMG characteristics was detected between old and young control subjects. In conclusion, the novel SEMG parameters can differentiate the patients with PD from healthy control subjects and these parameters may have potential in the assessment of the severity of PD.
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Affiliation(s)
- A I Meigal
- Petrozavodsk State University, 185910 Petrozavodsk, Russian Federation
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29
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Maejima H, Murase A, Sunahori H, Kanetada Y, Otani T, Yoshimura O, Tobimatsu Y. Neural Adjustment in the Activation of the Lower Leg Muscles through Daily Physical Exercises in Community-Based Elderly Persons. TOHOKU J EXP MED 2007; 211:141-9. [PMID: 17287598 DOI: 10.1620/tjem.211.141] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Reflecting the rapidly aging population, community-based interventions in the form of physical exercise have been introduced to promote the health of elderly persons. Many investigation studies have focused on muscle strength in the lower leg as a potent indicator of the effect of physical exercises. The objective of this study was to assess the effect of long-term daily exercises on neural command in lower leg muscle activations. Twenty-six community-based elderly persons (13 men and 13 women; 69.8 +/- 0.5 years old) participated in this study. Daily exercise was comprised of walking for more than 30 min, stretching, muscle strengthening and balance exercise, and was continued for three months. Muscle strength and surface electromyography of the tibia anterior, rectus femoris, and biceps femoris were measured in maximum isometric voluntary contraction both before and after the intervention. The mean frequency of the firing of motor units was calculated based on fast Fourier transformation of the electromyography. As the results of the intervention, muscle strength increased significantly only in biceps femoris, whereas the mean frequency of motor units decreased significantly in every muscle, indicating that motor unit firing in lower frequency efficiently induces the same or greater strength compared with before the intervention. Thus, synchronization of motor units compensates for the lower frequency of motor unit firing to maintain muscular strength. In conclusion, long-term physical exercises in the elderly can modulate the neural adjustment of lower leg muscles to promote efficient output of muscle strength.
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Affiliation(s)
- Hiroshi Maejima
- Division of Physical Therapy and Occupational Therapy Sciences, Graduate School of Health Sciences, Hiroshima University, Japan.
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30
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Del Santo F, Gelli F, Mazzocchio R, Rossi A. Recurrence quantification analysis of surface EMG detects changes in motor unit synchronization induced by recurrent inhibition. Exp Brain Res 2006; 178:308-15. [PMID: 17053906 DOI: 10.1007/s00221-006-0734-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Accepted: 09/22/2006] [Indexed: 10/24/2022]
Abstract
The systemic injection of L-Acetylcarnitine (L-Ac) induces a reversible increase in recurrent inhibition. In addition, L-Ac potentiation of recurrent inhibition has been found to increase the synchronous activity of single motor units, as detected by traditional linear analysis in the time domain. This result has been recently confirmed using a nonlinear method based on the analysis of embedded determinism (%DET) extracted from the surface EMG. The present study aimed at testing the general applicability of RQA methodology, as a viable tool for assessing motor unit synchronization, by extending the analysis of surface EMG, as revealed by changes in %DET induced by L-Ac, to many upper and lower limb muscles and to muscles that are not easily studied by needle electrodes, such as the orbicularis oculi. Subjects performed brief periods of tonic contractions, alternated to periods of rests to avoid muscle fatigue. Pharmacological enhancement of recurrent inhibition was obtained by a short-lasting intravenous injection of L-Ac. Control experiments were performed replacing L-Ac injection with saline injection. The average %DET showed a significant increase during L-Ac injection in the deltoid, biceps brachii, extensor carpi radialis, while no effect was observed in the opponens pollicis and abductor digiti minimi for the upper limb muscles. Similarly, the average %DET showed a significant increase during L-Ac injection in the quadriceps, soleus, and tibialis anterior, while no effect was observed in the abductor hallucis for the lower limb muscles. RQA of orbicularis oculi muscle activity showed no increase in %DET during L-Ac injection in analogy to what found in the intrinsic muscles of the hand and foot, known to be devoid of recurrent inhibition. The presence or absence of drug-induced increase in motor unit synchronization agrees with the known distribution of recurrent inhibition in the various motor nuclei. The overall significance of these findings is the potential application of RQA methodology as a reliable and independent tool for generally assessing motor unit synchronization from surface EMG under strictly controlled experimental condition.
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Affiliation(s)
- F Del Santo
- Section of Clinical Neurophysiology, Department of Neurological and Behavioural Sciences, University of Siena, Viale Bracci, Siena, Italy
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31
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Abstract
Physical exercise promotes a wide spectrum of short and long term responses of different organs and apparatuses. While skeletal muscle adaptations to the different training regimens are conveniently known and described, the neural counterpart of them are still to be described in full. In this paper, an attempt is made to fix the state of the art and particularly to point out the contribution derived from the analysis of the surface electromyographic signal. In this paper, some examples of sEMG applications in exercise physiology will be reported from studies where only strictly non-invasive techniques (or of very limited invasiveness) were applied. A consistent amount of space in this lecture will be dedicated to the advanced analysis of sEMG using non linear tools.
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Affiliation(s)
- Francesco Felici
- Department of Human Movement and Sport Sciences, Istituto Universitario di Scienze Motorie, Largo Lauro De Bosis 6, 00194 Roma, Italy.
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32
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Del Santo F, Gelli F, Schmied A, Vedel JP, Rossi A, Mazzocchio R. Motor unit synchronous firing as revealed by determinism of surface myoelectric signal. J Neurosci Methods 2006; 155:116-21. [PMID: 16472869 DOI: 10.1016/j.jneumeth.2006.01.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Revised: 12/05/2005] [Accepted: 01/08/2006] [Indexed: 11/15/2022]
Abstract
Information on motor strategies can be extracted from the surface electromyogram (EMG) by non-linear methods. The percentage of determinism (%DET) obtained from recurrence quantification analysis (RQA) may be a sensitive variable to detect synchronous motor unit behaviour. The purpose of the present study was to validate this methodology by comparing it with an established technique estimating the degree of synchronization of pairs of voluntary activated motor units from the correlation of their firing in the time-domain. Single motor unit activity was recorded in extensor carpi radialis (ECR) muscle by pairs of tungsten microelectrodes inserted into the muscle belly. Cross-correlation analysis was performed in order to determine synchronization peak area by computing synchronous impulse probability. Surface EMG activity was recorded in parallel by electrodes placed over the skin of the same muscle and %DET was used as a measure of synchronous activity. The %DET appeared to be a valid measure of synchronization yielding results comparable to those obtained with cross-correlation analysis. Increases in %DET (t = 64.59, P < 0.0001) highly correlated (r2 = 0.70, P = 0.0013) with pharmacologically induced increases in the synchronization activity of pairs of ECR motor units (t = 8.71, P < 0.0001). RQA may be used as an alternative methodology for testing synchronous motor unit behaviour from surface EMG under physiological and pathological conditions.
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Affiliation(s)
- F Del Santo
- Sezione di Neurofisiologia Clinica, Dipartimento di Scienze Neurologiche e del Comportamento, Università di Siena, Italy
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33
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Fattorini L, Felici F, Filligoi GC, Traballesi M, Farina D. Influence of high motor unit synchronization levels on non-linear and spectral variables of the surface EMG. J Neurosci Methods 2004; 143:133-9. [PMID: 15814145 DOI: 10.1016/j.jneumeth.2004.09.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2004] [Revised: 09/27/2004] [Accepted: 09/29/2004] [Indexed: 11/30/2022]
Abstract
The aim of this study was to investigate the influence of high degrees of motor unit synchronization on surface EMG variables extracted by linear and non-linear analysis techniques. For this purpose, spectral and recurrent quantification analysis (RQA) were applied to both simulated and experimental EMG signals. Synthetic surface EMG signals were generated with a model of volume conductor comprising muscle, fat, and skin tissues. The synchronization was quantified by the percent of discharges of each motor unit synchronized with discharges of other motor units. The simulated signals presented degrees of synchronization in the range 0-80% (10% increments) and three mean values of motor unit conduction velocity distribution (3, 4 and 5 m/s). Experimental signals were collected from the first dorsal interosseous muscle of five patients with Parkinson disease during 10s of rest and 10s of isometric voluntary contraction at 50% of the maximal force. Mean power spectral frequency (MNF) and percent of determinism (%DET) of the surface EMG were computed from the simulated and experimental signals. In the simulated signals, %DET was linearly related to the level of synchronization in the entire range considered while MNF was sensitive to changes in synchronization in a smaller range (0-20%), outside which it levelled off. The experimental results indicated that %DET was significantly higher in the resting condition (with presence of tremor; mean +/- S.E., 85.4 +/- 0.8%) than during the voluntary contraction (which partly suppressed tremor; 60.0 +/- 2.3%; P < 0.01). On the contrary, MNF did not depend on the condition (114.3 +/- 1.5 Hz and 118.0 +/- 0.8 Hz for the resting and voluntary contraction, respectively), confirming the simulation results. Overall, these results indicated that linear and non-linear analyses of the surface EMG may have different sensitivities to the underlying physiological mechanisms in specific conditions, thus their joint use provides a more complete view of the muscle status than spectral analysis only.
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Affiliation(s)
- L Fattorini
- Dip. Fisiologia Umana e Farmacologia, Università di Roma La Sapienza, Italy
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34
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Abstract
This brief review examines some of the methods used to infer central control strategies from surface electromyogram (EMG) recordings. Among the many uses of the surface EMG in studying the neural control of movement, the review critically evaluates only some of the applications. The focus is on the relations between global features of the surface EMG and the underlying physiological processes. Because direct measurements of motor unit activation are not available and many factors can influence the signal, these relations are frequently misinterpreted. These errors are compounded by the counterintuitive effects that some system parameters can have on the EMG signal. The phenomenon of crosstalk is used as an example of these problems. The review describes the limitations of techniques used to infer the level of muscle activation, the type of motor unit recruited, the upper limit of motor unit recruitment, the average discharge rate, and the degree of synchronization between motor units. Although the global surface EMG is a useful measure of muscle activation and assessment, there are limits to the information that can be extracted from this signal.
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Affiliation(s)
- Dario Farina
- Dipartimento di Elettronica, Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino 10129, Italy.
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35
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Liu Y, Kankaanpää M, Zbilut JP, Webber CL. EMG recurrence quantifications in dynamic exercise. BIOLOGICAL CYBERNETICS 2004; 90:337-348. [PMID: 15221394 DOI: 10.1007/s00422-004-0474-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2003] [Accepted: 02/25/2004] [Indexed: 05/24/2023]
Abstract
This study was designed to evaluate the suitability of nonlinear recurrence quantification analysis (RQA) in assessing electromyograph (EMG) signals during dynamic exercise. RQA has been proven to be effective in analyzing nonstationary signals. The subject group consisted of 19 male patients diagnosed with low back pain. EMG signals were recorded from left and right paraspinal muscles during isoinertial exercise both before and after 12 weeks of regimented physical therapy. Autorecurrence analysis was performed between the left and right EMG signals individually, and cross-recurrence analysis was performed on the left-right EMG pairs. Spectral analysis of the EMG signals was employed as an independent, objective measure of fatigue. Increase in the RQA variable % determinism during the 90-s dynamic tests was found to be a good marker for fatigue. Before physical therapy, this nonlinear marker revealed simultaneous increases in motor unit recruitment within each pool and between left and right pools. After physical therapy, the motor unit recruitment was less within and between pools, indicative of increased fatigue resistance. Finally, fatigue resistance (less increase in % determinism) correlated well with subjective scores of pain relief. Taken together, these latter results indicate that recurrence analysis may be useful in charting the efficacy of a specific exercise therapy program in reducing low back pain by elevating the fatigue threshold.
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Affiliation(s)
- Yiwei Liu
- Department of Physiology, Loyola University Medical Center, 2160, South First Avenue, Maywood, IL 60153-3304, USA
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Sbriccoli P, Bazzucchi I, Rosponi A, Bernardi M, De Vito G, Felici F. Amplitude and spectral characteristics of biceps Brachii sEMG depend upon speed of isometric force generation. J Electromyogr Kinesiol 2003; 13:139-47. [PMID: 12586519 DOI: 10.1016/s1050-6411(02)00098-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
In the present study the influence of speed of contraction on the interplay between recruitment and firing rate of motor units (MUs) was assessed. The surface electromyographic (sEMG) signal was recorded in nine healthy subjects from the right biceps brachii using a linear electrode array during ramp isometric contractions (from 0 to 100% of the maximal voluntary force, MVC) at 5, 10, and 20% MVC s(-1) (ramp phase), followed by 10 s of sustained MVC (hold phase). The median frequency (MDF), Root Mean Square (RMS) and conduction velocity (CV) of sEMG, were computed on adjacent epochs covering a force range of 5% MVC each. Full motor unit recruitment (FMUR) point was assessed as the force level at which MDF reached its maximum value; the MDF decay during the hold phase was taken as an index of localized muscle fatigue. At 5% MVC s(-1), FMUR was reached at 52.3% MVC. At 10%MVC s(-1) FMUR was achieved at 58% MVC; while at 20% MVC s(-1) FMUR point was located at 77% MVC, being statistically different from 5 and 10% MVCs(-1) ramps (p<0.05). The MDF decay was steeper at higher speed. CV modifications mirrored those reported for MDF. The RMS increased in a curvilinear fashion and the maximum value was always attained during the hold phase. Our findings suggest that MU recruitment strategies are significantly related to the speed of contraction even in a single muscle.
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Affiliation(s)
- P Sbriccoli
- University Institute of Motor Sciences, Piazza Lauro De Bosis 15, I-00194 Rome, Italy
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37
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Farina D, Fattorini L, Felici F, Filligoi G. Nonlinear surface EMG analysis to detect changes of motor unit conduction velocity and synchronization. J Appl Physiol (1985) 2002; 93:1753-63. [PMID: 12381763 DOI: 10.1152/japplphysiol.00314.2002] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Amplitude and frequency content of the surface electromyographic (EMG) signal reflect central and peripheral modifications of the neuromuscular system. Classic surface EMG spectral variables applied to assess muscle functions are the centroid and median power spectral frequencies. More recently, nonlinear tools have been introduced to analyze the surface EMG; among them, the recurrence quantification analysis (RQA) was shown to be particularly promising for the detection of muscle status changes. The purpose of this work was to analyze the effect of motor unit short-term synchronization and conduction velocity (CV) on EMG spectral variables and two variables extracted by RQA, the percentage of recurrence (%Rec) and determinism (%Det). The study was performed on the basis of a simulation model, which allowed changing the degree of synchronization and mean CV of a number of motor units, and of an experimental investigation of the surface EMG signal properties detected during high-force-level isometric fatiguing contractions of the biceps brachii muscle. Simulations and experimental results were largely in agreement and show that 1) spectral variables, %Rec, and %Det are influenced by CV and degree of synchronization; 2) spectral variables are highly correlated with %Det (R = -0.95 in the simulations and -0.78 and -0.75 for the initial values and normalized slopes, respectively, in the experimental signals), and thus the information they provide on muscle properties is basically the same; and 3) variations of %Det and %Rec in response to changes in muscle properties are significantly larger than the variations of spectral variables. This study validates RQA as a means for fatigue assessment with potential advantages (such as the higher sensitivity to changes of muscle status) with respect to the classic spectral analysis.
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Affiliation(s)
- Dario Farina
- Centro di Bioingegneria, Dipartimento di Elettronica, Politecnico di Torino, Torino 10129, Italy.
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