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Association of Muscle Strength With Muscle Thickness and Motor Unit Firing Pattern of Vastus Lateralis Muscle in Youth Athletes. Int J Sports Physiol Perform 2022; 17:1725-1731. [DOI: 10.1123/ijspp.2022-0094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 08/02/2022] [Accepted: 08/25/2022] [Indexed: 11/15/2022]
Abstract
Purpose: Contributions of neural and muscular factors to muscle strength change with growth, but such changes remain unclear in young populations. This study aimed to clarify the association between muscle strength and neural and muscular factors in youth athletes. Methods: Maximal voluntary contraction (MVC) during isometric knee extension, the motor unit firing rate (MUFR), and muscle thickness (MT) of the vastus lateralis were measured in 70 youth male soccer players (mean [SD]; chronological age = 16.3 [0.6] y, peak height velocity age = 13.1 [1.0] y). MUFR and MT were measured with high-density surface electromyography and ultrasonography, respectively. Results: For MUFR and MT, correlations with MVC were calculated and the values of different MVC groups were compared. A significant correlation between MVC and MT (r = .49, P < .01) was noted, but not MUFR (r = .03, P > .05). There was also no significant correlation between MT and MUFR (r = −.33, P > .05). In addition, comparison among groups (higher-/middle-/lower-strength groups) revealed that MT in the lower-strength group was significantly lower than in middle-and higher-strength groups (P < .01). Conclusion: In youth athletes, muscle strength is associated with muscular factors, rather than neural factors, and muscular and neural factors may independently contribute to muscle strength.
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Yılmaz AK, Vural M, Özdal M, Kabadayı M. A comparative study of the acute effects of knee brace vs. kinesiotape on selected isokinetic strength variables of the knee muscles. ISOKINET EXERC SCI 2021. [DOI: 10.3233/ies-200175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: Different methods of treatment for preventing knee injuries, enhancing knee strength and minimising post-injury risks have been explored. Among these methods, Kinesio tape (KT) and knee braces (KB) are commonly used. OBJECTIVE : To investigate the acute effects of KT and KB on isokinetic knee strength parameters. METHODS: A total of 15 healthy sedentary male subjects voluntarily participated in the study. Concentric isokinetic knee extension (EX) and flexion (FLX) strength were measured at three sessions: 1. Baseline 2. with KT (’KT’) 3. with KB (’KB’). Tests were performed at 60, 180 and 240∘/s. Peak moment (PM), Hamstring/Quadriceps ratio (HQR), and joint angle at peak moment (JAPM) were measured. RESULTS: ‘KT’ and ‘KB’ were associated with increase in PMEX, PMFLX, HQR at 60 and 240∘/s (p< 0.05) and increased JAPMEX. No significant difference was observed at 180∘/s (p> 0.05). CONCLUSION: In healthy individuals, ‘I’ shape KT and KB positively affect EX and FLX strengths and HQR, especially at low angular velocity.
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Affiliation(s)
- Ali Kerim Yılmaz
- Ondokuz Mayıs University Performance Laboratory, Faculty of Sport Sciences, Ondokuz Mayıs University, Samsun, Turkey
| | - Mehmet Vural
- Gaziantep University Performance Laboratory, Faculty of Sport Sciences, Gaziantep University, Gaziantep, Turkey
| | - Mustafa Özdal
- Gaziantep University Performance Laboratory, Faculty of Sport Sciences, Gaziantep University, Gaziantep, Turkey
| | - Menderes Kabadayı
- Ondokuz Mayıs University Performance Laboratory, Faculty of Sport Sciences, Ondokuz Mayıs University, Samsun, Turkey
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Hussain J, Sundaraj K, Subramaniam ID. Cognitive stress changes the attributes of the three heads of the triceps brachii during muscle fatigue. PLoS One 2020; 15:e0228089. [PMID: 31999750 PMCID: PMC6992167 DOI: 10.1371/journal.pone.0228089] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 01/07/2020] [Indexed: 02/03/2023] Open
Abstract
INTRODUCTION Cognitive stress (CS) changes the peripheral attributes of a muscle, but its effect on multi-head muscles has not been investigated. The objective of the current research was to investigate the impact of CS on the three heads of the triceps brachii (TB) muscle. METHODS Twenty-five young and healthy university students performed a triceps push-down exercise at 45% one repetition maximum (1RM) with and without CS until task failure, and the rate of fatigue (ROF), endurance time (ET) and number of repetitions (NR) for both exercises were analyzed. In addition, the first and last six repetitions of each exercise were considered non-fatiguing (NF) and fatiguing (Fa), respectively, and the root mean square (RMS), mean power frequency (MPF) and median frequency (MDF) for each exercise repetition were evaluated. RESULTS The lateral and long head showed significant differences (P<0.05) in the ROF between the two exercises, and all the heads showed significant (P<0.05) differences in the RMS between the two exercises under NF conditions. Only the long head showed a significant difference (P<0.05) in the MPF and MDF between the two exercises. CS increases the ET (24.74%) and NR (27%) of the exercise. The three heads showed significant differences (P<0.05) in the RMS, MPF and MDF under all exercise conditions. CONCLUSION A lower ROF was obtained with CS. In addition, the RMS was found to be better approximator of CS, whereas MPF and MDF were more resistant to the effect of CS. The results showed that the three heads worked independently under all conditions, and the non-synergist and synergist head pairs showed similar behavior under Fa conditions. The findings from this study provide additional insights regarding the functioning of each TB head.
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Affiliation(s)
- Jawad Hussain
- Centre for Telecommunication Research & Innovation, Fakulti Kejuruteraan Elektronik & Kejuruteraan Komputer, Universiti Teknikal Malaysia Melaka, Durian Tunggal, Malaysia
| | - Kenneth Sundaraj
- Centre for Telecommunication Research & Innovation, Fakulti Kejuruteraan Elektronik & Kejuruteraan Komputer, Universiti Teknikal Malaysia Melaka, Durian Tunggal, Malaysia
| | - Indra Devi Subramaniam
- Centre for Technopreneurship Development, Pusat Bahasa & Pembangunan Insan, Universiti Teknikal Malaysia Melaka, Durian Tunggal, Malaysia
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Anders JPV, Keller JL, Smith CM, Hill EC, Neltner TJ, Housh TJ, Schmidt RJ, Johnson GO. Performance fatigability and neuromuscular responses for bilateral versus unilateral leg extensions in women. J Electromyogr Kinesiol 2019; 50:102367. [PMID: 31711012 DOI: 10.1016/j.jelekin.2019.102367] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/18/2019] [Accepted: 10/29/2019] [Indexed: 01/04/2023] Open
Abstract
The purpose of this study was to compare isokinetic peak torque and the patterns of responses for electromyographic (EMG) and mechanomyographic (MMG), amplitude (AMP) and mean power frequency (MPF) for bilateral (BL) versus unilateral (UL), maximal, isokinetic leg extensions. Eleven recreationally trained women (Mean ± SD: age 22.9 ± 0.9 yrs; body mass 60.5 ± 10.1 kg; height 167.2 ± 6.4 cm) performed 50 maximal, BL and UL isokinetic leg extensions at 60° s-1 on separate days. Electromyographic and MMG signals from the vastus lateralis of the nondominant leg were recorded. Five separate 2 (Condition [BL and UL]) × 10 (Repetitions [5-50]) repeated measures ANOVAs were performed to examine normalized EMG AMP, EMG MPF, MMG AMP, MMG MPF, and isokinetic torque. The results indicated no significant interactions or main effects for EMG AMP and MMG AMP. There were significant interactions for normalized isokinetic peak torque (p < 0.001, η2p = 0.493) and MMG MPF (p = 0.003, η2p = 0.234). For EMG MPF, there was no significant interaction, but significant main effects for Condition (p = 0.003, η2p = 0.607) and Repetitions (p < 0.001, η2p = 0.805). The current findings demonstrated greater performance fatigability for UL than BL leg extensions. Both modalities exhibited similar patterns of neuromuscular responses that were consistent with the Muscular Wisdom hypothesis.
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Affiliation(s)
- John Paul V Anders
- Department of Nutrition and Human Sciences, University of Nebraska- Lincoln, Lincoln, NE 68510, USA.
| | - Joshua L Keller
- Department of Nutrition and Human Sciences, University of Nebraska- Lincoln, Lincoln, NE 68510, USA
| | - Cory M Smith
- College of Health Sciences, Kinesiology, University of Texas at El Paso, El Paso, TX 39968, USA
| | - Ethan C Hill
- School of Kinesiology and Physical Therapy, Division of Kinesiology University of Central Florida, Orlando, FL 32816, USA
| | - Tyler J Neltner
- Department of Nutrition and Human Sciences, University of Nebraska- Lincoln, Lincoln, NE 68510, USA
| | - Terry J Housh
- Department of Nutrition and Human Sciences, University of Nebraska- Lincoln, Lincoln, NE 68510, USA
| | - Richard J Schmidt
- Department of Nutrition and Human Sciences, University of Nebraska- Lincoln, Lincoln, NE 68510, USA
| | - Glen O Johnson
- Department of Nutrition and Human Sciences, University of Nebraska- Lincoln, Lincoln, NE 68510, USA
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Imbalanced Corticospinal and Reticulospinal Contributions to Spasticity in Humans with Spinal Cord Injury. J Neurosci 2019; 39:7872-7881. [PMID: 31413076 DOI: 10.1523/jneurosci.1106-19.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/22/2019] [Accepted: 07/25/2019] [Indexed: 02/04/2023] Open
Abstract
Damage to the corticospinal and reticulospinal tract has been associated with spasticity in humans with upper motor neuron lesions. We hypothesized that these descending motor pathways distinctly contribute to the control of a spastic muscle in humans with incomplete spinal cord injury (SCI). To test this hypothesis, we examined motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation over the leg representation of the primary motor cortex, maximal voluntary contractions (MVCs), and the StartReact response (shortening in reaction time evoked by a startling stimulus) in the quadriceps femoris muscle in male and females with and without incomplete SCI. A total of 66.7% of the SCI participants showed symptoms of spasticity, whereas the other 33.3% showed no or low levels of spasticity. We found that participants with spasticity had smaller MEPs and MVCs and larger StartReact compared with participants with no or low spasticity and control subjects. These results were consistently present in spastic subjects but not in the other populations. Clinical scores of spasticity were negatively correlated with MEP-max and MVC values and positively correlated with shortening in reaction time. These findings provide evidence for lesser corticospinal and larger reticulospinal influences to spastic muscles in humans with SCI and suggest that these imbalanced contributions are important for motor recovery.SIGNIFICANCE STATEMENT Although spasticity is one of the most common symptoms manifested in humans with spinal cord injury (SCI) to date, its mechanisms of action remain poorly understood. We provide evidence, for the first time, of imbalanced contributions of the corticospinal and reticulospinal tract to control a spastic muscle in humans with chronic incomplete SCI. We found that participants with SCI with spasticity showed small corticospinal responses and maximal voluntary contractions and larger reticulospinal gain compared with participants with no or low spasticity and control subjects. These results were consistently present in spastic subjects but not in the other populations. We showed that imbalanced corticospinal and reticulospinal tract contributions are more pronounced in participants with chronic incomplete SCI with lesser recovery.
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Anders JPV, Smith CM, Keller JL, Hill EC, Housh TJ, Schmidt RJ, Johnson GO. Inter- and Intra-Individual Differences in EMG and MMG during Maximal, Bilateral, Dynamic Leg Extensions. Sports (Basel) 2019; 7:sports7070175. [PMID: 31323817 PMCID: PMC6681382 DOI: 10.3390/sports7070175] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/04/2019] [Accepted: 07/16/2019] [Indexed: 02/07/2023] Open
Abstract
The purpose of this study was to compare the composite, inter-individual, and intra-individual differences in the patterns of responses for electromyographic (EMG) and mechanomyographic (MMG) amplitude (AMP) and mean power frequency (MPF) during fatiguing, maximal, bilateral, and isokinetic leg extension muscle actions. Thirteen recreationally active men (age = 21.7 ± 2.6 years; body mass = 79.8 ± 11.5 kg; height = 174.2 ± 12.7 cm) performed maximal, bilateral leg extensions at 180°·s−1 until the torque values dropped to 50% of peak torque for two consecutive repetitions. The EMG and MMG signals from the vastus lateralis (VL) muscles of both limbs were recorded. Four 2(Leg) × 19(time) repeated measures ANOVAs were conducted to examine mean differences for EMG AMP, EMG MPF, MMG AMP, and MMG MPF between limbs, and polynomial regression analyses were performed to identify the patterns of neuromuscular responses. The results indicated no significant differences between limbs for EMG AMP (p = 0.44), EMG MPF (p = 0.33), MMG AMP (p = 0.89), or MMG MPF (p = 0.52). Polynomial regression analyses demonstrated substantial inter-individual variability. Inferences made regarding the patterns of neuromuscular responses to fatiguing and bilateral muscle actions should be considered on a subject-by-subject basis.
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Affiliation(s)
- John Paul V Anders
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE 68510, USA.
| | - Cory M Smith
- College of Health Sciences, Kinesiology, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Joshua L Keller
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE 68510, USA
| | - Ethan C Hill
- School of Kinesiology & Physical Therapy, Division of Kinesiology, University of Central Florida, Orlando, FL 32816, USA
| | - Terry J Housh
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE 68510, USA
| | - Richard J Schmidt
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE 68510, USA
| | - Glen O Johnson
- Department of Nutrition and Human Sciences, University of Nebraska-Lincoln, Lincoln, NE 68510, USA
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Doğan E, Yilmaz AK, Özdal M, Mayda MH, Yilmaz Ç, Ermi̇ş E. Acute effects of reverse Kinesio Taping on knee muscle strength, fatigue index and H/Q ratio in healthy subjects. ISOKINET EXERC SCI 2019. [DOI: 10.3233/ies-183223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Erol Doğan
- Sport Science Faculty, Ondokuz Mayıs University, Samsun, Turkey
| | | | - Mustafa Özdal
- Department of Physical Education and Sport, Gaziantep University, Gaziantep, Turkey
| | | | - Çoşkun Yilmaz
- Sport Science Faculty, Ondokuz Mayıs University, Samsun, Turkey
| | - Egemen Ermi̇ş
- Sport Science Faculty, Ondokuz Mayıs University, Samsun, Turkey
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Fukuhara S, Oka H. A Simplified Analysis of Real-time Monitoring of Muscle Contraction during Dynamic Exercise Using an MMG/EMG Hybrid Transducer System. ADVANCED BIOMEDICAL ENGINEERING 2019. [DOI: 10.14326/abe.8.185] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Shinichi Fukuhara
- Department of Medical Engineering, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare
| | - Hisao Oka
- Graduate School of Interdisciplinary Science and Engineering of Health Systems, Okayama University
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Reliability of the twitch evoked skeletal muscle electromechanical efficiency: A ratio between tensiomyogram and M-wave amplitudes. J Electromyogr Kinesiol 2017; 37:108-116. [DOI: 10.1016/j.jelekin.2017.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 09/25/2017] [Accepted: 10/11/2017] [Indexed: 12/28/2022] Open
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Vigotsky AD, Beardsley C, Contreras B, Steele J, Ogborn D, Phillips SM. Greater Electromyographic Responses Do Not Imply Greater Motor Unit Recruitment and ‘Hypertrophic Potential’ Cannot Be Inferred. J Strength Cond Res 2017; 31:e1-e4. [DOI: 10.1519/jsc.0000000000001249] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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Smith CM, Housh TJ, Herda TJ, Zuniga JM, Camic CL, Bergstrom HC, Smith DB, Weir JP, Hill EC, Cochrane KC, Jenkins NDM, Schmidt RJ, Johnson GO. Time Course of Changes in Neuromuscular Parameters During Sustained Isometric Muscle Actions. J Strength Cond Res 2016; 30:2697-2702. [PMID: 27658233 DOI: 10.1519/jsc.0000000000001547] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Smith, CM, Housh, TJ, Herda, TJ, Zuniga, JM, Camic, CL, Bergstrom, HC, Smith, DB, Weir, JP, Hill, EC, Cochrane, KC, Jenkins, NDM, Schmidt, RJ, and Johnson, GO. Time course of changes in neuromuscular parameters during sustained isometric muscle actions. J Strength Cond Res 30(10): 2697-2702, 2016-The objective of the present study was to identify the time course of changes in electromyographic (EMG) and mechanomyographic (MMG) time and frequency domain parameters during a sustained isometric muscle action of the leg extensors at 50% maximal voluntary isometric contraction. The EMG and MMG signals were measured from the vastus lateralis of 11 subjects to identify when motor unit activation strategies changed throughout the sustained isometric muscle action. The EMG amplitude (muscle activation) had a positive linear relationship (p = 0.018, r = 0.77) that began to increase at the initiation of the muscle action and continued until task failure. Electromyographic frequency (motor unit action potential conduction velocity) and MMG frequency (global motor unit firing rate) had negative quadratic relationships (p = 0.002, R = 0.99; p = 0.015, R = 0.94) that began to decrease at 30% of the time to exhaustion. The MMG amplitude (motor unit activation) had a cubic relationship (p = 0.001, R = 0.94) that increased from 10 to 30% of the time to exhaustion, then decreased from 40 to 70% of the time to exhaustion, and then markedly increased from 70% to task failure. The time course of changes in the neuromuscular parameters suggested that motor unit activation strategies changed at approximately 30 and 70% of the time to exhaustion during the sustained isometric muscle action. These findings indicate that the time course of changes in neuromuscular responses provide insight into the strategies used to delay the effects of fatigue and are valuable tools for quantifying changes in the fatiguing process during training programs or supplementation research.
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Affiliation(s)
- Cory M Smith
- 1Department of Nutrition and Health Science, University of Nebraska-Lincoln, Lincoln, Nebraska;2Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas;3Department of Exercise Science & Pre-Health Professions, Creighton University, Omaha, Nebraska;4Department of Exercise & Sport Science, University of Wisconsin-La Crosse, La Crosse, Wisconsin;5Department of Kinesiology & Health Promotion, University of Kentucky, Lexington, Kentucky; and6Department of Health and Human Performance, Oklahoma State University-Stillwater, Stillwater, Oklahoma
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Krueger E, Scheeren EM, Nogueira-Neto GN, Button VLDSN, Nohama P. Correlation between spectral and temporal mechanomyography features during functional electrical stimulation. ACTA ACUST UNITED AC 2016. [DOI: 10.1590/2446-4740.02315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Eddy Krueger
- Universidade Tecnológica Federal do Paraná, Brazil; Universidade Estadual de Londrina, Brazil
| | | | | | | | - Percy Nohama
- Universidade Tecnológica Federal do Paraná, Brazil; Pontifícia Universidade Católica do Paraná, Brazil; Universidade Estadual de Campinas, Brazil
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Croce R, Craft A, Miller J, Chamberlin K, Filipovic D. Quadriceps mechano- and electromyographic time-frequency responses during muscular contractions to volitional exhaustion. Muscle Nerve 2016; 53:452-63. [DOI: 10.1002/mus.24764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 06/30/2015] [Accepted: 07/07/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Ronald Croce
- Motor Control and Biomechanics Laboratory; Department of Kinesiology; University of New Hampshire; Durham New Hampshire 03824 USA
| | - Amber Craft
- Motor Control and Biomechanics Laboratory; Department of Kinesiology; University of New Hampshire; Durham New Hampshire 03824 USA
| | - John Miller
- Motor Control and Biomechanics Laboratory; Department of Kinesiology; University of New Hampshire; Durham New Hampshire 03824 USA
| | - Kent Chamberlin
- Department of Electrical and Computer Engineering; University of New Hampshire; Durham New Hampshire USA
| | - David Filipovic
- Department of Electrical and Computer Engineering; University of New Hampshire; Durham New Hampshire USA
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Aspe RR, Swinton PA. Electromyographic and kinetic comparison of the back squat and overhead squat. J Strength Cond Res 2015; 28:2827-36. [PMID: 24662228 DOI: 10.1519/jsc.0000000000000462] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this study was to compare muscle activity and kinetics during the back squat and overhead squat performed at 3 relative intensities (60, 75, and 90% 3 repetition maximum). Fourteen subjects (age, 26 ± 7 years; height, 182.5 ± 13.5 cm; body mass, 90.5 ± 17.5 kg) performed each exercise using a within-subjects crossover design. In addition, a selection of trunk isolation exercises were included to provide additional comparisons. Squats were performed on a force platform with electromyographic activity of the anterior deltoid, rectus abdominis (RA), external oblique (EO), erector spinae (ES), gluteus maximus, vastus lateralis, biceps femoris, and lateral gastrocnemius recorded throughout. The overhead squat demonstrated significantly greater (p ≤ 0.05) activity in the anterior trunk muscles (RA and EO) during the eccentric phase. However, the magnitudes of the differences were relatively small (approximately 2-7%). In contrast, the back squat displayed significantly greater (p ≤ 0.05) activity in the posterior aspect of the trunk ES and all lower-body muscles during the concentric phase. Kinetic comparisons revealed that significantly greater peak force (p ≤ 0.05) was developed during the back squat. Electromyographic comparisons between the trunk isolation exercises and squat variations demonstrated substantially greater anterior trunk activity during the isolation exercises, whereas the highest activity in the posterior aspect of the trunk was obtained during the squats (p ≤ 0.05). The results of the study do not support the hypothesis that the overhead squat provides a substantially greater stimulus for developing the trunk musculature compared with the back squat.
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Affiliation(s)
- Rodrigo R Aspe
- 1School of Sport and Exercise, University of Gloucestershire, Gloucester, England; and 2School of Social and Health Sciences, Robert Gordon University, Aberdeen, Scotland
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Bilgin G, Hindistan IE, Özkaya YG, Köklükaya E, Polat Ö, Çolak ÖH. Determination of Fatigue Following Maximal Loaded Treadmill Exercise by Using Wavelet Packet Transform Analysis and MLPNN from MMG-EMG Data Combinations. J Med Syst 2015; 39:108. [PMID: 26276016 DOI: 10.1007/s10916-015-0304-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 07/27/2015] [Indexed: 11/30/2022]
Abstract
The muscle fatigue can be expressed as decrease in maximal voluntary force generating capacity of the neuromuscular system as a result of peripheral changes at the level of the muscle, and also failure of the central nervous system to drive the motoneurons adequately. In this study, a muscle fatigue detection method based on frequency spectrum of electromyogram (EMG) and mechanomyogram (MMG) has been presented. The EMG and MMG data were obtained from 31 healthy, recreationally active men at the onset, and following exercise. All participants were performed a maximally exercise session in a motor-driven treadmill by using standard Bruce protocol which is the most widely used test to predict functional capacity. The method used in the present study consists of pre-processing, determination of the energy value based on wavelet packet transform, and classification phases. The results of the study demonstrated that changes in the MMG 176-234 Hz and EMG 254-313 Hz bands are critical to determine for muscle fatigue occurred following maximally exercise session. In conclusion, our study revealed that an algorithm with EMG and MMG combination based on frequency spectrum is more effective for the detection of muscle fatigue than EMG or MMG alone.
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Affiliation(s)
- Gürkan Bilgin
- Vocational School of Technical Sciences, Mehmet Akif Ersoy University, Burdur, Turkey
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Zhang S, Fu W, Pan J, Wang L, Xia R, Liu Y. Acute effects of Kinesio taping on muscle strength and fatigue in the forearm of tennis players. J Sci Med Sport 2015; 19:459-64. [PMID: 26229044 DOI: 10.1016/j.jsams.2015.07.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 06/27/2015] [Accepted: 07/09/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To explore the immediate effects of Kinesio taping applied over the wrist extensors and flexors on muscle strength and endurance during isometric and isokinetic muscle actions. DESIGN The study had a single-blinded, placebo control, and randomized design. METHODS Fourteen trained male volunteers were required to complete 5s isometric maximal voluntary contractions and 50 consecutive maximal concentric wrist extension and flexion repetitions at each of two angular speeds (60°/s and 210°/s) in three taping conditions: Kinesio taping (KT), placebo taping (PT), and no taping (NT). RESULTS KT did not improve peak moment, peak power, average power, and total work for wrist extensors and flexors in the isometric and isokinetic contractions. However, KT showed a 13% decrease in work fatigue of the wrist flexors compare to NT (p=0.014) at 60°/s. Furthermore, a 20% decrease was also observed in the rate of decline of moment (k) of the wrist flexors in KT compared to NT (p=0.007), and the k in PT was also significantly lower in magnitude compared to NT (p=0.035). Moreover, there was also a trend in terms of magnitudes for kKT<kPT<kNT in the wrist flexors at 210°/s. CONCLUSIONS Kinesio taping may not be able to modulate strength production in healthy athletes immediately, but does have a significant positive effect on reducing muscle fatigue during repeated concentric muscle actions. Additionally, the potential beneficial effects of placebo taping on muscle endurance should not be ignored either.
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Affiliation(s)
- Shen Zhang
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, China
| | - Weijie Fu
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, China.
| | - Jiahao Pan
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, China
| | - Lin Wang
- Department of Sports Rehabilitation, Shanghai University of Sport, China
| | - Rui Xia
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, China
| | - Yu Liu
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, China.
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Novel insights into skeletal muscle function by mechanomyography: from the laboratory to the field. SPORT SCIENCES FOR HEALTH 2015. [DOI: 10.1007/s11332-015-0219-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Mechanomyographic parameter extraction methods: an appraisal for clinical applications. SENSORS 2014; 14:22940-70. [PMID: 25479326 PMCID: PMC4299047 DOI: 10.3390/s141222940] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/28/2014] [Accepted: 11/04/2014] [Indexed: 11/16/2022]
Abstract
The research conducted in the last three decades has collectively demonstrated that the skeletal muscle performance can be alternatively assessed by mechanomyographic signal (MMG) parameters. Indices of muscle performance, not limited to force, power, work, endurance and the related physiological processes underlying muscle activities during contraction have been evaluated in the light of the signal features. As a non-stationary signal that reflects several distinctive patterns of muscle actions, the illustrations obtained from the literature support the reliability of MMG in the analysis of muscles under voluntary and stimulus evoked contractions. An appraisal of the standard practice including the measurement theories of the methods used to extract parameters of the signal is vital to the application of the signal during experimental and clinical practices, especially in areas where electromyograms are contraindicated or have limited application. As we highlight the underpinning technical guidelines and domains where each method is well-suited, the limitations of the methods are also presented to position the state of the art in MMG parameters extraction, thus providing the theoretical framework for improvement on the current practices to widen the opportunity for new insights and discoveries. Since the signal modality has not been widely deployed due partly to the limited information extractable from the signals when compared with other classical techniques used to assess muscle performance, this survey is particularly relevant to the projected future of MMG applications in the realm of musculoskeletal assessments and in the real time detection of muscle activity.
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Silva CRD, Silva DDO, Ferrari D, Negrão Filho RDF, Alves N, Azevedo FMD. Exploratory study of electromyographic behavior of the vastus medialis and vastus lateralis at neuromuscular fatigue onset. MOTRIZ: REVISTA DE EDUCACAO FISICA 2014. [DOI: 10.1590/s1980-65742014000200012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study aimed to determine and analyze the neuromuscular fatigue onset by median frequency (MDF) and the root mean square (RMS) behavior of an electromyographic signal (EMG). Eighteen healthy men with no prior knee problems initially performed three maximum voluntary isometric contractions (MVIC). After two days of MVIC test, participants performed a fatiguing protocol in which they performed submaximal knee-extension contractions at 20% and 70% MVIC held to exhaustion. The MDF and RMS values from the EMG signals were recorded from the vastus medialis (VM) and the vastus lateralis (VL). Analysis of the MDF and RMS behavior enabled identification of neuromuscular fatigue onset for VM and VL muscles in 20% and 70% loads. Alterations between the VM and VL in the neuromuscular fatigue onset, at 20% and 70% MVIC, were not significant. These findings suggest that the methodology proposal was capable of indicating minute differences sensible to alterations in the EMG signals, allowing identification of the moment when the MDF and the RMS showed significant changes in behavior. The methodology used was also a viable one for describing and identifying the neuromuscular fatigue onset by means of the analysis of EMG signals.
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Ibitoye MO, Hamzaid NA, Zuniga JM, Abdul Wahab AK. Mechanomyography and muscle function assessment: a review of current state and prospects. Clin Biomech (Bristol, Avon) 2014; 29:691-704. [PMID: 24856875 DOI: 10.1016/j.clinbiomech.2014.04.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 02/07/2023]
Abstract
Previous studies have explored to saturation the efficacy of the conventional signal (such as electromyogram) for muscle function assessment and found its clinical impact limited. Increasing demand for reliable muscle function assessment modalities continues to prompt further investigation into other complementary alternatives. Application of mechanomyographic signal to quantify muscle performance has been proposed due to its inherent mechanical nature and ability to assess muscle function non-invasively while preserving muscular neurophysiologic information. Mechanomyogram is gaining accelerated applications in evaluating the properties of muscle under voluntary and evoked muscle contraction with prospects in clinical practices. As a complementary modality and the mechanical counterpart to electromyogram; mechanomyogram has gained significant acceptance in analysis of isometric and dynamic muscle actions. Substantial studies have also documented the effectiveness of mechanomyographic signal to assess muscle performance but none involved comprehensive appraisal of the state of the art applications with highlights on the future prospect and potential integration into the clinical practices. Motivated by the dearth of such critical review, we assessed the literature to investigate its principle of acquisition, current applications, challenges and future directions. Based on our findings, the importance of rigorous scientific and clinical validation of the signal is highlighted. It is also evident that as a robust complement to electromyogram, mechanomyographic signal may possess unprecedented potentials and further investigation will be enlightening.
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Affiliation(s)
- Morufu Olusola Ibitoye
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Biomedical Engineering, Faculty of Engineering and Technology, University of Ilorin, P. M. B. 1515 Ilorin, Nigeria.
| | - Nur Azah Hamzaid
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Jorge M Zuniga
- Department of Exercise Science, Creighton University, 2500 California Plaza, Kiewit Fitness center 228, Omaha, NE 68178, United States.
| | - Ahmad Khairi Abdul Wahab
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
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Mechanomyographic and electromyographic responses during fatiguing eccentric muscle actions of the leg extensors. J Appl Biomech 2013; 30:255-61. [PMID: 24145683 DOI: 10.1123/jab.2013-0178] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of the current study was to examine the patterns of responses for torque, mechanomyographic (MMG) amplitude, MMG frequency, electromyographic (EMG) amplitude, and EMG frequency across 30 repeated maximal eccentric muscle actions of the leg extensors. Eleven moderately trained females performed an eccentric fatigue protocol at 30°/s with MMG and EMG signals recorded from the vastus lateralis. The results indicated there were significant (P<.05) decreases in MMG frequency (linear, r2=.395), EMG frequency (linear, r2=.177), and torque (linear, r2=.570; % decline=9.8±13.3%); increases in MMG amplitude (linear, r2=.783); and no change in EMG amplitude (r2=.003). These findings suggested that the neural strategies used to modulate torque during fatiguing eccentric muscle actions involved de-recruitment of motor units, reduced firing rates, and synchronization. In addition, the decreases in eccentric torque were more closely associated with changes in MMG frequency than EMG frequency. Thus, these findings indicated that MMG frequency, compared with EMG frequency, more accurately tracks fatigue during repeated maximal eccentric muscle actions.
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Mechanomyographic responses for the biceps brachii are unable to track the declines in peak torque during 25, 50, 75, and 100 fatiguing isokinetic muscle actions. J Appl Biomech 2013; 29:769-78. [PMID: 23549437 DOI: 10.1123/jab.29.6.769] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study examined the peak torque and mechanomyographic (MMG) amplitude and mean frequency (MNF) responses during fatiguing isokinetic muscle actions. On four separate occasions, twenty men (mean ± SD age = 23 ± 3 years) performed 25, 50, 75, and 100 repeated maximal concentric isokinetic muscle actions of the dominant forearm flexors. During each muscle action, the MMG signal was detected from the biceps brachii with an accelerometer. The data were examined with linear regression and one-way repeated measures analyses of variance. The results indicated that the mean percent decline in peak torque value for the 25 repetition trial (25.6%) was significantly less than that for the 50 repetition trial (45.2%). Furthermore, the mean linear slope coefficient for the peak torque versus repetition number relationship for the 50 repetition trial was significantly less than that for the 100 repetition trial. There were no mean differences among the trials for the linear slope coefficients and y-intercepts for the MMG amplitude and MNF versus repetition number relationships. When detected with an accelerometer, the linear slope coefficients and y-intercepts for the MMG amplitude and MNF versus repetition number relationships were not sensitive enough to track the decline in muscle function during fatigue.
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Camic CL, Housh TJ, Zuniga JM, Russell Hendrix C, Bergstrom HC, Traylor DA, Schmidt RJ, Johnson GO. Electromyographic and mechanomyographic responses across repeated maximal isometric and concentric muscle actions of the leg extensors. J Electromyogr Kinesiol 2013; 23:342-8. [DOI: 10.1016/j.jelekin.2012.09.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 07/24/2012] [Accepted: 09/27/2012] [Indexed: 11/15/2022] Open
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Fu W, Liu Y, Fang Y. Research Advancements in Humanoid Compression Garments in Sports. INT J ADV ROBOT SYST 2013. [DOI: 10.5772/54560] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The utilization of sport-related compression garments has attracted a great deal of attention from among Sports Science scholars. The function of the garments, such as to maintain muscle functions, reduce sports injuries and improve athletic performance, has been an issue of debate since the beginning of the new century. In this study, a number of methods including a literature review, logical analysis and mathematical statistics, are used to analyse earlier compression garments research, which can be found by searching hardcopy journals and online databases. Among the existing studies, most have tested and confirmed the functions of the garments; however, only a few have mentioned the underlying mechanism. Thus, by using more advanced and appropriate compression materials, future studies into compression garments will be focused on the vibration characteristics of muscles (soft tissues), and especially on their proprioceptive sensation, neuromuscular control, injury prevention and performance enhancement.
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Affiliation(s)
- Weijie Fu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Yu Liu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Ying Fang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
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Silva CRD, Geres BS, Kuriki HU, Negrão Filho RDF, Alves N, Azevedo FMD. Análise da reprodutibilidade de parâmetros no domínio da frequência do sinal EMG utilizados na caracterização da fadiga muscular localizada. MOTRIZ: REVISTA DE EDUCACAO FISICA 2012. [DOI: 10.1590/s1980-65742012000300006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
O objetivo deste estudo foi analisar a reprodutibilidade de parâmetros no domínio da frequência do sinal eletromiográfico (EMG) utilizados na caracterização da fadiga muscular localizada. Quinze sujeitos do sexo masculino foram submetidos a um teste de fadiga baseado na extensão isométrica de joelho, sendo realizados em três momentos distintos com intervalos de sete dias. Para avaliar a reprodutibilidade dos dados entres os testes calculou-se o coeficiente de correlação intraclasse (CCI) para a frequência mediana (Fmed) no tempo total de exercício (FmedT), para a Fmed obtida a cada 10% do tempo de exercício (Fmed10%) e para as potências das bandas de frequência, obtidas da divisão do espectro de potência a cada 20 Hz. Os resultados demonstraram: (1) boa reprodutibilidade para a FmedT; (2) boa reprodutibilidade para a Fmed10%; e (3) maior variação no sinal EMG nas bandas de 20 a 120 Hz, no qual se destacam as bandas de 20-40 Hz e de 40-60 Hz, demonstrando maior sensibilidade ao processo de fadiga muscular. Conclui-se que a Fmed é uma variável que apresenta boa reprodutibilidade e que a análise fragmentada do espectro de potência, por meio das bandas de frequência, demonstrou-se sensível as variações que ocorrem no sinal EMG durante a instalação do processo de fadiga, tendo potencial para se tornar um novo método para a caracterização da fadiga muscular localizada.
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Affiliation(s)
| | | | | | | | - Neri Alves
- Universidade Estadual Paulista, Brasil; Universidade de São Paulo, Brasil
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Variation of force amplitude and its effects on local fatigue. Eur J Appl Physiol 2012; 112:3865-79. [PMID: 22407330 DOI: 10.1007/s00421-012-2375-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 02/28/2012] [Indexed: 11/25/2022]
Abstract
Trends in industry are leaning toward stereotyped jobs with low workloads. Physical variation is an intervention to reduce fatigue and potentially musculoskeletal disorders in such jobs. Controlled laboratory studies have provided some insight into the effectiveness of physical variation, but very few have been devoted to force variation without muscular rest as a component. This study was undertaken to determine multiple physiological responses to five isometric elbow extension protocols with the same mean amplitude (15% maximum voluntary contraction, MVC), cycle time (6 s), and duty cycle (50 %). Sustained (15 %Sus) and intermittent contractions including zero force (0-30 %Int) differed significantly in 19 of 27 response variables. Contractions varying by half the mean force (7.5-22.5 %Int) led to 8 and 7 measured responses that were significantly different from 0-30 %Int and 15 %Sus, respectively. A sinusoidal condition (0-30 %Sine) resulted in 2 variables that were significantly different from 0-30 %Int, and 16 different from 15 %Sus. Finally, ten response variables suggested that varying forces with 1 % as the lower contraction level was significantly less fatiguing than 15 %Sus, while no responses were significantly different from 0-30 %Int. Sustained contractions led to decreased twitch force 24-h post-exercise, whereas recovery was complete within 60 min after intermittent contractions. This suggests that time-varying force may be a useful intervention to reduce local fatigue in workers performing low-load tasks, and also that rest per se did not seem to cause any extraordinary effects beyond those predictable from the force variation amplitude.
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Fu W, Liu Y, Zhang S, Xiong X, Wei S. Effects of local elastic compression on muscle strength, electromyographic, and mechanomyographic responses in the lower extremity. J Electromyogr Kinesiol 2011; 22:44-50. [PMID: 22100152 DOI: 10.1016/j.jelekin.2011.10.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 08/24/2011] [Accepted: 10/15/2011] [Indexed: 12/01/2022] Open
Abstract
The purpose of this study was to investigate the effect of elastic compression on muscle strength, electromyographic (EMG), and mechanomyographic (MMG) responses of quadriceps femoris during isometric and isokinetic contractions. Twelve participants performed 5s isometric maximal voluntary contractions (MVC) and 25 consecutive and maximal isokinetic knee extensions at 60 and 300°/s with no (control, CC), medium (MC), and high (HC) compression applied to the muscle. The EMG and MMG signals were collected simultaneously with muscle isometric and isokinetic strength data. The results showed that the elevated compression did not improve peak torque, peak power, average power, total work, and regression of torque in the isometric and isokinetic contractions. However, the root mean squared value of EMG in both HC and MC significantly decreased compared with CC at 60 and 300°/s (p<0.01). Furthermore, the EMG mean power frequency in HC was significantly higher than that in CC at 60°/s (p<0.05) whereas no significant compression effect was found in the MMG mean power frequency. These findings provide preliminary evidence suggesting that the increase in local compression pressure may effectively increase muscle efficiency and this might be beneficial in reducing muscle fatigue during concentric isokinetic muscle contractions.
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Affiliation(s)
- Weijie Fu
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
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28
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Patrek MF, Kernozek TW, Willson JD, Wright GA, Doberstein ST. Hip-abductor fatigue and single-leg landing mechanics in women athletes. J Athl Train 2011; 46:31-42. [PMID: 21214348 DOI: 10.4085/1062-6050-46.1.31] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Reduced hip-abductor strength and muscle activation may be associated with altered lower extremity mechanics, which are thought to increase the risk for anterior cruciate ligament injury. However, experimental evidence supporting this relationship is limited. OBJECTIVE To examine the changes in single-leg landing mechanics and gluteus medius recruitment that occur after a hip-abductor fatigue protocol. DESIGN Descriptive laboratory study. PATIENTS OR OTHER PARTICIPANTS Twenty physically active women (age = 21.0 ± 1.3 years). INTERVENTION(S) Participants were tested before (prefatigue) and after (postfatigue) a hip-abductor fatigue protocol consisting of repetitive side-lying hip abduction. MAIN OUTCOME MEASURE(S) Outcome measures included sagittal-plane and frontal-plane hip and knee kinematics at initial contact and at 60 milliseconds after initial contact during 5 single-leg landings from a height of 40 cm. Peak hip and knee sagittal-plane and frontal-plane joint moments during this time interval were also analyzed. Measures of gluteus medius activation, including latency, peak amplitude, and integrated signal, were recorded. RESULTS A small (<1°) increase in hip-abduction angle at initial contact and a small (<1°) decrease in knee-abduction (valgus) angle at 60 milliseconds after contact were observed in the postfatigue landing condition. No other kinematic changes were noted for the knee or hip at initial contact or at 60 milliseconds after initial contact. Peak external knee-adduction moment decreased 27% and peak hip adduction moment decreased 24% during the postfatigue landing condition. Gluteus medius activation was delayed after the protocol, but no difference in peak or integrated signal was seen during the landing trials. CONCLUSIONS Changes observed during single-leg landings after hip-abductor fatigue were not generally considered unfavorable to the integrity of the anterior cruciate ligament. Further work may be justified to study the role of hip-abductor activation in protecting the knee during landing.
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Affiliation(s)
- Mary F Patrek
- Department of Exercise and Sport Science, University of Wisconsin-La Crosse, La Crosse, WI 54601, USA
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Miyamoto N, Hirata K, Mitsukawa N, Yanai T, Kawakami Y. Effect of pressure intensity of graduated elastic compression stocking on muscle fatigue following calf-raise exercise. J Electromyogr Kinesiol 2011; 21:249-54. [DOI: 10.1016/j.jelekin.2010.08.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 07/05/2010] [Accepted: 08/14/2010] [Indexed: 11/26/2022] Open
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Santos MCA, Semeghuini TA, Azevedo FMD, Colugnati DB, Negrão Filho RDF, Alves N, Arida RM. Análise da fadiga muscular localizada em atletas e sedentários através de parâmetros de freqüência do sinal eletromiográfico. REV BRAS MED ESPORTE 2008. [DOI: 10.1590/s1517-86922008000600007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Embora a análise no domínio da freqüência do sinal eletromiográfico (EMG) seja empregada na caracterização do processo de fadiga muscular localizada, sua aplicação, especificamente a da freqüência mediana (Fmed), é pouco explorada no âmbito esportivo. O objetivo do presente estudo foi verificar a viabilidade da aplicação do sinal EMG, através de sua análise no domínio da freqüência, como parâmetro para determinação e diferenciação no comportamento da fadiga muscular localizada. Dois grupos de sujeitos, um caracterizado como atletas (n =12) e outro como sedentários (n =12), foram submetidos a análises baseadas em procedimentos executados em três diferentes situações experimentais, todos envolvendo a modalidade de exercício isométrico: i) teste máximo para determinação da contração isométrica voluntária máxima (CIVM); ii) teste de fadiga, sustentado por 35 seg. a 80% da CIVM; iii) teste de recuperação, sustentado por 10 seg. a 80% da CIVM; neste ultimo foi monitorado o comportamento da Fmed nos três primeiros (Fmedi) e três últimos segundos (Fmedf) do sinal EMG no músculo tibial anterior durante o teste de fadiga. Durante os 10 segundos do teste de recuperação foi calculada a Fmed referente a todo o período (Fmedr). parâmetro utilizado no cálculo do índice de recuperação muscular (IRM). Os resultados apontam que a Fmedf apresentou valor menor em relação à Fmedi em ambos os grupos (p < 0,05). Quando comparado com o grupo de sedentários, o grupo de atletas apresentou valores maiores de Fmedi e Fmedf (p < 0,05). O valor médio e desvio-padrão do IRM para o grupo de atletas foram de 62,1% ± 28,7 e, para o grupo de sedentários, de 55,2% ± 27,8 (p > 0,05). Dessa forma, os resultados apresentados neste estudo permitem inferir a viabilidade na aplicação de parâmetros no domínio da freqüência do sinal EMG para a determinação e diferenciação do comportamento da fadiga muscular localizada.
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Magnus CR, Farthing JP. Greater bilateral deficit in leg press than in handgrip exercise might be linked to differences in postural stability requirements. Appl Physiol Nutr Metab 2008; 33:1132-9. [DOI: 10.1139/h08-101] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bilateral deficit is defined as the difference in the summed force between contracting muscles alone and contracting contralateral homologous muscles in combination. The purpose of the study was to investigate how postural stability influences bilateral deficit by comparing an exercise requiring more postural stability (the leg press) with an exercise requiring less postural stability (the handgrip). Eight participants volunteered for the study (3 males, 5 females). Maximal strength was determined by a 1-repetition maximum for the leg press (weight machine) and handgrip (dynamometer) exercises. Electromyography was used to measure activation of the effectors (flexor carpi ulnaris for the handgrip and vastus lateralis for the leg press) and the core muscles (rectus abdominis and external obliques). Bilateral deficit was greater in the leg press (–12.08 ± 10.22%) than the handgrip (–0.677 ± 5.00%; p < 0.05). Muscle activation of the effectors and core muscles was not significantly different between unilateral and bilateral conditions for either exercise. However, core muscle activation was significantly greater during the leg press (48.30 ± 19.60 µV) than during the handgrip (16.50 ± 8.10 µV; p < 0.05) exercise. These results support the hypothesis that an exercise requiring more postural stability (e.g., the leg press) will have a larger deficit and greater activation of core muscles than an exercise requiring less postural stability (e.g., the handgrip). Since the bilateral deficit was only apparent for the leg press exercise, we conclude that postural stability requirements might influence the magnitude of bilateral deficit.
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Affiliation(s)
- Charlene R.A. Magnus
- College of Kinesiology, University of Saskatchewan, 87 Campus Drive, Saskatoon, SK S7N 5B2, Canada
| | - Jonathan P. Farthing
- College of Kinesiology, University of Saskatchewan, 87 Campus Drive, Saskatoon, SK S7N 5B2, Canada
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Esposito F, Limonta E, Cè E, Gobbo M, Veicsteinas A, Orizio C. Electrical and mechanical response of finger flexor muscles during voluntary isometric contractions in elite rock-climbers. Eur J Appl Physiol 2008; 105:81-92. [PMID: 18830618 DOI: 10.1007/s00421-008-0877-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2008] [Indexed: 11/26/2022]
Abstract
To determine the differences between rock-climbers and controls in finger flexor (FF) motor units (MUs) features and activation strategy, eleven climbers and ten controls volunteered for the study. After maximal voluntary contraction (MVC) assessment, five levels of isometric contractions at 20, 40, 60, 80 and 100% MVC were performed. During contractions, electromyogram (EMG) and mechanomyogram (MMG) were recorded, from which the root mean square (RMS) and mean frequency (MF) were calculated. Climbers showed significantly higher MVC. EMG RMS was statistically higher in climbers than in controls from 60 to 100% MVC. In climbers MMG RMS increased up to 80% MVC, whereas in controls it increased only up to 60% MVC. MMG MF was higher in climbers than in controls from 60 to 100% MVC (P < 0.05). EMG-MMG combined analysis revealed significant differences in MU activation strategy between the two groups. The results are compatible with a shift of climbers' muscles toward faster MUs.
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Affiliation(s)
- Fabio Esposito
- Institute of Physical Exercise, Health and Sport, University of Milan, Via Colombo 71, 20133, Milan, Italy.
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Ebersole KT, Malek DM. Fatigue and the electromechanical efficiency of the vastus medialis and vastus lateralis muscles. J Athl Train 2008; 43:152-6. [PMID: 18345339 DOI: 10.4085/1062-6050-43.2.152] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT The relationship between the amplitudes of the mechanomyographic (MMG) and electromyographic (EMG) signals has been used to examine the "electromechanical efficiency" (EME) of normal and diseased muscle. The EME may help us to better understand the neuromuscular relationship between the vastus medialis and vastus lateralis muscles. OBJECTIVE To examine the EME of the vastus medialis and vastus lateralis muscles during a fatiguing task. DESIGN Repeated-measures design. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS Ten healthy males (age = 23.2 +/- 1.2 years) with no history of knee injury. INTERVENTION(S) Seventy-five consecutive, maximal concentric isokinetic leg extensions at a velocity of 180 degrees /s. MAIN OUTCOMES MEASURE(S) Bipolar surface EMG electrodes were placed over the vastus medialis and vastus lateralis muscles, with an MMG contact sensor placed adjacent to the superior EMG electrode on each muscle. The MMG and EMG amplitude values (root mean squares) were calculated for each of the 75 repetitions and normalized to the highest value from the 75 repetitions. The EME was expressed as the ratio of the log-transformed normalized MMG amplitude to the normalized EMG amplitude. For each muscle, the linear relationship for the normalized-group mean EME was determined across the 75 repetitions. RESULTS Linear regression indicated decreases in torque (R(2) = .96), vastus medialis EME (R(2) = .73), and vastus lateralis EME (R(2) = .73). The slopes for the vastus medialis and vastus lateralis EME were not different (P > .10). CONCLUSIONS The similarities in the fatigue-induced decreases in EME for the vastus medialis and vastus lateralis muscles suggested that symmetry was present between the muscles in the electric and mechanical responses to repeated, maximal muscle actions. The EME measurements may provide a unique insight into the influence of fatigue on the contractile properties of skeletal muscle, including alterations that occur to the intrinsic electric and mechanical components. The EME may be useful in assessing and quantifying clinically relevant asymmetries in vastus medialis and vastus lateralis muscle function in those with knee injuries.
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Affiliation(s)
- Kyle T Ebersole
- University of Illinois at Urbana-Champaign, Kinesiology and Community Health, Urbana, IL 61801, USA.
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Al-Zahrani E, Gunasekaran C, Callaghan M, Gaydecki P, Benitez D, Oldham J. Within-day and between-days reliability of quadriceps isometric muscle fatigue using mechanomyography on healthy subjects. J Electromyogr Kinesiol 2008; 19:695-703. [PMID: 18294866 DOI: 10.1016/j.jelekin.2007.12.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 12/29/2007] [Accepted: 12/29/2007] [Indexed: 10/22/2022] Open
Abstract
This study aimed to examine within-day and between-days intratester reliability of mechanomyography (MMG) in assessing muscle fatigue. An accelerometer was used to detect the MMG signal from rectus femoris. Thirty one healthy subjects (15 males) with no prior knee problems initially performed three maximum voluntary contractions (MVCs) using an ISOCOM dynamometer. After 10 min rest, subjects performed a fatiguing protocol in which they performed three isometric knee extensions at 75% MVC for 40 s. The fatiguing protocol was repeated on two other days, two to four days apart for between-days reliability. MMG activity was determined by overall root mean squared amplitude (RMS), mean power frequency (MPF) and median frequency (MF) during a 40s contraction. RMS, MPF and MF linear regression slopes were also analysed. Intraclass Correlation Coefficients (ICC); ICC1,1 and ICC1,2 were used to assess within-day reliability and between-days reliability respectively. Standard error of measurement (SEM) and smallest detectable difference (SDD) described the within-subjects variability. MMG fatigue measures using linear regression slopes showed low reliability and large between-days error (ICC1,2=0.43-0.46; SDD=306.0-324.8% for MPF and MF slopes respectively). Overall MPF and MF, on the other hand, were reliable with high ICCs and lower SDDs compared to linear slopes (ICC1,2=0.79-0.83; SDD=21.9-22.8% for MPF and MF respectively). ICC1,2 for overall MMG RMS and linear RMS slopes were 0.81 and 0.66 respectively; however, the SDDs were high (56.4% and 268.8% respectively). The poor between-days reliability found in this study suggests caution in using MMG RMS, MPF and MF and their corresponding slopes in assessing muscle fatigue.
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Affiliation(s)
- Edan Al-Zahrani
- Centre for Rehabilitation Science, The University of Manchester, Oxford Road, Manchester, M13 9WL, UK.
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