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Marina M, Torrado P, Duchateau J, Baudry S. Neural Adjustments during Repeated Braking and Throttle Actions on a Motorcycle Setup. Int J Sports Med 2024; 45:125-133. [PMID: 38096909 DOI: 10.1055/a-2197-0967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
The aim of the study was to assess neuromuscular changes during an intermittent fatiguing task designed to replicate fundamental actions and ergonomics of road race motorcycling. Twenty-eight participants repeated a sequence of submaximal brake-pulling and gas throttle actions, interspaced by one maximal brake-pulling, until failure. During the submaximal brake-pulling actions performed at 30% MVC, force fluctuations, surface EMG, maximal M-wave (Mmax) and H-reflex were measured in the flexor digitorum superficialis. At the end of the task, the MVC force and associated EMG activity decreased (P<0.001) by 46% and 26%, respectively. During the task, force fluctuation and EMG activity increased gradually (106% and 61%, respectively) with respect to the pre-fatigue state (P≤0.029). The Mmax first phase did not change (P≥0.524), whereas the H-reflex amplitude, normalized to Mmax, increased (149%; P≤0.039). Noteworthy, the relative increase in H-reflex amplitude was correlated with the increase in EMG activity during the task (r=0.63; P<0.001). During the 10-min recovery, MVC force and EMG activity remained depressed (P≤0.05) whereas H-reflex amplitude and force fluctuation returned to pre-fatigue values. In conclusion, contrarily to other studies, our results bring forward that when mimicking motorcycling brake-pulling and gas throttle actions, supraspinal neural mechanisms primarily limit the duration of the performance.
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Affiliation(s)
- Michel Marina
- Research Group in Physical Activity and Health (GRAFAiS), Institut Nacional d'Educació Física de Catalunya (INEFC) - Universitat de Barcelona (UB), Barcelona, Spain
| | - Priscila Torrado
- Research Group in Physical Activity and Health (GRAFAiS), Institut Nacional d'Educació Física de Catalunya (INEFC) - Universitat de Barcelona (UB), Barcelona, Spain
| | - Jacques Duchateau
- Laboratory of Applied Biology, Research Unit in Applied Neurophysiology (LABNeuro), ULB Université Libre de Bruxelles, Bruxelles, Belgium
| | - Stephane Baudry
- Laboratory of Applied Biology, Research Unit in Applied Neurophysiology (LABNeuro), ULB Université Libre de Bruxelles, Bruxelles, Belgium
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Shiang A, Wang JS, Cho DH, Kushner B, Panahi AK, Awad MM. Patient Factors Affect Ergonomic Strain of Endoscopists During Colonoscopy. Dig Dis Sci 2023; 68:736-743. [PMID: 36352078 DOI: 10.1007/s10620-022-07721-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 10/04/2022] [Indexed: 11/11/2022]
Abstract
INTRODUCTION Endoscopic procedures place a great deal of muscular strain on providers, especially over the span of their careers. In this study we quantitatively analyzed the effects of patient factors such as age, body mass index, and sex on the ergonomics of endoscopists performing colonoscopies. METHODS Surface electromyography (sEMG) was used to measure ergonomic strain of physicians while performing colonoscopies in several key muscle groups. The percent of the maximum voluntary contraction (%MVC) was used as a measure of muscular strain. Data was then analyzed based on the patient characteristics above. RESULTS Endoscopists performing colonoscopies on female patients (n = 47) experienced significantly higher ergonomic strain in their right trapezius and right posterior forearm muscle groups when compared to colonoscopies performed on males (n = 35) (%MVC R-trapezius: Male: 8.2; Female: 8.9; p = 0.048); (%MVC R-posterior forearm: Male: 10.4; Female: 11.6; p = 0.0006). Operators experienced greater strain in the same muscle groups when performing colonoscopies on patients with BMI ≤ 25 (n = 25) when compared to patients with BMI > 25 (n = 57) (%MVC R-trapezius: BMI < 25: 9.7; BMI ≥ 25: 8.2; p = 0.0002); (%MVC R-posterior forearm: BMI < 25: 11.9; BMI ≥ 25: 10.8; p = 0.0001). CONCLUSION Physicians experienced greater ergonomic strain when performing colonoscopies on female patients and on patients with a BMI < 25. We believe that these factors potentially impact the tortuosity of the colon and therefore influence the difficulty of navigating the endoscope. These results may aid physicians in gauging the anticipated difficulty of colonoscopies based on patient factors. Increased awareness of their posturing and ergonomics during challenging cases will alleviate musculoskeletal injuries in the long run.
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Affiliation(s)
- Alexander Shiang
- Washington University in St. Louis, 660 S. Euclid Ave, Campus Box 8077, St. Louis, MO, 63110, USA.
| | - Jean S Wang
- Washington University in St. Louis, 660 S. Euclid Ave, Campus Box 8077, St. Louis, MO, 63110, USA
| | | | - Bradley Kushner
- Washington University in St. Louis, 660 S. Euclid Ave, Campus Box 8077, St. Louis, MO, 63110, USA
| | - Ali K Panahi
- Nova Southeastern University, Fort Lauderdale, USA
| | - Michael M Awad
- Washington University in St. Louis, 660 S. Euclid Ave, Campus Box 8077, St. Louis, MO, 63110, USA
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Gabriel DA. Teaching Essential EMG Theory to Kinesiologists and Physical Therapists Using Analogies Visual Descriptions, and Qualitative Analysis of Biophysical Concepts. SENSORS (BASEL, SWITZERLAND) 2022; 22:6555. [PMID: 36081014 PMCID: PMC9460425 DOI: 10.3390/s22176555] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/24/2022] [Accepted: 08/28/2022] [Indexed: 06/15/2023]
Abstract
Electromyography (EMG) is a multidisciplinary field that brings together allied health (kinesiology and physical therapy) and the engineering sciences (biomedical and electrical). Since the physical sciences are used in the measurement of a biological process, the presentation of the theoretical foundations of EMG is most conveniently conducted using math and physics. However, given the multidisciplinary nature of EMG, a course will most likely include students from diverse backgrounds, with varying levels of math and physics. This is a pedagogical paper that outlines an approach for teaching foundational concepts in EMG to kinesiologists and physical therapists that uses a combination of analogies, visual descriptions, and qualitative analysis of biophysical concepts to develop an intuitive understanding for those who are new to surface EMG. The approach focuses on muscle fiber action potentials (MFAPs), motor unit action potentials (MUAPs), and compound muscle action potentials (CMAPs) because changes in these waveforms are much easier to identify and describe in comparison to the surface EMG interference pattern (IP).
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Affiliation(s)
- David A Gabriel
- Electromyographic Kinesiology Laboratory, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1, Canada
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Amezquita-Garcia J, Bravo-Zanoguera M, Gonzalez-Navarro FF, Lopez-Avitia R, Reyna MA. Applying Machine Learning to Finger Movements Using Electromyography and Visualization in Opensim. SENSORS 2022; 22:s22103737. [PMID: 35632146 PMCID: PMC9144461 DOI: 10.3390/s22103737] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/29/2022] [Accepted: 05/01/2022] [Indexed: 01/25/2023]
Abstract
Electromyographic signals have been used with low-degree-of-freedom prostheses, and recently with multifunctional prostheses. Currently, they are also being used as inputs in the human–computer interface that controls interaction through hand gestures. Although there is a gap between academic publications on the control of an upper-limb prosthesis developed in laboratories and its service in the natural environment, there are attempts to achieve easier control using multiple muscle signals. This work contributes to this, using a database and biomechanical simulation software, both open access, to seek simplicity in the classifiers, anticipating their implementation in microcontrollers and their execution in real time. Fifteen predefined finger movements of the hand were identified using classic classifiers such as Bayes, linear and quadratic discriminant analysis. The idealized movements of the database were modeled with Opensim for visualization. Combinations of two preprocessing methods—the forward sequential selection method and the feature normalization method—were evaluated to increase the efficiency of these classifiers. The statistical methods of cross-validation, analysis of variance (ANOVA) and Duncan were used to validate the results. Furthermore, the classifier with the best recognition result was redesigned into a new feature space using the sparse matrix algorithm to improve it, and to determine which features can be eliminated without degrading the classification. The classifiers yielded promising results—the quadratic discriminant being the best, achieving an average recognition rate for each individual considered of 96.16%, and with 78.36% for the total sample group of the eight subjects, in an independent test dataset. The study ends with the visual analysis under Opensim of the classified movements, in which the usefulness of this simulation tool is appreciated by revealing the muscular participation, which can be useful during the design of a multifunctional prosthesis.
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Affiliation(s)
- Jose Amezquita-Garcia
- Facultad de Ingeniería, Universidad Autónoma de Baja California, Mexicali 21280, Mexico; (J.A.-G.); (R.L.-A.)
| | - Miguel Bravo-Zanoguera
- Facultad de Ingeniería, Universidad Autónoma de Baja California, Mexicali 21280, Mexico; (J.A.-G.); (R.L.-A.)
- Ingeniería en Mecatrónica, Universidad Politécnica de Baja California, Mexicali 21376, Mexico
- Correspondence:
| | - Felix F. Gonzalez-Navarro
- Instituto de Ingeniería, Universidad Autónoma de Baja California, Mexicali 21280, Mexico; (F.F.G.-N.); (M.A.R.)
| | - Roberto Lopez-Avitia
- Facultad de Ingeniería, Universidad Autónoma de Baja California, Mexicali 21280, Mexico; (J.A.-G.); (R.L.-A.)
| | - M. A. Reyna
- Instituto de Ingeniería, Universidad Autónoma de Baja California, Mexicali 21280, Mexico; (F.F.G.-N.); (M.A.R.)
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Green LA, McGuire J, Gabriel DA. Effects of the Proprioceptive Neuromuscular Facilitation Contraction Sequence on Motor Skill Learning-Related Increases in the Maximal Rate of Wrist Flexion Torque Development. Front Hum Neurosci 2021; 15:764660. [PMID: 34803640 PMCID: PMC8595484 DOI: 10.3389/fnhum.2021.764660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/13/2021] [Indexed: 11/30/2022] Open
Abstract
Background: The proprioceptive neuromuscular facilitation (PNF) reciprocal contraction pattern has the potential to increase the maximum rate of torque development. However, it is a more complex resistive exercise task and may interfere with improvements in the maximum rate of torque development due to motor skill learning, as observed for unidirectional contractions. The purpose of this study was to examine the cost-benefit of using the PNF exercise technique to increase the maximum rate of torque development. Methods: Twenty-six participants completed isometric maximal extension-to-flexion (experimental PNF group) or flexion-only (control group) contractions at the wrist. Ten of the assigned contractions were performed on each of three sessions separated by 48-h for skill acquisition. Retention was assessed with 5 contractions performed 2-weeks after acquisition. Torque and surface electromyographic (sEMG) activity were analyzed for evidence of facilitated contractions between groups, as well as alterations in muscle coordination assessed across test sessions. The criterion measures were: mean maximal isometric wrist flexion toque; the maximal rate of torque development (dτ/dtmax); root-mean-square error (RMSE) variability of the rate of torque versus torque phase-plane; the rate of wrist flexion muscle activation (Q30); a coactivation ratio for wrist flexor and extensor sEMG activity; and wrist flexor electromechanical delay (EMD). Results: There were no significant differences between groups with respect to maximal wrist flexion torque, dτ/dtmax or RMSE variability of torque trajectories. Both groups exhibited a progressive increase in maximal strength (+23.35% p < 0.01, η2 = 0.655) and in dτ/dtmax (+19.84% p = 0.08, η2 = 0.150) from the start of acquisition to retention. RMSE was lowest after a 2-week rest interval (−18.2% p = 0.04, η2 = 0.198). There were no significant differences between groups in the rate of muscle activation or the coactivation ratio. There was a reduction in coactivation that was retained after a 2-week rest interval (−32.60%, p = 0.02, η2 = 0.266). Alternatively, EMD was significantly greater in the experimental group (Δ 77.43%, p < 0.01, η2 = 0.809) across all sessions. However, both groups had a similar pattern of improvement to the third consecutive day of testing (−16.82%, p = 0.049, η2 = 0.189), but returned close to baseline value after the 2-week rest interval. Discussion: The wrist extension-to-flexion contraction pattern did not result in a greater maximal rate of torque development than simple contractions of the wrist flexors. There was no difference between groups with respect to motor skill learning. The main adaptation in neuromotor control was a decrease in coactivation, not the maximal rate of muscle activation.
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Affiliation(s)
- Lara A Green
- Electromyographic Kinesiology Laboratory, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada.,Exercise Neuroscience Laboratory, Department of Kinesiology, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Jessica McGuire
- Electromyographic Kinesiology Laboratory, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada
| | - David A Gabriel
- Electromyographic Kinesiology Laboratory, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada
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Chimera NJ, Holmes MWR, Gabriel DA. Anthropometrics and electromyography as predictors for maximal voluntary isometric wrist torque: Considerations for ergonomists. APPLIED ERGONOMICS 2021; 97:103496. [PMID: 34171571 DOI: 10.1016/j.apergo.2021.103496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 05/26/2021] [Accepted: 06/04/2021] [Indexed: 06/13/2023]
Abstract
The purpose of this study was to evaluate anthropometry and forearm muscle activity as predictors of maximal isometric wrist torque. Thirteen anthropometric measures, forearm electromyography from flexor carpi radialis (FCR) and extensor carpi radialis (ECR), and maximal isometric wrist flexion/extension torque were obtained from 25 male participants. Pearson correlation coefficients assessed relationships between peak isometric torque and: (1) anthropometrics, (2) FCR and ECR activation, (3) FCR/ECR antagonist/agonist coactivation ratios. Based on significant correlations, linear regression equations were developed (SPSS v.25; p < 0.05). Hand thickness, forearm circumference and ECR activation or hand thickness, elbow circumference, FCR activation and body weight were most highly correlated with extension or flexion torque, respectively. Hand thickness, forearm circumference, and ECR activation (R2 = 54.5%; p = 0.001) and hand thickness, elbow circumference, FCR activation (R2 = 68.3%; p < 0.001) explained similar variance in torque regressions as did the addition of body weight to extension (R2 = 58.0%; p = 0.001) and flexion (R2 = 69.9%; p < 0.001) torque regression equations, respectively. Circumference measurements, a pseudo for muscle size, and activation amplitude influenced wrist force output more than limb length or coactivation.
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Affiliation(s)
- Nicole J Chimera
- Department of Kinesiology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, Canada.
| | - Michael W R Holmes
- Department of Kinesiology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, Canada
| | - David A Gabriel
- Department of Kinesiology, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, Canada
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Geng Y, Deng H, Samuel OW, Cheung V, Xu L, Li G. Modulation of muscle synergies for multiple forearm movements under variant force and arm position constraints. J Neural Eng 2020; 17:026015. [PMID: 32126534 DOI: 10.1088/1741-2552/ab7c1a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To promote clinical applications of muscle-synergy-based neurorehabilitation techniques, this study aims to clarify any potential modulations of both the muscular compositions and temporal activations of forearm muscle synergies for multiple movements under variant force levels and arm positions. APPROACH Two groups of healthy subjects participated in this study. Electromyography (EMG) signals were collected when they performed four hand and wrist movements under variant constraints-three different force levels for one group and five arm positions for the other. Muscle synergies were extracted from the EMGs, and their robustness across variant force levels and arm positions was separately assessed by evaluating their across-condition structure similarity, cross-validation, and cluster analysis. The synergies' activation coefficients across the variant constraints were also compared, and the coefficients were used to discriminate the different force levels and the arm positions, respectively. MAIN RESULTS Overall, the muscle synergies were relatively fixed across variant constraints, but they were more robust to variant forces than to changing arm positions. The activations of muscle synergies depended largely on the level of contraction force and could discriminate the force levels very well, but the coefficients corresponding to different arm positions discriminated the positions with lower accuracy. Similar results were found for all types of forearm movement analyzed. SIGNIFICANCE With our experiment and subject-specific analysis, only slight modulation of the muscular compositions of forearm muscle synergies was found under variant force and arm position constraints. Our results may shed valuable insights to future design of both muscle-synergy-based assistive robots and motor-function assessments.
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Affiliation(s)
- Yanjuan Geng
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen 518055, People's Republic of China. Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen 518055, People's Republic of China
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Mallette MM, Cheung SS, Kumar RI, Hodges GJ, Holmes MWR, Gabriel DA. The effects of local forearm heating and cooling on motor unit properties during submaximal contractions. Exp Physiol 2020; 106:200-211. [DOI: 10.1113/ep088256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/07/2020] [Indexed: 11/08/2022]
Affiliation(s)
- Matthew M. Mallette
- Department of Kinesiology and Physical Education Wilfrid Laurier University Waterloo Ontario Canada
- Department of Kinesiology Brock University St Catharines Ontario Canada
| | - Stephen S. Cheung
- Department of Kinesiology Brock University St Catharines Ontario Canada
| | - Robert I. Kumar
- Department of Kinesiology Brock University St Catharines Ontario Canada
| | - Gary J. Hodges
- Department of Kinesiology Brock University St Catharines Ontario Canada
| | | | - David A. Gabriel
- Department of Kinesiology Brock University St Catharines Ontario Canada
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Mallette MM, Green LA, Hodges GJ, Fernley RE, Gabriel DA, Holmes MWR, Cheung SS. The effects of local muscle temperature on force variability. Eur J Appl Physiol 2019; 119:1225-1233. [DOI: 10.1007/s00421-019-04112-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 02/26/2019] [Indexed: 10/27/2022]
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Green LA, Gabriel DA. The cross education of strength and skill following unilateral strength training in the upper and lower limbs. J Neurophysiol 2018. [PMID: 29668382 DOI: 10.1152/jn.00116.2018.-cross] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023] Open
Abstract
UNLABELLED Cross education is the strength gain or skill improvement transferred to the contralateral limb following unilateral training or practice. The present study examined the transfer of both strength and skill following a strength training program. Forty participants (20M, 20F) completed a 6-wk unilateral training program of dominant wrist flexion or dorsiflexion. Strength, force variability, and muscle activity were assessed pretraining, posttraining, and following 6 wk of detraining (retention). Analyses of covariance compared the experimental limb (trained or untrained) to the control (dominant or nondominant). There were no sex differences in the training response. Cross education of strength at posttraining was 6% ( P < 0.01) in the untrained arm and 13% ( P < 0.01) in the untrained leg. Contralateral strength continued to increase following detraining to 15% in the arm ( P < 0.01) and 14% in the leg ( P < 0.01). There was no difference in strength gains between upper and lower limbs ( P > 0.05). Cross education of skill (force variability) demonstrated greater improvements in the untrained limbs compared with the control limbs during contractions performed without concurrent feedback. Significant increases in V-wave amplitude ( P = 0.02) and central activation ( P < 0.01) were highly correlated with contralateral strength gains. There was no change in agonist amplitude or motor unit firing rates in the untrained limbs ( P > 0.05). The neuromuscular mechanisms mirrored the force increases at posttraining and retention supporting central drive adaptations of cross education. The continued strength increases at retention identified the presence of motor learning in cross education, as confirmed by force variability. NEW & NOTEWORTHY We examined cross education of strength and skill following 6 wk of unilateral training and 6 wk of detraining. A novel finding was the continued increase in contralateral strength following both training and detraining. Neuromuscular adaptations were highly correlated with strength gains in the trained and contralateral limbs. Motor learning was evident in the trained and contralateral limbs during contractions performed without concurrent feedback.
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Affiliation(s)
- Lara A Green
- Department of Kinesiology, Brock University , St. Catharines, Ontario , Canada
| | - David A Gabriel
- Department of Kinesiology, Brock University , St. Catharines, Ontario , Canada
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Green LA, Gabriel DA. The cross education of strength and skill following unilateral strength training in the upper and lower limbs. J Neurophysiol 2018; 120:468-479. [PMID: 29668382 DOI: 10.1152/jn.00116.2018] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cross education is the strength gain or skill improvement transferred to the contralateral limb following unilateral training or practice. The present study examined the transfer of both strength and skill following a strength training program. Forty participants (20M, 20F) completed a 6-wk unilateral training program of dominant wrist flexion or dorsiflexion. Strength, force variability, and muscle activity were assessed pretraining, posttraining, and following 6 wk of detraining (retention). Analyses of covariance compared the experimental limb (trained or untrained) to the control (dominant or nondominant). There were no sex differences in the training response. Cross education of strength at posttraining was 6% ( P < 0.01) in the untrained arm and 13% ( P < 0.01) in the untrained leg. Contralateral strength continued to increase following detraining to 15% in the arm ( P < 0.01) and 14% in the leg ( P < 0.01). There was no difference in strength gains between upper and lower limbs ( P > 0.05). Cross education of skill (force variability) demonstrated greater improvements in the untrained limbs compared with the control limbs during contractions performed without concurrent feedback. Significant increases in V-wave amplitude ( P = 0.02) and central activation ( P < 0.01) were highly correlated with contralateral strength gains. There was no change in agonist amplitude or motor unit firing rates in the untrained limbs ( P > 0.05). The neuromuscular mechanisms mirrored the force increases at posttraining and retention supporting central drive adaptations of cross education. The continued strength increases at retention identified the presence of motor learning in cross education, as confirmed by force variability. NEW & NOTEWORTHY We examined cross education of strength and skill following 6 wk of unilateral training and 6 wk of detraining. A novel finding was the continued increase in contralateral strength following both training and detraining. Neuromuscular adaptations were highly correlated with strength gains in the trained and contralateral limbs. Motor learning was evident in the trained and contralateral limbs during contractions performed without concurrent feedback.
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Affiliation(s)
- Lara A Green
- Department of Kinesiology, Brock University , St. Catharines, Ontario , Canada
| | - David A Gabriel
- Department of Kinesiology, Brock University , St. Catharines, Ontario , Canada
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Coletta NA, Mallette MM, Gabriel DA, Tyler CJ, Cheung SS. Core and skin temperature influences on the surface electromyographic responses to an isometric force and position task. PLoS One 2018; 13:e0195219. [PMID: 29596491 PMCID: PMC5875857 DOI: 10.1371/journal.pone.0195219] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 03/19/2018] [Indexed: 11/25/2022] Open
Abstract
The large body of work demonstrating hyperthermic impairment of neuromuscular function has utilized maximal isometric contractions, but extrapolating these findings to whole-body exercise and submaximal, dynamic contractions may be problematic. We isolated and compared core and skin temperature influences on an isometric force task versus a position task requiring dynamic maintenance of joint angle. Surface electromyography (sEMG) was measured on the flexor carpi radialis at 60% of baseline maximal voluntary contraction while either pushing against a rigid restraint (force task) or while maintaining a constant wrist angle and supporting an equivalent inertial load (position task). Twenty participants performed each task at 0.5°C rectal temperature (Tre) intervals while being passively heated from 37.1±0.3°C to ≥1.5°C Tre and then cooled to 37.8±0.3°C, permitting separate analyses of core versus skin temperature influences. During a 3-s contraction, trend analysis revealed a quadratic trend that peaked during hyperthermia for root-mean-square (RMS) amplitude during the force task. In contrast, RMS amplitude during the position task remained stable with passive heating, then rapidly increased with the initial decrease in skin temperature at the onset of passive cooling (p = 0.010). Combined hot core and hot skin elicited shifts toward higher frequencies in the sEMG signal during the force task (p = 0.003), whereas inconsistent changes in the frequency spectra occurred for the position task. Based on the patterns of RMS amplitude in response to thermal stress, we conclude that core temperature was the primary thermal afferent influencing neuromuscular response during a submaximal force task, with minimal input from skin temperature. However, skin temperature was the primary thermal afferent during a position task with minimal core temperature influence. Therefore, temperature has a task-dependent impact on neuromuscular responses.
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Affiliation(s)
- Nico A. Coletta
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Matthew M. Mallette
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - David A. Gabriel
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | | | - Stephen S. Cheung
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
- * E-mail:
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The effects of local forearm muscle cooling on motor unit properties. Eur J Appl Physiol 2017; 118:401-410. [DOI: 10.1007/s00421-017-3782-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 12/03/2017] [Indexed: 10/18/2022]
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Inglis JG, McIntosh K, Gabriel DA. Neural, biomechanical, and physiological factors involved in sex-related differences in the maximal rate of isometric torque development. Eur J Appl Physiol 2016; 117:17-26. [PMID: 27815705 PMCID: PMC5306324 DOI: 10.1007/s00421-016-3495-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 10/21/2016] [Indexed: 11/17/2022]
Abstract
Objective Recent research has reported that lower maximal rate of torque development (dτ/dtmax) exhibited by females, relative to males, during knee extension can be accounted for by normalization to a maximal voluntary contraction (MVC); however, this was not seen in the upper limb. Purpose The aim of the current work was to examine the contribution of maximum strength (τmax), twitch contraction time (CT), muscle fiber condition velocity (MFCV), and rate of muscle activation (Q30) to sex-differences in the dτ/dtmax during maximal isometric dorsiflexion. Methods Thirty-eight participants (20 males; 18 females) performed both maximal voluntary and evoked isometric contractions of the tibialis anterior across 3 days. Ten maximal compound muscle action potentials were elicited and subsequently followed by three, 5-s contractions. From the recordings, MFCV, dτ/dtmax, τmax, CT, electromechanical delay (EMD), root-mean squared (RMS) amplitude, peak-to-peak voltage (Vpp), and Q30 were calculated. Results An ANCOVA showed that τmax accounted for all the sex-differences in dτ/dtmax (p = 0.96). There were no significant differences between groups with respect to MFCV, RMS amplitude, Vpp amplitude, or CT. However, there was a significant sex-difference in dτ/dtmax, τmax, and Q30. Females had longer evoked EMD times compared with males (15.69 ± 10.57 ms versus 9.95 ± 3.46 ms; p = 0.01), but the voluntary EMD times were not different. Conclusion The current research supports the work by Hannah et al. Exp Physiol 97:618–629, (2012) that normalization to MVC in the quadriceps is able to account for all sex-differences in rate of toque development in the lower limb.
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Affiliation(s)
- J Greig Inglis
- Electromyographic Kinesiology Laboratory, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada.
| | - Kyle McIntosh
- Electromyographic Kinesiology Laboratory, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
| | - David A Gabriel
- Electromyographic Kinesiology Laboratory, Faculty of Applied Health Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S 3A1, Canada
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Sanchez B, Pacheck A, Rutkove SB. Guidelines to electrode positioning for human and animal electrical impedance myography research. Sci Rep 2016; 6:32615. [PMID: 27585740 PMCID: PMC5009322 DOI: 10.1038/srep32615] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 08/10/2016] [Indexed: 12/14/2022] Open
Abstract
The positioning of electrodes in electrical impedance myography (EIM) is critical for accurately assessing disease progression and effectiveness of treatment. In human and animal trials for neuromuscular disorders, inconsistent electrode positioning adds errors to the muscle impedance. Despite its importance, how the reproducibility of resistance and reactance, the two parameters that define EIM, are affected by changes in electrode positioning remains unknown. In this paper, we present a novel approach founded on biophysical principles to study the reproducibility of resistance and reactance to electrode misplacements. The analytical framework presented allows the user to quantify a priori the effect on the muscle resistance and reactance using only one parameter: the uncertainty placing the electrodes. We also provide quantitative data on the precision needed to position the electrodes and the minimum muscle length needed to achieve a pre-specified EIM reproducibility. The results reported here are confirmed with finite element model simulations and measurements on five healthy subjects. Ultimately, our data can serve as normative values to enhance the reliability of EIM as a biomarker and facilitate comparability of future human and animal studies.
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Affiliation(s)
- Benjamin Sanchez
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, USA
| | - Adam Pacheck
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, USA
| | - Seward B Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215-5491, USA
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Local Band Spectral Entropy Based on Wavelet Packet Applied to Surface EMG Signals Analysis. ENTROPY 2016. [DOI: 10.3390/e18020041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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