scholarly journals Effect of elbow joint angles on electromyographic activity versus force relationships of synergistic muscles of the triceps brachii

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252644
Author(s):  
Hiroshi Akima ◽  
Hisashi Maeda ◽  
Teruhiko Koike ◽  
Koji Ishida
Keyword(s):  
Elbow Joint ◽  
Joint Angle ◽  
Surface Emg ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Joint Angles ◽  
Triceps Brachii ◽  
Neuromuscular Activation ◽  
Force Matching ◽  
Force Relationship

The electromyographic (EMG) activity and force relationship, i.e. EMG-force relationship, is a valuable indicator of the degree of the neuromuscular activation during isometric force production. However, there is minimal information available regarding the EMG-force relationship of individual triceps brachii (TB) muscles at different elbow joint angles. This study aimed to compare the EMG-force relationships of the medial (TB-Med), lateral (TB-Lat), and long heads (TB-Long) of the TB. 7 men and 10 women performed force matching isometric tasks at 20%, 40%, 60%, and 80%maximum voluntary contraction (MVC) at 60°, 90°, and 120° of extension. During the submaximal force matching tasks, the surface EMG signals of the TB-Med, TB-Lat, and TB-Long were recorded and calculated the root mean square (RMS). RMS of each force level were then normalized by RMS at 100%MVC. For the TB-Med, ultrasonography was used to determine the superficial region of the muscle that faced the skin surface to minimize cross-talk. The joint angle was monitored using an electrogoniometer. The elbow extension force, elbow joint angle, and surface EMG signals were simultaneously sampled at 2 kHz and stored on a personal computer. The RMS did not significantly differ between the three muscles, except between the TB-Med and TB-Lat during 20%MVC at 60°. The RMS during force levels of ≥ 60%MVC at 120° was significantly lower than that at 60° or 90° for each muscle. The sum of difference, which represents the difference in RMS from the identical line, did not significantly differ in any of the assessed muscles in the present study. This suggests that a relatively smaller neuromuscular activation could be required when the elbow joint angle was extended. However, neuromuscular activation levels and relative force levels were matched in all three TB synergists when the elbow joint angle was at 90° or a more flexed position.

scholarly journals Estimation of Continuous Joint Angles of Upper Limb Based on sEMG by Using GA-Elman Neural Network

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Junhong Wang ◽  
Qiqi Hao ◽  
Xugang Xi ◽  
Jiuwen Cao ◽  
Anke Xue ◽  
...  
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Elbow Joint ◽  
Joint Angle ◽  
Wavelet Packet ◽  
Upper Limbs ◽  
Joint Angles ◽  
Semg Signal ◽  
Elman Neural Network ◽  
Shoulder Movement

The estimation of continuous and simultaneous multijoint angle based on surface electromyography (sEMG) signal is of considerable significance in rehabilitation practice. However, there are few studies on the continuous joint angle of multiple joints at present. In this paper, the wavelet packet energy entropy (WPEE) of the special subspace was investigated as a feature of the sEMG signal. An Elman neural network optimized by genetic algorithm (GA) was established to estimate the joint angle of shoulder and elbow. First, the accuracy of the method is verified by estimating the angle of the shoulder joint. Then, this method was used to simultaneously and continuously estimate the shoulder and elbow joint angle. Six subjects flexed and extended the upper limbs according to the intended movements of the experiment. The results show that this method can obtain a decent performance with a RMSE of 3.4717 and R2 of 0.8283 in shoulder movement and with a RMSE of 4.1582 and R2 of 0.8114 in continuous synchronous movement of the shoulder and elbow.

Mind-Muscle Connection: Verbal Instructions Alter Electromyographic Activity for Elbow Flexors and Extensors During Co-Contraction Training

2020 ◽  
pp. 003151252094908
Author(s):  
Rafael A. Fujita ◽  
Marina M. Villalba ◽  
Nilson R. S. Silva ◽  
Matheus M. Pacheco ◽  
Matheus M. Gomes
Keyword(s):  
Strength Training ◽  
Elbow Joint ◽  
Biceps Brachii ◽  
Elbow Flexion ◽  
Emg Activity ◽  
Elbow Extension ◽  
Verbal Instruction ◽  
Triceps Brachii ◽  
Verbal Instructions ◽  
Lateral Head

Co-contraction training has demonstrated similar electromyographic (EMG) activity levels compared to conventional strength training. Since verbal instructions can increase EMG activity on target muscles during conventional exercises, the same should occur during co-contraction. In this study we analyzed whether different verbal instructions would alter the EMG activity of target muscles - biceps brachii (BB) and triceps brachii lateral head (TB) - during co-contraction training for the elbow joint. Seventeen males with experience in strength training performed a co-contraction set in two verbal instruction conditions to emphasize either elbow flexion or elbow extension. Surface electrodes were fixed over biceps brachii and triceps brachii lateral head muscles. We measured EMG mean amplitude and analyzed data with 2-way ANOVA. We found a significant interaction between muscle and verbal instruction ( p = 0.002). Post hoc tests indicated that verbal instructions ( p = 0.001) influenced the BB EMG activity (elbow flexion: M = 68.74, SD = 17.96%; elbow extension: M = 53.47, SD = 16.13%); and also showed difference ( p = 0.006) in the EMG activity between BB and TB with verbal instruction emphasizing the elbow extension (BB: M = 53.47, SD = 16.13%; TB: M = 69.18, SD = 21.79%). There was a difference in the EMG ratio of BB/TB ( p = 0.001) when focusing on elbow flexion ( M = 1.09, SD = 0.30) versus elbow extension ( M = 0.81, SD = 0.25). As verbal instruction modified the magnitude of muscle recruitment during co-contractions for elbow joint muscles, there is a clear mind-muscle connection of importance to this method of training. Also, of importance to trainers, verbal instructions seemed to affect individuals differentially.

The effect of toe-tap exercise on abductor hallucis activity and medial longitudinal arch angle in individuals with pes planus

2020 ◽  
Vol 28 (4) ◽  
pp. 415-422
Author(s):  
Min-Hyeok Kang ◽  
Sang-Min Cha ◽  
Jae-Seop Oh
Keyword(s):  
Repeated Measures ◽  
Plantar Flexion ◽  
Surface Emg ◽  
Rehabilitation Program ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Medial Longitudinal Arch ◽  
Abductor Hallucis ◽  
Pes Planus ◽  
Longitudinal Arch

BACKGROUND: Active interventions for pes planus, including short-foot exercises (SF) and toe-spread-out exercises (TSO), aim to continuously support the medial longitudinal arch (MLA) by activating the abductor hallucis (AbdH) muscle. However, compensatory movements, such as ankle supination and/or plantar flexion, often occur during these exercises. OBJECTIVE: To examine the effects of a novel exercise, i.e., the toe-tap (TT) exercise on AbdH activity and MLA angle. METHODS: A total of 16 participants with pes planus participated in this study. Participants performed SF, TSO, and TT exercises. Electromyographic activity of the AbdH and MLA angle during three AbdH contraction exercises were recorded using surface EMG system and digital image analysis program, respectively. The differences in outcome measures among the three exercises were analyzed using one-way repeated-measures analysis of variance. RESULTS: The EMG activity of the AbdH was significantly greater during the TT exercise compared to the SF and TSO exercises. The MLA angle was significantly smaller during the TT exercise compared with the SF and TSO exercises. CONCLUSIONS: These findings suggest that the TT exercise could be effective in activating the AbdH and increasing height of the MLA, as part of a sports rehabilitation program for individuals with pes planus.

The Relationship Between Surface Electromyographic Activity and Torque Production of the Infraspinatus Muscle in Shoulder Rehabilitation Exercises

2020 ◽  
Vol 36 (3) ◽  
pp. 141-147
Author(s):  
Bill Stodart ◽  
Maria Cup ◽  
Curtis Kindel
Keyword(s):  
Inverse Relationship ◽  
External Rotation ◽  
Surface Emg ◽  
Joint Torque ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Maximum Voluntary Isometric Contraction ◽  
Relative Value ◽  
Torque Values ◽  
The Relationship

In current rehabilitation practice, exercise selection is commonly based on the amount of muscle recruitment demonstrated by electromyographic (EMG) analysis. A preponderance of evidence supports the concept that EMG of a muscle and torque output are positively correlated. This study was designed to investigate the relationship between surface EMG activity of the infraspinatus and torque production during exercises involving shoulder external rotation (ER). A total of 30 participants (average age = 24.6 y) performed maximum voluntary isometric contraction of ER at 5 points within the range of motion of 3 shoulder exercise positions with concomitant surface EMG recording. As a maximal internally rotated position was approached, maximum ER torque and minimum or near-minimum EMG recruitment were demonstrated. Conversely, at maximally externally rotated positions, EMG activity was greatest and torque values were lowest. An inverse relationship between joint torque output and EMG activity was established in each of the 3 exercises. The inverse relationship between EMG activity and torque output during Shoulder ER suggests that there may be additional factors warranting consideration during exercise selection. Further research may be needed to determine the relative value of electrical activity versus torque output to optimize the selection of rehabilitative exercises.

scholarly journals Effect of Fatigue Upon Performance and Electromyographic Activity in 6-RM Bench Press

2014 ◽  
Vol 40 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Roland van den Tillaar ◽  
Atle Saeterbakken
Keyword(s):  
Bench Press ◽  
Biceps Brachii ◽  
Erector Spinae ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Triceps Brachii ◽  
Antagonist Muscle ◽  
Prime Movers ◽  
And Performance ◽  
Single Set

Abstract The aim of this study was to examine the effect of fatigue during one set of 6-RM bench pressing upon the muscle patterning and performance. Fourteen resistance-trained males (age 22.5±2.0 years, stature 1.82±0.07 m, body mass 82.0±7.8 kg) conducted a 6-RM bench press protocol. Barbell kinematics and EMG activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were measured in each repetition during the 6-RM bench press. Total lifting time increased and the velocity in the ascending movement decreased (p≤0.001). However, the kinematics in the descending phase deferred: the time decreased and velocity increased during the 6-RM (p≤0.001). Generally, muscles increased their EMG amplitude during the six repetitions in the ascending movement, while only three of the seven measured muscles showed an increase over the six repetitions in the descending part in 6-RM bench pressing. It was concluded that the bench pressing performance decreased (lower barbell velocities and longer lifting times) with increasing fatigue in the 6-RM execution. Furthermore EMG increased in the prime movers and the trunk stabilizers (abdominal and spine), while the antagonist muscle (biceps) activity was not affected by fatigue during the lifting phase in a single set of 6-RM bench pressing

EMG-Based Interface for Position Tracking and Control in VR Environments and Teleoperation

1997 ◽  
Vol 6 (3) ◽  
pp. 282-291 ◽  
Author(s):  
Srikanth Suryanarayanan ◽  
Narender P. Reddy
Keyword(s):  
Elbow Joint ◽  
Joint Angle ◽  
Intelligent System ◽  
Normal Subjects ◽  
Surface Emg ◽  
Position Tracking ◽  
Emg Signal ◽  
Human Movements ◽  
Flexion Extension ◽  
And Control

Position tracking and control using bioelectric signals are emerging as promising techniques. Surface electromyographic (EMG) signals are being researched for tracking human movements, direct proportional control of teleoperators, and object manipulation in VR environments. This study investigates the use of surface EMG to track elbow joint angle during flexion-extension of the arm applied to control of a virtual environment or an anthropomorphic telemanipulator. An intelligent system based on neural networks and fuzzy logic has been developed to use the processed surface EMG signal and predict the joint angle. The intelligent system has been tested on normal subjects performing flexion-extension of the arm of various angles and at several speeds. The joint angles predicted by the intelligent system were input to a computer-simulated model of an elbow manipulator. Preliminary results show the average root mean squared (RMS) error between the actual elbow joint angle measured with a goniometer and the joint angle reproduced by the robot model to be less than 20%. The technique of using EMG as an interface for tracking and direct biocontrol has great potential in VR and telemanipulation.

scholarly journals Effect of Five Bench Inclinations on the Electromyographic Activity of the Pectoralis Major, Anterior Deltoid, and Triceps Brachii during the Bench Press Exercise

2020 ◽  
Vol 17 (19) ◽  
pp. 7339
Author(s):  
David Rodríguez-Ridao ◽  
José A. Antequera-Vique ◽  
Isabel Martín-Fuentes ◽  
José M. Muyor
Keyword(s):  
Bench Press ◽  
Pectoralis Major ◽  
Upper Body ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Activity Levels ◽  
Triceps Brachii ◽  
Body Strength ◽  
Upper Body Strength ◽  
Anterior Deltoid

The bench press exercise is one of the most used for training and for evaluating upper-body strength. The aim of the current study was to evaluate the electromyographic (EMG) activity levels of the pectoralis major (PM) in its three portions (upper portion, PMUP, middle portion, PMMP, and lower portion, PMLP), the anterior deltoid (AD), and the triceps brachii (TB) medial head during the bench press exercise at five bench angles (0°, 15°, 30°, 45°, and 60°). Thirty trained adults participated in the study. The EMG activity of the muscles was recorded at the aforementioned inclinations at 60% of one-repetition maximum (1RM). The results showed that the maximal EMG activity for PMUP occurred at a bench inclination of 30°. PMMP and PMLP showed higher EMG activity at a 0° bench inclination. AD had the highest EMG activity at 60°. TB showed similar EMG activities at all bench inclinations. In conclusion, the horizontal bench press produces similar electromyographic activities for the pectoralis major and the anterior deltoid. An inclination of 30° produces greater activation of the upper portion of the pectoralis major. Inclinations greater than 45° produce significantly higher activation of the anterior deltoid and decrease the muscular performance of the pectoralis major.

scholarly journals Comparison of electromyographic activity during the bench press and barbell pulloverexercises

2014 ◽  
Vol 20 (2) ◽  
pp. 200-205 ◽  
Author(s):  
Yuri de Almeida Costa Campos ◽  
Sandro Fernandes da Silva
Keyword(s):  
Resistance Training ◽  
Data Collection ◽  
Latissimus Dorsi ◽  
Bench Press ◽  
Pectoralis Major ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Triceps Brachii ◽  
Dynamic Contractions ◽  
Anterior Deltoid

The aim of the study was to compare the electromyographic (EMG) activity of the following muscles: clavicular portion of pectoralis major, sternal portion of pectoralis major, long portion of triceps brachii, anterior deltoid, posterior deltoid and latissimus dorsi during dynamic contractions between flat horizontal bench press and barbell pulloverexercises. The sample comprised 12 males individuals experienced in resistance training. The volunteers made three visits to the laboratory. The first one consisted of 12 repetitions of the exercises for the electromyographic data collection. The results showed a higher EMG activation of the pectoralis major and anterior deltoid muscles in the flat horizontal bench press in comparison with the barbell pullover. The triceps brachii and latissimus dorsi muscles were more activated in the barbell pullover.

scholarly journals Preference and torque asymmetry for elbow joint

2012 ◽  
Vol 18 (2) ◽  
pp. 319-326 ◽  
Author(s):  
Felipe Pivetta Carpes ◽  
Jeam Marcel Geremia ◽  
Ana Paula Barcellos Karolczak ◽  
Fernando Diefenthaeler ◽  
Marco Aurélio Vaz
Keyword(s):  
Elbow Joint ◽  
Healthy Subjects ◽  
Joint Angle ◽  
Force Production ◽  
Functional Adaptation ◽  
Daily Activities ◽  
Elbow Flexors ◽  
Isokinetic Dynamometer ◽  
Joint Angles ◽  
Angular Velocities

Extensively unilateral recruitment for daily activities may determine performance asymmetries in favor of the preferred side eliciting functional adaptation. Our study evaluated asymmetries in elbow torque output between preferred and non-preferred limbs. Eighteen subjects performed maximal elbow flexor and extensor isometric contractions at five different elbow joint angles (0º, 30º, 60º, 90º, 120º) and five different angular velocities (60, 120, 180, 240, 300º.s-1) on an isokinetic dynamometer. Higher flexor torque in favor of preferred arm was observed at 90º of flexion (p<0.05), which also corresponded to the highest torque produced (p<0.05). The fact that joint angle influenced torque asymmetries, whereas angular velocity did not, suggest that the observed asymmetry is likely related to preferential recruitment of elbow flexors at a 90º joint angle for daily tasks requiring high levels of force production. Muscle functional adaptation to frequent stimuli at this joint angle in healthy subjects may explain these results.

Upper Extremity and Cue Kinematics, and Shoulder Muscle Electromyographic Activity of Novus Players of Different Skill Levels

2017 ◽  
Vol 33 (2) ◽  
pp. 124-129
Author(s):  
Viire Talts ◽  
Jaan Ereline ◽  
Tatjana Kums ◽  
Mati Pääsuke ◽  
Helena Gapeyeva
Keyword(s):  
Upper Extremity ◽  
Movement Analysis ◽  
Trapezius Muscle ◽  
Elbow Flexion ◽  
Surface Emg ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Recruitment Pattern ◽  
Skill Levels ◽  
Analysis System

Our aim with the current study was to compare upper extremity and cue kinematics, and electromyographic (EMG) activation of shoulder muscles during novus (a special form of billiards) shots of different difficulty levels. Ten proficient and 10 less-skilled novus players performed 3 types of novus shots (penalties, cuts, rebounds) 10 times each. During each shot, elbow flexion and cue–forearm angles (using a movement analysis system), and surface EMG activity of the trapezius, posterior, and lateral deltoid muscles of each subject’s dominant side, were measured. Data were compared between more- and less-skilled players, and successful compared with unsuccessful shots. Elbow flexion angle among the more-skilled players was 24.5% larger (P < .001) during unsuccessful cut shots than successful ones. The more-skilled players performed successful penalty and rebound shots with 26.8% and 49.8% lower (P < .01 and P < .001, respectively) EMG activity of the trapezius muscle than unsuccessful ones. Less-skilled players’ shots were characterized by higher EMG activity in the trapezius muscle. The obtained findings suggest that the more-skilled novus players had acquired a different muscle recruitment pattern than less-skilled players.

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