Intra- and Intersession Reliability of Surface Electromyography on Muscles Actuating the Forearm During Maximum Voluntary Contractions

2016 ◽  
Vol 32 (6) ◽  
pp. 558-570 ◽  
Author(s):  
Guillaume Gaudet ◽  
Maxime Raison ◽  
Fabien Dal Maso ◽  
Sofiane Achiche ◽  
Mickael Begon
Keyword(s):  
Surface Electromyography ◽  
Biceps Brachii ◽  
Intraclass Correlation ◽  
Isometric Contractions ◽  
Triceps Brachii ◽  
Pronator Quadratus ◽  
Pronator Teres ◽  
Flexion Extension ◽  
Long Head ◽  
Voluntary Contractions

The aim of this study is to determine the intra- and intersession reliability of nonnormalized surface electromyography (sEMG) on the muscles actuating the forearm during maximum voluntary isometric contractions (MVIC). A subobjective of this study is to determine the intra- and intersession reliability of forearm MVIC force or torque, which is a prerequisite to assess sEMG reliability. Eighteen healthy adults participated at 4 different times: baseline, 1-h post, 6-h post, and 24-h post. They performed 3 MVIC trials of forearm flexion, extension, pronation, and supination. sEMG of the biceps brachii short head, brachialis, brachioradialis, triceps brachii long head, pronator teres, and pronator quadratus were measured. The intraclass correlation coefficient (ICC) on MVIC ranged from 0.36 to 0.99. Reliability was excellent for flexion, extension, and supination MVIC for both intra- and intersession. The ICC on sEMG ranged from 0.58 to 0.99. sEMG reliability was excellent for brachialis, brachioradialis, and pronator quadratus, and good to excellent for triceps brachii, biceps brachii, and pronator teres. This study shows that performing 3 MVICs is sufficient to obtain highly reliable maximal sEMG over 24 h for the main muscles actuating the forearm. These results confirm the potential of sEMG for muscle motor functional monitoring.

Strategies for muscle activation during isometric torque generation at the human elbow

1989 ◽  
Vol 62 (6) ◽  
pp. 1201-1212 ◽  
Author(s):  
T. S. Buchanan ◽  
G. P. Rovai ◽  
W. Z. Rymer
Keyword(s):  
Muscle Activation ◽  
Biceps Brachii ◽  
Human Subjects ◽  
Elbow Flexion ◽  
Emg Activity ◽  
Elbow Extension ◽  
Triceps Brachii ◽  
Pronator Teres ◽  
Flexion Extension ◽  
Torque Generation

1. We studied the patterns of electromyographic (EMG) activity in elbow muscles of 14 normal human subjects. The activity of five muscles that act in flexion-extension and forearm supination-pronation was simultaneously recorded during isometric voluntary torque generation, in which torques generated in a plane orthogonal to the long axis of the forearm were voluntarily coupled with torques generated about the long axis of the forearm (i.e., supination-pronation). 2. When forearm supination torques were superimposed on a background of elbow flexion torque, biceps brachii activity increased substantially, as expected; however, brachioradialis and brachialis EMG levels decreased modestly, a less predictable outcome. The pronator teres was also active during pure flexion and flexion coupled with mild supination (even though no pronation torque was required). This was presumably to offset inappropriate torque contributions of other muscles, such as the biceps brachii. 3. When forearm supination torque was superimposed on elbow extension torque, again the biceps brachii was strongly active. The pronator teres also became mildly active during extension with added pronation torque. These changes occurred despite the fact that both the pronator and biceps muscles induce elbow flexion. 4. In these same elbow extension tasks, triceps brachii activity was also modulated with both pronation or supination loads. It was most active during either supination or pronation loads, again despite the fact that it has no mechanical role in producing forearm supination-pronation torque. 5. Recordings of EMG activity during changes in forearm supination-pronation angle demonstrated that activation of the biceps brachii followed classic length-tension predictions, in that less EMG activity was required to achieve a given supination torque when the forearm was pronated (where biceps brachii is relatively longer). On the other hand, EMG activity of the pronator teres did not decrease when the pronator was lengthened. Triceps EMG was also more active when the forearm was supinated, despite its having no direct functional role in this movement. 6. Plots relating EMG activity in biceps brachii, brachialis, and brachioradialis at three different forearm positions revealed that there was a consistent positive near-linear relationship between brachialis and brachioradialis and that biceps brachii is often most active when brachioradialis and brachialis are least active. 7. We argue that, for the human elbow joint at least, fixed muscle synergies are rather uncommon and that relationships between muscle activities are situation dependent.(ABSTRACT TRUNCATED AT 400 WORDS)

Mechanical Evaluation of the Pronator Teres Rerouting Tendon Transfer

2004 ◽  
Vol 29 (3) ◽  
pp. 257-262 ◽  
Author(s):  
H. E. J. VEEGER ◽  
M. KREULEN ◽  
M. J. C. SMEULDERS
Keyword(s):  
Biceps Brachii ◽  
External Rotation ◽  
Three Dimensional ◽  
Muscle Length ◽  
Biomechanical Model ◽  
Elbow Flexion ◽  
Axial Rotation ◽  
Original Position ◽  
Pronator Quadratus ◽  
Pronator Teres

We simulated pronator teres rerouting using a three-dimensional biomechanical model of the arm. Simulations comprised the evaluation of changes in muscle length and the moment arm of pronator teres with changes in forearm axial rotation and elbow flexion. The rerouting of Pronator Teres was simulated by defining a path for it through the interosseous membrane with re-attachment to its original insertion. However the effect of moving the insertion to new positions, 2 cm below and above, the original position was also assessed. The effect on total internal rotation and external rotation capacity was determined by calculating the potential moments for pronator teres, supinator, pronator quadratus, biceps brachii and brachioradialis. Pronator teres was found to be a weak internal rotator in extreme pronation, but a strong internal rotator in neutral rotation and in supination. After rerouting pronator teres was only a strong external rotator in full pronation and not at other forearm positions, where the effect of rerouting was comparable to a release procedure.

Knowledge of Repetition Range Does Not Affect Maximal Force Production Strategies of Adolescent Females

2017 ◽  
Vol 29 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Jonathan C. Reid ◽  
Rebecca M. Greene ◽  
Nehara Herat ◽  
Daniel D. Hodgson ◽  
Israel Halperin ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Force Production ◽  
Adolescent Females ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Pacing Strategies ◽  
Physiological Reserve ◽  
Random Crossover ◽  
Voluntary Contractions ◽  
Impulse Force

Purpose:Contrary to adult force reserve strategies, it is not known whether adolescent females with less experience performing maximal voluntary contractions (MVC) have specific responses to a known or unknown fatigue endpoint. Methods:Using a counterbalanced random crossover design, fourteen inexperienced female adolescents completed three elbow flexor (EF) fatiguing protocols. Participants were randomly assigned to a control (informed they would perform 12 MVCs), unknown (not informed of the number of MVCs to be completed, but stopped after 12) or deception condition (instructed to complete 6 MVCs, however, after the sixth repetition performed another 6 MVCs). Before and during the interventions, EF impulse, force, and biceps brachii (BB) and triceps brachii (TB) electromyography (EMG) activity were recorded. Results: Participants exhibited decreases in impulse (10.9%; p < .05), force (7.5%; p = .001), BB (16.2%; p < .05) and TB (12.9%; p < .05) EMG activity between the pretest and the first repetition of all protocols. Knowledge of endpoint, or lack of it, did not change measures with the repeated MVCs. When informed about the final repetition, force remained depressed suggesting no physiological reserve. Conclusion:Adolescent females exhibited an anticipatory response to the task of performing repeated MVCs. A lack of change with knowledge of endpoint indicates that those lacking in MVC experience do not employ the same pacing strategies as in previous studies of participants with MVC experience.

scholarly journals Comparison of isometric triceps brachii force measurement in different elbow positions

2018 ◽  
Vol 26 (2) ◽  
pp. 230949901878390
Author(s):  
Ante Prkić ◽  
Jetske Viveen ◽  
Bertram The ◽  
Christiaan JA van Bergen ◽  
Koen LM Koenraadt ◽  
...  
Keyword(s):  
Learning Curve ◽  
Repeated Measures ◽  
Force Measurement ◽  
Intraclass Correlation ◽  
Elbow Extension ◽  
Triceps Brachii ◽  
Flexion Extension ◽  
Extension Force ◽  
Triceps Brachii Muscle ◽  
Test Retest Reliability

Purpose: Objective and reliable force measurement is necessary to monitor the rehabilitation after triceps brachii pathology, injuries, and posterior approach–based surgery. It is unclear at which amount of extension the triceps is best tested and if comparison to the uninjured sided is reliable. This study aims to identify the most reliable elbow position at which elbow extension force is measured using a dynamometer. Furthermore, it aims to compare the extension strength of the dominant arm with that of the nondominant arm. Methods: Isometric elbow extension force of the dominant and nondominant arms of healthy subjects was measured. The measurements were taken in three sequences per arm in 0, 30, 60, 90, and 120 degrees of flexion. A subgroup repeated the measurements to analyze test–retest reliability using intraclass correlation. Results: We included a total of 176 volunteers. The repeated measures analysis of variance for within-subject effect showed the lowest variation coefficient at 30 degrees of flexion. Extension forces showed a mean difference of 3.2–6.9 N in advantage of the dominant arm, resulting in ratios from 1.05 to 1.09. Learning curve analysis showed that during the first session in dominant and nondominant arms, less forces were exerted. Conclusion: The most reliable isometric triceps brachii muscle strength measurement was at 30 degrees of flexion of the elbow. Considering the learning curve, a first tryout session for both arms is indicated. Then, a second measurement suffices as no further learning curve is observed.

scholarly journals Adaptations to cursoriality and digit reduction in the forelimb of the African wild dog (Lycaon pictus)

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9866
Author(s):  
Heather F. Smith ◽  
Brent Adrian ◽  
Rahul Koshy ◽  
Ryan Alwiel ◽  
Aryeh Grossman
Keyword(s):  
Eastern Africa ◽  
Triceps Brachii ◽  
Lycaon Pictus ◽  
Long Distance ◽  
Pronator Quadratus ◽  
Pronator Teres ◽  
Long Distance Running ◽  
Musculoskeletal Anatomy ◽  
African Wild Dog ◽  
Wild Dog

Background The African wild dog (Lycaon pictus), an endangered canid native to southern and eastern Africa, is distinct among canids in being described as entirely tetradactyl and in its nomadic lifestyle and use of exhaustive predation to capture its prey instead of speed, strength, or stealth. These behavioral and morphological traits suggest a potentially unique set of adaptations. Methods Here, we dissected the forelimbs of an adult male L. pictus specimen and performed detailed descriptions and quantitative analyses of the musculoskeletal anatomy. Results Statistical comparisons of muscle masses and volumes revealed that L. pictus has relatively smaller wrist rotators (mm. pronator teres, pronator quadratus, supinator) than any other included carnivoran taxon, suggesting adaptive pressures for antebrachial stability over rotatory movement in the carpus of L. pictus. While a complete digit I is absent in L. pictus, a vestigial first metacarpal was discovered, resulting in changes to insertions of mm. extensor digiti I et II, abductor (et opponens) digiti I and flexor digiti I brevis. Mm. anconeus, brachialis and flexor carpi ulnaris caput ulnare all have more extensive origins in L. pictus than other canids suggesting an emphasis on posture and elbow stability. M. triceps brachii caput laterale has a larger origin in L. pictus and m. triceps brachii caput longum has an additional accessory head. Electromyographic studies have shown this muscle is active during the stance phase of trotting and galloping and is important for storing elastic energy during locomotion. We interpret these differences in size and attachments of muscles in L. pictus as adaptations for long distance running in this highly cursorial species, likely important for exhaustive predation. Absence of a full digit I in L. pictus may increase speed and stride length; however, the retention of a vestigial digit permits the attachment of reduced pollical muscles which may provide additional stability and proprioception to the carpus.

scholarly journals The Excitability of Ipsilateral Motor Evoked Potentials Is Not Task-specific and Spatially Distinct From the Contralateral Motor Hotspot

2022 ◽  
Author(s):  
Nelly Seusing ◽  
Sebastian Strauss ◽  
Robert Fleischmann ◽  
Christina Nafz ◽  
Sergiu Groppa ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Evoked Potentials ◽  
Primary Motor Cortex ◽  
Biceps Brachii ◽  
Motor Evoked Potentials ◽  
Elbow Flexion ◽  
Motor Pathways ◽  
Task Dependence ◽  
Flexion Extension ◽  
Voluntary Contractions

Abstract ObjectiveThe role of ipsilateral descending motor pathways in voluntary movement of humans is still a matter of debate. Few studies have examined the task dependent modulation of ipsilateral motor evoked potentials (iMEPs). Here, we determined the location of upper limb biceps brachii (BB) representation within the ipsilateral primary motor cortex. MethodsMR-navigated transcranial magnetic stimulation mapping of the dominant hemisphere was undertaken with twenty healthy participants who made tonic unilateral, bilateral homologous or bilateral antagonistic elbow flexion-extension voluntary contractions. Map center of gravity (CoG) and area for each BB were obtained. ResultsThe map CoG of the ipsilateral BB was located more anterior-laterally than those of the contralateral BB within the primary motor cortex. However different tasks had no effect on either the iMEP CoG location or the size. ConclusionOur data suggests that ipsilateral and contralateral MEP might originate in distinct adjacent neural populations in the primary motor cortex, independent of task dependence.

scholarly journals High-density surface electromyography signals during isometric contractions of elbow muscles of healthy humans

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Mónica Rojas-Martínez ◽  
Leidy Yanet Serna ◽  
Mislav Jordanic ◽  
Hamid Reza Marateb ◽  
Roberto Merletti ◽  
...  
Keyword(s):  
Upper Limb ◽  
Biceps Brachii ◽  
High Density ◽  
Isometric Contractions ◽  
Myoelectric Activity ◽  
Electrode Arrays ◽  
Triceps Brachii ◽  
Healthy Humans ◽  
Limb Muscles ◽  
Density Surface

AbstractThis paper presents a dataset of high-density surface EMG signals (HD-sEMG) designed to study patterns of sEMG spatial distribution over upper limb muscles during voluntary isometric contractions. Twelve healthy subjects performed four different isometric tasks at different effort levels associated with movements of the forearm. Three 2-D electrode arrays were used for recording the myoelectric activity from five upper limb muscles: biceps brachii, triceps brachii, anconeus, brachioradialis, and pronator teres. Technical validation comprised a signals quality assessment from outlier detection algorithms based on supervised and non-supervised classification methods. About 6% of the total number of signals were identified as “bad” channels demonstrating the high quality of the recordings. In addition, spatial and intensity features of HD-sEMG maps for identification of effort type and level, have been formulated in the framework of this database, demonstrating better performance than the traditional time-domain features. The presented database can be used for pattern recognition and MUAP identification among other uses.

Muscle synergies and isometric torque production: influence of supination and pronation level on elbow flexion

1993 ◽  
Vol 70 (3) ◽  
pp. 947-960 ◽  
Author(s):  
J. C. Jamison ◽  
G. E. Caldwell
Keyword(s):  
Biceps Brachii ◽  
Muscular Activity ◽  
Elbow Flexion ◽  
Normal Subjects ◽  
Analysis Of Covariance ◽  
Triceps Brachii ◽  
Emg Amplitude ◽  
Task Effects ◽  
Long Head ◽  
The Relationship

1. Twenty normal subjects performed a series of isometric elbow flexion (F) maximum voluntary contractions (MVC) while simultaneously maintaining one of seven targeted torque levels in the supination/pronation (S/P) degree of freedom (df). Experimental measures were torque in both df s and surface electromyograms (EMG) from brachioradialis (BRAD), triceps brachii (TB), biceps brachii (BB) short head (BBSH), and a medial and lateral site on biceps brachii long head (MED BB and LAT BB). Task effects were tested for significance using analysis of covariance models for the torque and EMG variables. Polynomial multiple regression models were developed for significant effects. The synergism among muscles was examined by statistically testing the EMG data for differing responses to the S/P torque changes across the five electrode sites. 2. The magnitude of the S/P target torque had a statistically significant effect on flexion MVC (F MVC) torque. Changes in S/P torque markedly influenced the F MVC torque magnitude, with as much as a 25% F torque decrement relative to an F MVC with an S/P torque target of 0. This suggests that the second df task affects some aspect of joint function that causes the CNS to reduce F torque capacity. 3. The S/P torque had a significant effect on EMG amplitude at all electrode sites other than TB. The EMG amplitude at the BB sites responded strongly to both F and S/P torque changes. The F+S tasks tended to facilitate BB EMG, whereas the F+P tasks tended to diminish it. The BRAD EMG, although primarily related to F torque amplitude, also was influenced by the S/P torque changes. The trends for BRAD EMG were opposite those for the BB in that BRAD EMG tended to be enhanced by the F+P tasks and reduced by the F+S tasks. 4. The synergistic pattern of stimulation (i.e., the relationship among the 5 EMG amplitude measures) was also significantly influenced by the S/P df task. Significant differences in the EMG behavior between BBSH and LAT BB were detected; however, no statistically significant differences were found between LAT BB and MED BB. The EMG behaviors at the BRAD and TB electrode sites were significantly different from those at the BB sites. 5. These inversely related responses from the BB and BRAD stress the importance of understanding the relationship between muscular activity and the function of muscles in more than one df. This finding further suggests that the synergistic relationships between muscles are dynamically related to task in all applicable dfs. It is suggested that this dynamic synergism is a natural consequence of the redundant musculoskeletal system.(ABSTRACT TRUNCATED AT 400 WORDS)

An Electromyographic Study of Shoulder Muscles during Bilateral Sanding: A Pilot Study

1981 ◽  
Vol 48 (4) ◽  
pp. 163-168 ◽  
Author(s):  
Anthony R. Newall ◽  
Karen L. Robinson ◽  
Sandi J. Spaulding
Keyword(s):  
Pilot Study ◽  
Biceps Brachii ◽  
Occupational Therapists ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Normal Subject ◽  
Shoulder Muscles ◽  
Shoulder Complex ◽  
Voluntary Contractions ◽  
Therapeutic Activities

Bilateral sanding is used by occupational therapists as a therapeutic exercise technique, however, to-date no data have been available identifying the musculature involved in the activity nor the extent of that involvement. The dual purpose of this pilot study was to; (a) delineate the activity of selected shoulder muscles during bilateral sanding, and (b) determine whether the method used would be feasible in the analysis of other therapeutic activities. For this investigation, a quadriplegic individual was matched for height and weight with a normal subject and both were tested under several controlled conditions of bilateral sanding. Right shoulder complex musculature was electromyographically (EMG) investigated and the muscles studied were: pectoralis major, biceps brachii, the three heads of deltoid, and the lateral and medial heads of triceps brachii. EMG data for the two subjects were normalized and represented as percentages of the maximal voluntary contractions (MVC) relative for each muscle. This technique allowed intra- and inter-subject comparisons of muscle activity. Recognizing the limitations of the study with the major one being the small number of subjects, useful information was obtained from the results. The quadriplegic individual appeared to be more inefficient in his muscle usage than the normal subject. This may be related to trunk instability in the quadriplegic subject. All three heads of the deltoid appeared to be the most highly used of monitored muscles in both the normal and the quadriplegic with triceps being only moderately active in the quadriplegic individual. Spring resisted bilateral sanding produced the most EMG activity in all muscles studied in both subjects. Further investigations employing a larger number of subjects may further elucidate EMG activity during bilateral sanding. It would appear that EMG investigations of therapeutic activities offer an informative method of physical activity analysis.

Arm Posture and Muscular Activity while Inserting and Aiming with Laparoscopic Tools

2005 ◽  
Vol 49 (14) ◽  
pp. 1399-1403
Author(s):  
Trejo, A.E. Jung ◽  
M.S. Hallbeck
Keyword(s):  
Biceps Brachii ◽  
Muscular Activity ◽  
Elbow Flexion ◽  
Dominant Hand ◽  
Wrist Flexion ◽  
Triceps Brachii ◽  
Upper Trapezius ◽  
Flexion Extension ◽  
Laparoscopic Tools ◽  
Wrist Flexors

Two laparoscopic tools, a scissor-type grasper and an ergonomically designed grasper, were compared in terms of arm posture and muscle activity during insertion into a trocar and during a standardized aiming task. Participants were asked to insert a laparoscopic tool into a simulated abdomen and hit five cross-shaped targets using their dominant hand; similar to reaching an organ during laparoscopic surgery. Twenty-six right-handed novice participants volunteered for the study. Two electrogoniometers were used to measure wrist flexion/extension, wrist deviation, and elbow flexion/extension angles. Six surface electrodes were used to measure %MVE of wrist flexors, wrist extensors, biceps brachii, triceps brachii, deltoid, and upper trapezius. The conditions used were five target positions, two touch screen monitor angles, and five hand postures. The scissors-type tool caused the largest wrist flexion, but the smallest %MVE from the wrist flexors. The method of gripping the tools was the most important factor determining joint angles and muscular load during the insertion and aiming tasks.

Sign in / Sign up

Export Citation Format

Share Document