scholarly journals Biceps brachii muscle hardness assessed by a push-in meter in comparison to ultrasound strain elastography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mitsuyoshi Murayama ◽  
Kazunori Nosaka ◽  
Takayuki Inami ◽  
Norihiro Shima ◽  
Tsugutake Yoneda
Keyword(s):  
Biceps Brachii ◽  
Elbow Flexion ◽  
Strain Ratio ◽  
Voluntary Contraction ◽  
Strain Elastography ◽  
Muscle Hardness ◽  
The Relationship ◽  
Force Displacement ◽  
Resting Muscle ◽  
Hardness Values

AbstractThis study investigated the relationship between push-in meter (PM) and ultrasound strain elastography (USE) for biceps brachii (BB) muscle hardness. BB hardness of 21 young men was assessed by PM and USE during rest and isometric contractions of six different intensities (15, 30, 45, 60, 75, 90% of maximal voluntary contraction: MVC) at 30°, 60° and 90° elbow flexion. Muscle hardness (E) was calculated from the force–displacement relationship in PM, and strain ratio (SR) between an acoustic coupler (elastic modulus: 22.6 kPa) and different regions of interest (ROIs) in BB was calculated and converted to Young’s modulus (YM) in USE. In resting muscle, E was 26.1 ± 6.4 kPa, and SR and YM for the whole BB was 0.88 ± 0.4 and 30.8 ± 12.8 kPa, respectively. A significant (p < 0.01) correlation was evident between E and logarithmical transformed SR (LTSR) for the ROI of whole BB (r = − 0.626), and E and converted YM (r = 0.615). E increased approximately ninefold from resting to 90% MVC, and E and LTSR (r = − 0.732 to − 0.880), and E and converted YM for the SR above 0.1 were correlated (r = 0.599–0.768, p < 0.01). These results suggest that muscle hardness values obtained by PM and USE are comparable.

scholarly journals Reliability of Trapezius Muscle Hardness Measurement: A Comparison between Portable Muscle Hardness Meter and Ultrasound Strain Elastography

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7200
Author(s):  
Tomonori Sawada ◽  
Hiroki Okawara ◽  
Daisuke Nakashima ◽  
Shuhei Iwabuchi ◽  
Morio Matsumoto ◽  
...  
Keyword(s):  
Trapezius Muscle ◽  
Hardness Measurement ◽  
Strain Ratio ◽  
Muscle Stiffness ◽  
Computer Work ◽  
Shoulder Stiffness ◽  
Strain Elastography ◽  
Upper Trapezius ◽  
Muscle Hardness ◽  
Hardness Values

Prolonged computer work and smartphone use can cause stiffness of the neck and shoulder muscles, including the trapezius muscle. Hence, muscle hardness quantification is clinically beneficial. The present study aimed to examine the reliability of trapezius muscle hardness measurement using a portable muscle hardness meter and ultrasound strain elastography. Overall, 20 healthy young men participated in this study. Prior to measurement, the participant’s subjective symptoms, particularly shoulder muscle stiffness, were rated using an 11-point verbal scale. Furthermore, hardness of the right and left upper trapezius muscles was assessed. In the strain elastography assessment, muscle hardness was evaluated using strain ratio. Results showed that, in quantifying upper trapezius muscle hardness, both portable muscle hardness meter and strain elastography had an excellent intra-tester reliability (>0.9). However, the correlation coefficients between muscle hardness values assessed using a muscle hardness meter and those evaluated with strain elastography did not significantly differ, and the scores for subjective shoulder stiffness did not correspond to muscle hardness values. Therefore, the hardness of the trapezius muscle does not directly reflect the subjective shoulder stiffness. Future studies should thoroughly examine the location of the shoulder stiffness, and check whether it is accompanied by local pain or tenderness.

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)

The Effects of Red Versus Blue Lights and Neuroticism on Voluntary Biceps Brachii Muscle Contraction

2019 ◽  
Vol 126 (2) ◽  
pp. 253-266
Author(s):  
Erdal Binboğa ◽  
Serdar Tok ◽  
Mustafa Munzuroğlu ◽  
Aykut Eren Canüzmez ◽  
Nihal Dal
Keyword(s):  
Blue Light ◽  
Biceps Brachii ◽  
Red Light ◽  
Light Condition ◽  
Elbow Flexion ◽  
Voluntary Contraction ◽  
Biceps Brachii Muscle ◽  
Personality Differences ◽  
Individual Personality ◽  
Median Split

This study investigated the effects of red and blue monochromatic lights and neuroticism on athletes’ maximal isometric voluntary contraction (iMVC) level of the biceps brachii muscle. During elbow flexion, we measured iMVCs under a white light (control) condition and under red and blue light conditions. Under red light (vs. white and blue), participants demonstrated a greater iMVC level. Further, based on a median split of the athletes’ scores on Tatar’s Five Factor Personality Inventory, high and low neuroticism groups showed no red light differences, while, in the blue light condition, participants high in neuroticism increased the iMVC level by 4.04% and those low in neuroticism decreased iMVC level by 6.31%. Thus, the effect of colored light on athletes’ motor output varied with individual personality differences in neuroticism.

scholarly journals Relationship between Isometric Muscle Force and Fractal Dimension of Surface Electromyogram

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Matteo Beretta-Piccoli ◽  
Gennaro Boccia ◽  
Tessa Ponti ◽  
Ron Clijsen ◽  
Marco Barbero ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Muscle Contraction ◽  
Biceps Brachii ◽  
Isometric Force ◽  
Voluntary Contraction ◽  
Experimental Conditions ◽  
Surface Electromyogram ◽  
Mean Frequency ◽  
Muscle Contraction Intensity ◽  
The Relationship

The relationship between fractal dimension of the surface electromyogram (sEMG) and the intensity of muscle contraction is still controversial in simulated and experimental conditions. To support the use of fractal analysis to investigate myoelectric fatigue, it is crucial to establish the interdependence between fractal dimension and muscle contraction intensity. We analyzed the behavior of fractal dimension, conduction velocity, mean frequency, and average rectified value in twenty-eight volunteers at nine levels of isometric force. sEMG was obtained using bidimensional arrays in the biceps brachii muscle. The values of fractal dimension and mean frequency increased with force unless a plateau was reached at 30% maximal voluntary contraction. Overall, our findings suggest that, above a certain level of force, the use of fractal dimension to evaluate the myoelectric manifestations of fatigue may be considered, regardless of muscle contraction intensity.

scholarly journals Modulation of transcallosal inhibition by bilateral activation of agonist and antagonist proximal arm muscles

2014 ◽  
Vol 111 (2) ◽  
pp. 405-414 ◽  
Author(s):  
Monica A. Perez ◽  
Jane E. Butler ◽  
Janet L. Taylor
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Motor Behavior ◽  
Biceps Brachii ◽  
Silent Period ◽  
Elbow Flexion ◽  
Voluntary Contraction ◽  
Triceps Brachii ◽  
Transcallosal Inhibition ◽  
Flexion Extension

Transcallosal inhibitory interactions between proximal representations in the primary motor cortex remain poorly understood. In this study, we used transcranial magnetic stimulation to examine the ipsilateral silent period (iSP; a measure of transcallosal inhibition) in the biceps and triceps brachii during unilateral and bilateral isometric voluntary contractions. Healthy volunteers performed 10% of maximal isometric voluntary elbow flexion or extension with one arm while the contralateral arm remained at rest or performed 30% of maximal isometric voluntary elbow flexion or extension. The iSP was measured in the arm performing 10% contractions, and electromyographic (EMG) recordings were comparable across conditions. The iSP onset and duration in the biceps and triceps brachii were comparable. In both muscles, the iSP depth and area were increased during bilateral contractions of homologous agonist muscles (extension-extension and flexion-flexion) compared with a unilateral contraction, whereas during bilateral contractions of nonhomologous antagonist muscles (extension-flexion and flexion-extension), the iSP depth and area were decreased compared with a unilateral contraction, and sometimes facilitation of EMG was seen. This effect was never observed during bilateral activation of homologous muscles. The size of responses evoked by cervicomedullary electrical stimulation in the arm that made 10% contractions remained unchanged across conditions. Thus transcallosal inhibition targeting triceps and biceps brachii is upregulated by voluntary contraction of the contralateral agonist muscle and downregulated by voluntary contraction of the contralateral antagonist muscle. We speculate that these reciprocal task-dependent interactions between bilateral flexor and extensor arm regions of the motor cortex may contribute to coupling between the arms during motor behavior.

scholarly journals Independence Between Two Channels of Surface Electromyogram Signal to Measure the Loss of Motor Units

2015 ◽  
Vol 15 (3) ◽  
pp. 152-155 ◽  
Author(s):  
Sridhar P. Arjunan ◽  
Dinesh Kumar ◽  
Ganesh Naik
Keyword(s):  
Biceps Brachii ◽  
Motor Units ◽  
Voluntary Contraction ◽  
Frobenius Norm ◽  
Semg Signal ◽  
Surface Electromyogram ◽  
Isometric Muscle Contraction ◽  
Age Range ◽  
The Relationship ◽  
Surface Electromyogram Signal

AbstractThis study has investigated the relationship in the connectivity of motor units in surface electromyogram (sEMG) of biceps brachii muscle. It is hypothesized that with ageing, there is reduction/loss in number of motor units, leading to reduction in the independence between the channels of the recorded muscle activity. Two channels of sEMG were recorded during three levels of isometric muscle contraction: 50 %, 75 % and 100 % maximal voluntary contraction (MVC). 73 subjects (age range 20-70) participated in the experiments. The independence in channel index (ICI) between the two sEMG recording locations was computed using the independent components and Frobenius norm. ANOVA Statistical analysis was performed to test the effect of age (loss of motor units) and level of contraction on ICI. The results show that the ICI among the older cohort was significantly lower compared with the younger adults. This research study has shown that the reduction in number of motor units is reflected by the reduction in the ICI of the sEMG signal.

Nonuniform shortening in the biceps brachii during elbow flexion

2002 ◽  
Vol 92 (6) ◽  
pp. 2381-2389 ◽  
Author(s):  
George P. Pappas ◽  
Deanna S. Asakawa ◽  
Scott L. Delp ◽  
Felix E. Zajac ◽  
John E. Drace
Keyword(s):  
Biceps Brachii ◽  
Maximum Voluntary Contraction ◽  
Elbow Flexion ◽  
Longitudinal Axis ◽  
Distal Region ◽  
Voluntary Contraction ◽  
Common Assumption ◽  
Contrast Magnetic Resonance ◽  
Muscle Fascicles ◽  
Cine Phase Contrast

This study tested the common assumption that skeletal muscle shortens uniformly in the direction of its fascicles during low-load contraction. Cine phase contrast magnetic resonance imaging was used to characterize shortening of the biceps brachii muscle in 12 subjects during repeated elbow flexion against 5 and 15% maximum voluntary contraction (MVC) loads. Mean shortening was relatively constant along the anterior boundary of the muscle and averaged 21% for both loading conditions. In contrast, mean shortening was nonuniform along the centerline of the muscle during active elbow flexion. Centerline shortening in the distal region of the biceps brachii (7.3% for 5% MVC and 3.7% for 15% MVC) was significantly less ( P < 0.001) than shortening in the muscle midportion (26.3% for 5% MVC and 28.2% for 15% MVC). Nonuniform shortening along the centerline was likely due to the presence of an internal aponeurosis that spanned the distal third of the longitudinal axis of the biceps brachii. However, muscle shortening was also nonuniform proximal to the centerline aponeurosis. Because muscle fascicles follow the anterior contour and centerline of the biceps brachii, our results suggest that shortening is uniform along anterior muscle fascicles and nonuniform along centerline fascicles.

scholarly journals Muscle length and joint angle influence spinal but not corticospinal excitability to the biceps brachii across forearm postures

2019 ◽  
Vol 122 (1) ◽  
pp. 413-423 ◽  
Author(s):  
Davis A. Forman ◽  
Daniel Abdel-Malek ◽  
Christopher M. F. Bunce ◽  
Michael W. R. Holmes
Keyword(s):  
Isometric Contraction ◽  
Elbow Joint ◽  
Joint Angle ◽  
Biceps Brachii ◽  
Motor Evoked Potentials ◽  
Muscle Length ◽  
Elbow Flexion ◽  
Corticospinal Excitability ◽  
Biceps Brachii Muscle ◽  
Spinal Excitability

Forearm rotation (supination/pronation) alters corticospinal excitability to the biceps brachii, but it is unclear whether corticospinal excitability is influenced by joint angle, muscle length, or both. Thus the purpose of this study was to separately examine elbow joint angle and muscle length on corticospinal excitability. Corticospinal excitability to the biceps and triceps brachii was measured using motor evoked potentials (MEPs) elicited via transcranial magnetic stimulation. Spinal excitability was measured using cervicomedullary motor evoked potentials (CMEPs) elicited via transmastoid electrical stimulation. Elbow angles were manipulated with a fixed biceps brachii muscle length (and vice versa) across five unique postures: 1) forearm neutral, elbow flexion 90°; 2) forearm supinated, elbow flexion 90°; 3) forearm pronated, elbow flexion 90°; 4) forearm supinated, elbow flexion 78°; and 5) forearm pronated, elbow flexion 113°. A musculoskeletal model determined biceps brachii muscle length for postures 1–3, and elbow joint angles ( postures 4–5) were selected to maintain biceps length across forearm orientations. MEPs and CMEPs were elicited at rest and during an isometric contraction of 10% of maximal biceps muscle activity. At rest, MEP amplitudes to the biceps were largest during supination, which was independent of elbow joint angle. CMEP amplitudes were not different when the elbow was fixed at 90° but were largest in pronation when muscle length was controlled. During an isometric contraction, there were no significant differences across forearm postures for either MEP or CMEP amplitudes. These results highlight that elbow joint angle and biceps brachii muscle length can each independently influence spinal excitability. NEW & NOTEWORTHY Changes in upper limb posture can influence the responsiveness of the central nervous system to artificial stimulations. We established a novel approach integrating neurophysiology techniques with biomechanical modeling. Through this approach, the effects of elbow joint angle and biceps brachii muscle length on corticospinal and spinal excitability were assessed. We demonstrate that spinal excitability is uniquely influenced by joint angle and muscle length, and this highlights the importance of accounting for muscle length in neurophysiological studies.

Intramuscular and surface electromyogram changes during muscle fatigue

1986 ◽  
Vol 60 (4) ◽  
pp. 1179-1185 ◽  
Author(s):  
T. Moritani ◽  
M. Muro ◽  
A. Nagata
Keyword(s):  
Muscle Fatigue ◽  
Biceps Brachii ◽  
Surface Emg ◽  
Firing Frequency ◽  
Voluntary Contraction ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Surface Electromyogram ◽  
Spike Amplitude ◽  
Frequency Power

Twelve male subjects were tested to determine the effects of motor unit (MU) recruitment and firing frequency on the surface electromyogram (EMG) frequency power spectra during sustained maximal voluntary contraction (MVC) and 50% MVC of the biceps brachii muscle. Both the intramuscular MU spikes and surface EMG were recorded simultaneously and analyzed by means of a computer-aided intramuscular spike amplitude-frequency histogram and frequency power spectral analysis, respectively. Results indicated that both mean power frequency (MPF) and amplitude (rmsEMG) of the surface EMG fell significantly (P less than 0.001) together with a progressive reduction in MU spike amplitude and firing frequency during sustained MVC. During 50% MVC there was a significant decline in MPF (P less than 0.001), but this decline was accompanied by a significant increase in rmsEMG (P less than 0.001) and a progressive MU recruitment as evidenced by an increased number of MUs with relatively large spike amplitude. Our data suggest that the surface EMG amplitude could better represent the underlying MU activity during muscle fatigue and the frequency powers spectral shift may or may not reflect changes in MU recruitment and rate-coding patterns.

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.

Sign in / Sign up

Export Citation Format

Share Document