Crosstalk in Mechanomyographic Signals From Elbow Flexor Muscles During Submaximal to Maximal Isometric Flexion, Pronation, and Supination Torque Tasks

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Irsa Talib ◽  
Kenneth Sundaraj ◽  
Chee Kiang Lam
Keyword(s):  
Biceps Brachii ◽  
Elbow Flexion ◽  
Fiber Axis ◽  
Maximum Voluntary Isometric Contraction ◽  
High Positive Correlation ◽  
Flexor Muscles ◽  
Positive Correlations ◽  
Muscle Actions ◽  
Level Of Effort ◽  
Isometric Muscle

Abstract This study analyzed the crosstalk in mechanomyographic (MMG) signals from elbow flexors during isometric muscle actions from 20% to 100% maximum voluntary isometric contraction (MVIC). Twenty-five young, healthy, male participants performed the isometric elbow flexion, forearm pronation, and supination tasks at an elbow joint angle of 90 deg. The MMG signals from the biceps brachii (BB), brachialis (BRA), and brachioradialis (BRD) muscles were recorded using accelerometers. The cross-correlation coefficient was used to quantify the crosstalk in MMG signals, recorded in a direction transverse to muscle fiber axis, among the muscle pairs (P1: BB and BRA, P2: BRA and BRD, and P3: BB and BRD). In addition, the MMG RMS and MPF were quantified. The mean normalized RMS and mean MPF exhibited increasing (r > 0.900) and decreasing (r < −0.900) trends, respectively, with increases in the effort levels in all three tasks. The magnitude of crosstalk ranged from 0.915% to 21.565% in all three muscle pairs. The crosstalk was found to exhibit high positive correlations with submaximal to maximal flexion [P1 (r = 0.970), P2 (r = 0.951), and P3 (r = 0.824)], pronation [P1 (r = 0.811), P2 (r = 0.763), and P3 (r = 0.901)] and supination [P1 (r = 0.898), P2 (r = 0.838), and P3 (r = 0.852)] torque levels (eight out of nine p-values were < 0.05). Regardless of the high positive correlation between crosstalk and level of effort, the crosstalk remained at a low range (0.915–21.565%) with increases in the torque levels.

scholarly journals Muscle Oxygenation Level Might Trigger the Regulation of Capillary Venous Blood Filling during Fatiguing Isometric Muscle Actions

Diagnostics ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1973
Author(s):  
Silas Dech ◽  
Frank N. Bittmann ◽  
Laura V. Schaefer
Keyword(s):  
Venous Blood ◽  
Elbow Flexion ◽  
Type I ◽  
Type Ii ◽  
Maximal Voluntary Isometric Contraction ◽  
Behavioral Types ◽  
Blood Filling ◽  
Oxygenation Level ◽  
Muscle Actions ◽  
Isometric Muscle

The regulation of oxygen and blood supply during isometric muscle actions is still unclear. Recently, two behavioral types of oxygen saturation (SvO2) and relative hemoglobin amount (rHb) in venous microvessels were described during a fatiguing holding isometric muscle action (HIMA) (type I: nearly parallel behavior of SvO2 and rHb; type II: partly inverse behavior). The study aimed to ascertain an explanation of these two regulative behaviors. Twelve subjects performed one fatiguing HIMA trial with each arm by weight holding at 60% of the maximal voluntary isometric contraction (MVIC) in a 90° elbow flexion. Six subjects additionally executed one fatiguing PIMA trial by pulling on an immovable resistance with 60% of the MVIC with each side and same position. Both regulative types mentioned were found during HIMA (I: n = 7, II: n = 17) and PIMA (I: n = 3, II: n = 9). During the fatiguing measurements, rHb decreased initially and started to increase in type II at an average SvO2-level of 58.75 ± 2.14%. In type I, SvO2 never reached that specific value during loading. This might indicate the existence of a threshold around 59% which seems to trigger the increase in rHb and could explain the two behavioral types. An approach is discussed to meet the apparent incompatibility of an increased capillary blood filling (rHb) despite high intramuscular pressures which were found by other research groups during isometric muscle actions.

scholarly journals Association of anthropometric parameters with amplitude and crosstalk of mechanomyographic signals during forearm flexion, pronation and supination torque tasks

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Irsa Talib ◽  
Kenneth Sundaraj ◽  
Chee Kiang Lam
Keyword(s):  
Biceps Brachii ◽  
Correlation Coefficients ◽  
Skinfold Thickness ◽  
Voluntary Contraction ◽  
Anthropometric Parameters ◽  
Arm Circumference ◽  
Human Arm ◽  
Flexor Muscles ◽  
Positive Correlations ◽  
Almost All

Abstract This study aimed to quantify the association of four anthropometric parameters of the human arm, namely, the arm circumference (CA), arm length (LA), skinfold thickness (ST) and inter-sensor distance (ISD), with amplitude (RMS) and crosstalk (CT) of mechanomyography (MMG) signals. Twenty-five young, healthy, male participants were recruited to perform forearm flexion, pronation and supination torque tasks. Three accelerometers were employed to record the MMG signals from the biceps brachii (BB), brachialis (BRA) and brachioradialis (BRD) at 80% maximal voluntary contraction (MVC). Signal RMS was used to quantify the amplitude of the MMG signals from a muscle, and cross-correlation coefficients were used to quantify the magnitude of the CT among muscle pairs (BB & BRA, BRA & BRD, and BB & BRD). For all investigated muscles and pairs, RMS and CT showed negligible to low negative correlations with CA, LA and ISD (r = −0.0001–−0.4611), and negligible to moderate positive correlations with ST (r = 0.004–0.511). However, almost all of these correlations were statistically insignificant (p > 0.05). These findings suggest that RMS and CT values for the elbow flexor muscles recorded and quantified using accelerometers appear invariant to anthropometric parameters.

Gender Comparisons of Mechanomyographic Amplitude and Mean Power Frequency versus Isometric Torque Relationships

2005 ◽  
Vol 21 (1) ◽  
pp. 96-109 ◽  
Author(s):  
Travis W. Beck ◽  
Terry J. Housh ◽  
Glen O. Johnson ◽  
Joseph P. Weir ◽  
Joel T. Cramer ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Maximum Voluntary Contraction ◽  
Fluid Pressure ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Power Frequency ◽  
Isometric Torque ◽  
Muscle Actions ◽  
Best Fit ◽  
Isometric Muscle

This study compared the patterns of mechanomyographic (MMG) amplitude and mean power frequency vs. torque relationships in men and women during isometric muscle actions of the biceps brachii. Seven men (mean age 23.9 ± 3.5 yrs) and 8 women (mean 21.0 ± 1.3 yrs) performed submaximal to maximal isometric muscle actions of the dominant forearm flexors. Following determination of the isometric maximum voluntary contraction (MVC), they randomly performed submaximal step muscle actions in 10% increments from 10% to 90% MVC. Polynomial regression analyses indicated that the MMG amplitude vs. isometric torque relationship for the men was best fit with a cubic model (R2= 0.983), where MMG amplitude increased slightly from 10% to 20% MVC, increased rapidly from 20% to 80% MVC, and plateaued from 80% to 100% MVC. For the women, MMG amplitude increased linearly (r2= 0.949) from 10% to 100% MVC. Linear models also provided the best fit for the MMG mean power frequency vs. isometric torque relationship in both the men (r2= 0.813) and women (r2= 0.578). The results demonstrated gender differences in the MMG amplitude vs. isometric torque relationship, but similar torque-related patterns for MMG mean power frequency. These findings suggested that the plateau in MMG amplitude at high levels of isometric torque production for the biceps brachii in the men, but not the women, may have been due to greater isometric torque, muscle stiffness, and/or intramuscular fluid pressure in the men, rather than to differences in motor unit activation strategies for modulating isometric torque production.

scholarly journals Behavior of oxygen saturation and blood filling in the venous capillary system of the biceps brachii muscle during a fatiguing isometric action

2020 ◽  
Vol 30 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Silas Dech ◽  
Frank Bittmann ◽  
Laura Schaefer
Keyword(s):  
Steady State ◽  
Oxygen Saturation ◽  
Biceps Brachii ◽  
Rank Correlation ◽  
Type I ◽  
Type Ii ◽  
Venous Oxygen Saturation ◽  
Capillary Circulation ◽  
Muscle Actions ◽  
Isometric Muscle

The objective of the study is to develop a better understanding of the capillary circulation in contracting muscles. Ten subjects were measured during a submaximal fatiguing isometric muscle action by use of the O2C spectrophotometer. In all measurements the capillary-venous oxygen saturation of hemoglobin (SvO2) decreases immediately after the start of loading and levels off into a steady state. However, two different patterns (type I and type II) emerged. They differ in the extent of deoxygenation (–10.37 ±2.59 percent points (pp) vs. –33.86 ±17.35 pp, P = .008) and the behavior of the relative hemoglobin amount (rHb). Type I reveals a positive rank correlation of SvO2 and rHb (ρ = 0.735, P <.001), whereas a negative rank correlation (ρ = –0.522, P <.001) occurred in type II, since rHb decreases until a reversal point, then increases averagely 13% above the baseline value and levels off into a steady state. The results reveal that a homeostasis of oxygen delivery and consumption during isometric muscle actions is possible. A rough distinction in two types of regulation is suggested.

THE EFFECT OF DEHYDRATION ON TORQUE AND MECHANOMYOGRAPHY DURING ISOMETRIC MUSCLE ACTIONS OF THE BICEPS BRACHII

2001 ◽  
Vol 33 (5) ◽  
pp. S335
Author(s):  
J T. Soukup ◽  
S M. Drake ◽  
J C. Boyd ◽  
L C. Eschbach ◽  
M T. Whitehead ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Muscle Actions ◽  
Isometric Muscle

scholarly journals Effect of Resonant Frequency Vibration on Delayed Onset Muscle Soreness and Resulting Stiffness as Measured by Shear-Wave Elastography

2021 ◽  
Vol 18 (15) ◽  
pp. 7853
Author(s):  
Garrett C. Jones ◽  
Jonathan D. Blotter ◽  
Cameron D. Smallwood ◽  
Dennis L. Eggett ◽  
Darryl J. Cochrane ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Shear Wave ◽  
Time Course ◽  
Biceps Brachii ◽  
Shear Wave Elastography ◽  
Upper Body ◽  
Maximum Voluntary Isometric Contraction ◽  
Post Exercise ◽  
Significant Difference ◽  
Pain Ratings

This study utilized resonant frequency vibration to the upper body to determine changes in pain, stiffness and isometric strength of the biceps brachii after eccentric damage. Thirty-one participants without recent resistance training were randomized into three groups: a Control (C) group and two eccentric exercise groups (No vibration (NV) and Vibration (V)). After muscle damage, participants in the V group received upper body vibration (UBV) therapy for 5 min on days 1–4. All participants completed a visual analog scale (VAS), maximum voluntary isometric contraction (MVIC), and shear wave elastography (SWE) of the bicep at baseline (pre-exercise), 24 h, 48 h, and 1-week post exercise. There was a significant difference between V and NV at 24 h for VAS (p = 0.0051), at 24 h and 1-week for MVIC (p = 0.0017 and p = 0.0016, respectively). There was a significant decrease in SWE for the V group from 24–48 h (p = 0.0003), while there was no significant change in the NV group (p = 0.9341). The use of UBV resonant vibration decreased MVIC decrement and reduced VAS pain ratings at 24 h post eccentric damage. SWE was strongly negatively correlated with MVIC and may function as a predictor of intrinsic muscle state in the time course of recovery of the biceps brachii.

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.

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