Elastic kirigami patch for electromyographic analysis of the palm muscle during baseball pitching

Abstract Surface electromyography (sEMG) is widely used to analyze human movements, including athletic performance. For baseball pitchers, a very precise movement is required to pitch the ball into the strike zone. The palm muscles appear to play a key role in this movement, and a real-time recording of sEMG from the palm muscle is useful in the analysis of motion during baseball pitching. However, the currently available devices with rigid and bulky electrodes (including connective wires) impede natural movements of the wearer and recording of sEMG from the palm muscles during vigorous action. Here, we describe a skin-contact patch consisting of kirigami-based stretchable wirings and conductive polymer nanosheet-based ultraconformable bioelectrodes, which address the challenge of mechanical mismatch between human skin and electrical devices. The key strategy is a kirigami-inspired wiring design and a mechanical gradient structure from nanosheet-based flexible bioelectrodes to a bulk wearable device. This approach would buffer the mechanical stress applied to the skin-contact bioelectrodes during an arm swing movement. With this patch, we precisely measure sEMG at the abductor pollicis brevis muscle (APBM) in a baseball player during ball pitching. We observe differences in the activity of the APBM between different types of pitches—fastball and curveball. This sEMG measurement system will enable the analysis of motion in unexplored muscle areas, such as on the palm and the sole, leading to a deeper understanding of muscular activity during performance in a wide range of sports and other movements.

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A method to construct the dynamic landscape of a bio-membrane with experiment and simulation

Nature Communications ◽

10.1038/s41467-021-27417-y ◽

2022 ◽

Vol 13 (1) ◽

Author(s):

Albert A. Smith ◽

Alexander Vogel ◽

Oskar Engberg ◽

Peter W. Hildebrand ◽

Daniel Huster

Keyword(s):

Molecular Dynamics ◽

Nmr Relaxation ◽

Dynamics Simulation ◽

Comprehensive Description ◽

Correlation Times ◽

Wide Range ◽

Dynamic Landscape ◽

C Nmr ◽

Analysis Of Motion

AbstractBiomolecular function is based on a complex hierarchy of molecular motions. While biophysical methods can reveal details of specific motions, a concept for the comprehensive description of molecular dynamics over a wide range of correlation times has been unattainable. Here, we report an approach to construct the dynamic landscape of biomolecules, which describes the aggregate influence of multiple motions acting on various timescales and on multiple positions in the molecule. To this end, we use 13C NMR relaxation and molecular dynamics simulation data for the characterization of fully hydrated palmitoyl-oleoyl-phosphatidylcholine bilayers. We combine dynamics detector methodology with a new frame analysis of motion that yields site-specific amplitudes of motion, separated both by type and timescale of motion. In this study, we show that this separation allows the detailed description of the dynamic landscape, which yields vast differences in motional amplitudes and correlation times depending on molecular position.

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A Study of Thermal Stability and Electromaganetic Shielding Behavior of Polyaniline-P-Toluene Sulfonic Acid/Montmorillonite Nanocomposites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.52-54.180 ◽

2011 ◽

Vol 52-54 ◽

pp. 180-185 ◽

Cited By ~ 1

Author(s):

Ming Kuen Chang ◽

Hsin Hong Hsieh ◽

Siou Jyuan Li

Keyword(s):

Thermal Stability ◽

Electromagnetic Interference ◽

Conductive Polymer ◽

Layered Silicate ◽

Electromagnetic Shielding ◽

Environmental Stability ◽

Shielding Effectiveness ◽

Increase With Increase ◽

Toluene Sulfonic Acid ◽

Wide Range

Intrinsically conductive polymer-Polyaniline had high conductivity and many other properties, such as environmental stability and rather simple synthesis. In addition, doping with organic acids could enhance its processing, so it had wide range of applications, such as solar cells, antistatic and electromagnetic interference shielding. In this study, the organic amine 1-Dodecylamine (DOA) modification of sodium montmorillonite (NA+-MMT), and conducting polymer / layered silicate salt nanocomposites (PANI-PTSA/DOA-MMT) had been prepared by doping aniline with organic acid (PTSA), then added organic clay. The thermal, electrical properties and EMI effects of nanocomposites had discussed by XRD, TEM, EMI, TGA analysis, conduction measure and EMI tested. The results indicated the organo-clay interlayer distance expanded from 1.29 to 1.8 nm, and DOA-MMT dispersed in the material, that formed an exfoliated nanocomposite. The thermal stability of nanocomposites depended on content of DOA-MMT, material had the better thermal stability when DOA-MMT load was 5 wt. %. The nanocomposites had the best conductivity when DOA-MMT load was 1 wt. % as well as the electromagnetic shielding effectiveness was increase with increase in conductivity. In addition, the electromagnetic shielding of nanocomposites also depended on thickness and frequency of electromagnetic wave, the electromagnetic shielding was increased with increase in thickness and frequency.

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The Pattern of Muscular Activity During the Arm Swing of Natural Walking

Acta Physiologica Scandinavica ◽

10.1111/j.1748-1716.1965.tb04069.x ◽

1965 ◽

Vol 63 (3) ◽

pp. 296-310 ◽

Cited By ~ 89

Author(s):

Maria L. Fernandez Ballesteros ◽

Fritz Buchthal ◽

Poul Rosenfalck

Keyword(s):

Muscular Activity ◽

Arm Swing

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Dynamic Modulation of Beta Band Cortico-Muscular Coupling Induced by Audio–Visual Rhythms

Cerebral Cortex Communications ◽

10.1093/texcom/tgaa043 ◽

2020 ◽

Vol 1 (1) ◽

Cited By ~ 1

Author(s):

Manuel Varlet ◽

Sylvie Nozaradan ◽

Laurel Trainor ◽

Peter E Keller

Keyword(s):

Muscular Activity ◽

Force Sensor ◽

Underlying Mechanism ◽

Beta Band ◽

Motor Systems ◽

Dynamic Modulation ◽

Behavioral Studies ◽

Human Movements ◽

Movement Frequency ◽

Finger Pressure

Abstract Human movements often spontaneously fall into synchrony with auditory and visual environmental rhythms. Related behavioral studies have shown that motor responses are automatically and unintentionally coupled with external rhythmic stimuli. However, the neurophysiological processes underlying such motor entrainment remain largely unknown. Here, we investigated with electroencephalography (EEG) and electromyography (EMG) the modulation of neural and muscular activity induced by periodic audio and/or visual sequences. The sequences were presented at either 1 or 2 Hz, while participants maintained constant finger pressure on a force sensor. The results revealed that although there was no change of amplitude in participants’ EMG in response to the sequences, the synchronization between EMG and EEG recorded over motor areas in the beta (12–40 Hz) frequency band was dynamically modulated, with maximal coherence occurring about 100 ms before each stimulus. These modulations in beta EEG–EMG motor coherence were found for the 2-Hz audio–visual sequences, confirming at a neurophysiological level the enhancement of motor entrainment with multimodal rhythms that fall within preferred perceptual and movement frequency ranges. Our findings identify beta band cortico-muscular coupling as a potential underlying mechanism of motor entrainment, further elucidating the nature of the link between sensory and motor systems in humans.

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An Electromyographic Analysis of Muscular Activity in the Hindlimb of the Cat during Unrestrained Locomotion

Acta Physiologica Scandinavica ◽

10.1111/j.1748-1716.1969.tb04415.x ◽

1969 ◽

Vol 75 (4) ◽

pp. 614-630 ◽

Cited By ~ 326

Author(s):

I. Engberg ◽

A. Lundberg

Keyword(s):

Muscular Activity ◽

Electromyographic Analysis

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The Speed–Accuracy Tradeoff as a Subject of Psychological Analysis

Bulletin of Kemerovo State University ◽

10.21603/2078-8975-2021-23-1-123-132 ◽

2021 ◽

Vol 23 (1) ◽

pp. 123-132

Author(s):

D. Yu. Balanev ◽

E. V. Bredun

Keyword(s):

Cognitive Strategies ◽

Fine Motor ◽

Professional Status ◽

Target Area ◽

Target Time ◽

Psychological Analysis ◽

Human Movements ◽

Wide Range ◽

Speed Accuracy ◽

Accuracy Tradeoff

The present research featured the regularities, according to which the accuracy of human movements is associated with the length of these movements and time. The author considered the speed–accuracy tradeoff problem by analyzing the procedural aspect of cognitive performance. The experiment included more than a thousand participants and was performed on a portable touch screen device that tested the subject's attitude to solving problems in terms of speed or accuracy. The research objective was to identify significantly different ways of solving the speed–accuracy tradeoff dilemma. At the fine motor level, the participants failed to accomplish a one-to-one correspondence between target area and target time. This ambiguity was a manifestation of various cognitive strategies for performing a speed–accuracy tradeoff task. The Fitts law violations were determined using a wide range of statistical methods and manifested themselves at the level of criteria analysis for the normality of data distribution, types of variance analysis, and multivariate data analysis. The cluster analysis could register various strategies for performing the speed–accuracy tradeoff task. Additional variables, e.g. professional status of the subjects, made it possible to interpret the differences according to specific skills in solving cognitive tasks and to clarify the nature of these skills.

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Flexible Cellulose-Based Assembled with PEDOT: PSS Electrodes for ECG Monitoring

10.21203/rs.3.rs-207155/v1 ◽

2021 ◽

Author(s):

Yanping Wang ◽

Xing Zhong ◽

Wei Wang ◽

Dan Yu

Keyword(s):

Polyvinyl Alcohol ◽

Composite Electrode ◽

Low Cost ◽

Oxidative Polymerization ◽

Crosslinking Agent ◽

Conductive Polymer ◽

Environmentally Friendly ◽

Contact Impedance ◽

Ecg Signals ◽

Skin Contact

Abstract Electrocardiography is one of the most significant technologies for detecting cardiovascular diseases. Nowadays, the problems of various electrodes still meet a great challenge. Herein, we design a low cost, environmentally friendly and flexible conductive electrode using cellulose and polyvinyl alcohol as a substrate assembled with conductive polymer polythiophene by in-situ oxidative polymerization, and the green solvent 1-butyl-3-methylimidazolium chloride as a crosslinking agent. The polyvinyl alcohol/cellulose/PEDOT:PSS(PCPP) composite electrode has excellent features of flexibility, low skin contact impedance and comfortable contact with skin. When the load of EDOT reaches 15 wt%, the electrode is stable and can clearly monitor the characteristic wave of ECG signals. Therefore, based on cellulosic biopolymer and conductive polymer PEDOT:PSS, an environmentally friendly, flexible and stable PCPP composite electrode is obtained and can be a promising candidate applied in the fields of energy storage and ECG sensing.

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PECULIARITIES OF THE FACTOR STRUCTURE OF PHYSICAL WORKING CAPACITY IN BOYS AND GIRLS AGED OF 9-10 YEARS

Hygiene and Sanitation ◽

10.18821/0016-9900-2017-96-8-759-765 ◽

2019 ◽

Vol 96 (8) ◽

pp. 759-765 ◽

Cited By ~ 2

Author(s):

Igor A. Krivolapchuk ◽

V. V. Myshyakov

Keyword(s):

Physical Performance ◽

Anaerobic Power ◽

Muscular Activity ◽

Physical Working Capacity ◽

Working Capacity ◽

Common Structure ◽

Wide Range ◽

Working Capability ◽

Main Factors ◽

And Control

The study included children referred by their state of health to the main medical group (n=91). The average age of boys amounted to 9.6±0.05 years, and of girls - 9.5±0.05 years. The set of methods suitable for the study of school-aged children’s physical working capability at the wide range of accessible tensions was studied. The arrangement of the study met demands of Helsinki declaration. During the study 5 main factors determining physical working capacity structure in 9-10 aged children under the vast range of accessible tensions were found out. All the children were certainly health, went in for physical exercises according to commonly accepted program and did not attend sport sections. In the work there was used the complex of methods suitable for the study of the physical performance of schoolchildren in the large range of available loads. During the study there were selected 5 main factors determining the structure of the physical performance of children aged of 9-1-0 years. It is shown that boys’ and girls’ against background of the preservation of the common structure of the performance contributions of considered factors to the summarized dispersion of the sample, and physiological indices included in to the pattern of specific factors and their weight coefficients are distributed in various ways. Boys aged of 9-10 years were established to exceed girls by physical working capacity in all ranges of available loads. Meanwhile the greatest number of significant differences was identified concerning the variables characterizing working capacity in the moderate and high power relating with mainly aerobic and mixed aerobic-anaerobic power supply of muscular activity. Indices of aerobic capacity are characterized with the most differential “sensibility” in comparison with other energy criteria of the working capacity. The results of the study can be used in the solution of practical tasks according to hygienic rating and control of the value of physical loads of different relative power during the process of physical education of children aged of 9-10 years.

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Dielectrical properties of composites LDPE+CB

Hemijska industrija ◽

10.2298/hemind091221035s ◽

2010 ◽

Vol 64 (3) ◽

pp. 187-191

Author(s):

Blanka Skipina ◽

Dusko Dudic ◽

Dusan Kostoski ◽

Jablan Dojcilovic

Keyword(s):

Electrical Conductivity ◽

Polymer Composites ◽

Conductive Polymer ◽

Dissipation Factor ◽

Filler Concentration ◽

Electrical Insulator ◽

Conductive Polymer Composites ◽

Wide Range ◽

Filler Particles ◽

Dielectrical Properties

There is currently great interest in the technological properties of conductive polymer composites because their cost-performance balance. They have a wide range of industrial applications -in anti-static materials, self regulating heaters, current overload and overheating protection devices, and materials for electromagnetic radiation shielding. Measurements of the electrical properties of polymer composites are one of the most convenient and sensitive methods for studying polymer structure. A polymer composite differs substantially from a free polymer in a wide range of properties. The presence of filler affects both the electrical, as well as mechanical properties. One of the most important characteristics of conductive polymer composites is that their electrical conductivity increases nonlinearly with the increase of the concentration of filler particles. When the concentration of filler particles reaches a certain critical value, a drastic transition from an electrical insulator to a conductor is exhibited. This conductivity behavior resulting in a sudden insulator-conductor transition is ascribed to a percolation process, and the critical filler concentration at which the conductivity jump occurs is called ?percolation threshold?. In the past few years, a lot of studies have been carried out to analyze the percolation phenomenon and mechanisms of the conductive behavior in conductive polymer composites. It has been established that the electrical conductivity of conductive polymer composites uncommonly depends on the temperature. Some of such composites show a sharp increase and/or decrease in electrical conductivity at specific temperatures. The conductive temperature coefficient (CTC) of conductive polymer composites has been widely investigated. In these work we investigated how concentration of the CB affects the dielectrical properties of the composite LDPE+CB. The ac electrical conductivity, ?ac, for such composites was measured. The temperature and frequency dependence of the dissipation factor were analyzed. It was found that the ac conductivity and dissipation factor were highly affected by the concentration of the filler.

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