Differences in muscular activation and fatigue for intermittent and constant load

2005 ◽  
Vol 5 (1) ◽  
pp. 43-56
Author(s):  
Danuta Roman-Liu ◽  
Krzysztof Kȩdzior
Keyword(s):  
External Force ◽  
Upper Limb ◽  
Muscle Activation ◽  
Regression Line ◽  
Constant Load ◽  
Median Frequency ◽  
Experimental Conditions ◽  
Emg Signal ◽  
Limb Posture ◽  
Muscular Activation

The aim of this study was to compare the influence of constant or intermittent load on muscle activation and fatigue. The analysis and assessment of muscular activation and fatigue was based on surface EMG measurements from eight muscles (seven muscles of the right upper limb and trapezius muscle). Two EMG signal parameters were analyzed for each of the experimental conditions distinguished by the value of the external force and the character of the load – constant or intermittent. The amplitude related to its maximum (AMP) and the slope of the regression line between time and median frequency (SMF) were the EMG parameters that were analyzed. The results showed that constant load caused higher muscular fatigue than intermittent load despite the lower value of the external force and lower muscle activation. Results suggest that additional external force might influence muscle activation and fatigue more than upper limb posture. The results of the study support the thesis that all biomechanical factors which influence upper limb load and fatigue (upper limb posture, external force and time sequences) should be considered when work stands and work processes are designed. They also indicate that constant load should be especially avoided.

scholarly journals Focus of attention and online demonstration effects on temporal error and muscle activation

2020 ◽  
Vol 22 ◽  
Author(s):  
Tércio Apolinário-Souza ◽  
Herbert Ugrinowitsch ◽  
Carlos Eduardo Campos ◽  
Lucas Túlio de Lacerda ◽  
Frank Douglas Tourino ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Muscle Activation ◽  
Focus Of Attention ◽  
Emg Activity ◽  
Muscle Action ◽  
Experimental Conditions ◽  
Leg Extension ◽  
External Focus ◽  
Internal Focus ◽  
Muscular Activation

Abstract The purpose of the present study was to examine whether there would be performance differences between external and internal focus of attention conditions and an online demonstration condition, and if these differences would be observed at a neuromuscular level through EMG analysis, in addition to traditional outcome measures. We hypothesized that under the demonstration condition participants would perform better than under external and internal focus conditions. We also hypothesized that demonstration condition would show smaller EMG activity than external and internal focus conditions. Furthermore, we hope to replicate the benefits of external focus in relation to internal focus, both in outcome and product measures. Six male participants performed a bilateral leg extension under internal focus of attention, external focus of attention and online demonstration conditions. Muscular contractions goal times were set for concentric muscle action (4 seconds) and eccentric muscle action (2 seconds). An electrogoniometer was used to record muscular activation (production measures), and temporal error was used to observe performance (outcome measures). Results showed that online demonstration condition obtained better performance than external focus condition and a reduced muscular activation. However, differences between internal focus and the other experimental conditions were not found. These findings advance in the understanding mechanisms underpining the focus of attention, such as proposed by Constrained Action Hypothesis.

Comparison of three computer office workstations offering forearm support: impact on upper limb posture and muscle activation

Ergonomics ◽  
2006 ◽  
Vol 49 (2) ◽  
pp. 139-160 ◽  
Author(s):  
Alain Delisle ◽  
Christian Larivière ◽  
André Plamondon ◽  
Daniel Imbeau
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Limb Posture

scholarly journals Effect of Low-Temperature Annealing on Creep Properties of AlSi10Mg Alloy Produced by Additive Manufacturing: Experiments and Modeling

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 179
Author(s):  
Chiara Paoletti ◽  
Emanuela Cerri ◽  
Emanuele Ghio ◽  
Eleonora Santecchia ◽  
Marcello Cabibbo ◽  
...  
Keyword(s):  
Creep Rate ◽  
Applied Stress ◽  
Minimum Creep Rate ◽  
Annealing Treatment ◽  
Constant Load ◽  
Experimental Conditions ◽  
Creep Properties ◽  
Low Temperature Annealing ◽  
Physically Based ◽  
Excellent Description

The effects of postprocessing annealing at 225 °C for 2 h on the creep properties of AlSi10Mg alloy were investigated through constant load experiments carried out at 150 °C, 175 °C and 225 °C. In the range of the experimental conditions here considered, the annealing treatment resulted in an increase in minimum creep rate for a given stress. The reduction in creep strength was higher at the lowest temperature, while the effect progressively vanished as temperature increased and/or applied stress decreased. The minimum creep rate dependence on applied stress was modeled using a physically-based model which took into account the ripening of Si particles at high temperature and which had been previously applied to the as-deposited alloy. The model was successfully validated, since it gave an excellent description of the experimental data.

INTELLIGENT UPPER-LIMB PROSTHETIC CONTROL (iULP) WITH NOVEL FEATURE EXTRACTION METHOD FOR PATTERN RECOGNITION USING EMG

2021 ◽  
pp. 2150043
Author(s):  
SIDHARTH PANCHOLI ◽  
AMIT M. JOSHI
Keyword(s):  
Pattern Recognition ◽  
Upper Limb ◽  
Classification Accuracy ◽  
Time Derivative ◽  
Machine Learning Algorithms ◽  
Prosthetic Control ◽  
Myoelectric Prosthesis ◽  
Feature Extraction Method ◽  
Similar Work ◽  
Emg Signal

EMG signal-based pattern recognition (EMG-PR) techniques have gained lots of focus to develop myoelectric prosthesis. The performance of the prosthesis control-based applications mainly depends on extraction of eminent features with minimum neural information loss. The machine learning algorithms have a significant role to play for the development of Intelligent upper-limb prosthetic control (iULP) using EMG signal. This paper proposes a new technique of extracting the features known as advanced time derivative moments (ATDM) for effective pattern recognition of amputees. Four heterogeneous datasets have been used for testing and validation of the proposed technique. Out of the four datasets, three datasets have been taken from the standard NinaPro database and the fourth dataset comprises data collected from three amputees. The efficiency of ATDM features is examined with the help of Davies–Bouldin (DB) index for separability, classification accuracy and computational complexity. Further, it has been compared with similar work and the results reveal that ATDM features have excellent classification accuracy of 98.32% with relatively lower time complexity. The lower values of DB criteria prove the good separation of features belonging to various classes. The results are carried out on 2.6[Formula: see text]GHz Intel core i7 processor with MATLAB 2015a platform.

scholarly journals Muscle Activation during Exergame Playing

2016 ◽  
pp. 312-341 ◽  
Author(s):  
Pooya Soltani ◽  
João Paulo Vilas-Boas
Keyword(s):  
Upper Limb ◽  
Healthy Subjects ◽  
Muscle Activation ◽  
Low Cost ◽  
Coding System ◽  
User Research ◽  
Preliminary Results ◽  
Upper Trapezius ◽  
Game Developers ◽  
Muscular Coordination

Exergames may provide low-cost solutions for playing, training and rehabilitation. Exergame user research, studies the interaction between an exergame and users, in order to provide feedback for game developers and safe and meaningful game play. Detailed evaluations and a coding system based on muscle activation levels are necessary to characterize. This is important when it comes to use exergames in purposes other than fun. The purpose of this chapter was to characterize the muscle activation during a swimming exergame and to compare the level of activation during different conditions. Healthy subjects played bouts of exergame using Xbox360 and Kinect. Muscle activation was monitored for desired muscles on dominant upper limb using wireless electromyography system. An investigation of muscular coordination was also conducted to provide activation sequences of studied muscles. Preliminary results showed that upper trapezius was the most active muscle in all techniques. Results can provide insights for practitioners to have a baseline on application of exergames in their routines.

scholarly journals Comparison of tibialis anterior and gastrocnemius muscles activation on balance training devices and hoverboard

2017 ◽  
Vol 13 (4-2) ◽  
pp. 495-500 ◽  
Author(s):  
Khairiyah Abdul Rahman ◽  
Aizreena Azaman ◽  
Hadafi Fitri Mohd Latip ◽  
Mohd Azuwan Mat Dzahir ◽  
Malarvili Balakrishnan
Keyword(s):  
Frequency Domain ◽  
Time Domain ◽  
Tibialis Anterior ◽  
Gastrocnemius Muscle ◽  
Balance Training ◽  
Domain Analysis ◽  
Median Frequency ◽  
Training Device ◽  
Emg Signal ◽  
Significant Difference

Balance training devices such as wobble board, basu ball and balance cushion are the tool use in balance training exercise programme in order to improve muscle strength and restore posture balance due degeneration of body function or injury. Recently, self-balancing scooter such as Segway and hover board showed a positive effects on rehabilitation. However, it is less known how these devices affect muscle physiological properties. This study aims to to measure ankle muscles activation on  difference balance training devices and hover board. Besides, a comparison between these device will be done in order to identify if hover board has a promising feature to be an alternative balance training device. In this research, surface EMG (sEMG) was used to record tibialis anterior and gastrocnemius muscle activities. Seventeen healthy subjects were required to stand on three different types of balance training device such as wobble board, balance cushion, bosu ball and a hover board. They were asked to maintain their standing position on each devices for two minutes. Both time domain and frequency domain analysis were used to identify the features of the EMG signal. Time domain analysis measurement involved average rectified value (ARV) and root mean square (RMS), meanwhile for frequency domain, median frequency (MDF) of the signal were measured. The results shows that, the RMS is differed significantly between the balance training devices (p<0.05) for tibialis anterior muscle but not gastrocnemius muscle. Meanwhile, no significant difference between the devices in the ARV and the MDF value (p>0.05). Besides, less stable devices increased muscle activity were observed. There is not much difference between hover board and the other devices in term of physiological effects of both tibialis anterior and gastrochemious muscle. It is also suggested that hover board offers a promising feature to be an alternative device for balance training device.

The Comparison and Analysis of SEMG in Upper Limb Movement between Hemiplegic Patients and Healthy People

2015 ◽  
Vol 719-720 ◽  
pp. 969-972
Author(s):  
Teng Yu Zhang ◽  
Chun Jing Tao
Keyword(s):  
Muscle Contraction ◽  
Frequency Domain ◽  
Upper Limb ◽  
Healthy People ◽  
Limb Movements ◽  
Surface Electromyogram ◽  
Emg Signal ◽  
Upper Limb Movements ◽  
Comparison And Analysis ◽  
Common Action

In this paper, the surface electromyogram (EMG) signal of the hemiplegic patients and healthy people were collected when completing upper limb movements, then the general EMG characteristic rules of healthy people in common action were analyzed, and the EMG characteristics of hemiplegic patients in time and frequency domain were extracted. By comparing and analyzing the EMG characteristics between the hemiplegic patients and healthy people, the results showed that the order and magnitude of muscle contraction of hemiplegic patients were not comply with the general laws of healthy people, which resulted in disorganized movement.

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