Endurance Time Prediction using Electromyography

2014 ◽  
pp. 219-233 ◽  
Author(s):  
Sébastien Boyas ◽  
Arnaud Guével
Keyword(s):  
Muscle Contraction ◽  
Endurance Time ◽  
Time Prediction ◽  
Emg Signal ◽  
Significant Relationships

The purpose of endurance time (Tlim) prediction is to determine the exertion time of a fatiguing muscle contraction before it occurs. Tlim prediction would then allow the evaluation of muscle capacities while limiting fatigue and deleterious effects associated with exhaustive exercises. Fatigue is a progressive phenomenon which manifestations can be observed since the beginning of the exercise using electromyography (EMG). Studies have reported significant relationships between Tlim and changes in EMG signal suggesting that Tlim could be predicted from early EMG changes recorded during the first half of the fatiguing contraction. However some methodological factors can influence the reliability of the relationships between Tlim and EMG changes. The aim of this chapter is to present the methodology used to predict Tlim from early changes in EMG signal and the factors that may influence its feasibility and reliability. It will also present the possible uses and benefits of the Tlim prediction.

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.

scholarly journals Test-retest reliability of electromyographic signal parameters used to evaluate neuromuscular fatigue in quadriceps femoris muscle

Kinesiology ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Cristiano Rocha da Silva ◽  
Danilo de Oliveira Silva ◽  
Ronaldo Valdir Briani ◽  
Marcella Ferraz Pazzinatto ◽  
Deisi Ferrari ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Neuromuscular Fatigue ◽  
Median Frequency ◽  
Endurance Time ◽  
Retest Reliability ◽  
Emg Signal ◽  
Electromyographic Signal ◽  
Test Retest Reliability ◽  
Voluntary Contractions

The purpose of this study was to analyze the test-retest reliability of the median frequency (MDF) and root mean square (RMS) used to determine the onset of neuromuscular fatigue (NF) during sustained fatiguing contractions of the quadriceps. Eighteen healthy men were tested on two days, and electromyographic (EMG) signals were recorded from the vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL) during sustained isometric contractions at 20 and 70% of maximum voluntary contractions (MVC) held until exhaustion. The reliability of endurance time was excellent at 20% MVC and poor at 70% MVC. EMG variables were evaluated: (1) at the beginning of the test; (2) at NF; and (3) at the end of the test. The NF time values presented poor reliability. The MDF has shown, in general, poor reliability at 20 and 70% MVC, whereas the RMS reliability presented better results for both loads, especially for RF, followed by the VM and VL muscles. The MDF and RMS values extracted from NF showed poor reliability at 20 and 70% MVC, which suggests caution in using these variables extracted from the EMG signal to determine the onset of NF.

Electromyographic Evaluation of Abdominal-Muscle Function With and Without Concomitant Pelvic-Floor-Muscle Contraction

2013 ◽  
Vol 22 (2) ◽  
pp. 108-114 ◽  
Author(s):  
Nahid Tahan ◽  
Amir Massoud Arab ◽  
Bita Vaseghi ◽  
Khosro Khademi
Keyword(s):  
Pelvic Floor ◽  
Muscle Contraction ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Pelvic Floor Muscle ◽  
Abdominal Muscle ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Repeated Measures Design ◽  
Emg Signal

Context:Coactivation of abdominal and pelvic-floor muscles (PFM) is an issue considered by researchers recently. Electromyography (EMG) studies have shown that the abdominal-muscle activity is a normal response to PFM activity, and increase in EMG activity of the PFM concomitant with abdominal-muscle contraction was also reported.Objective:The purpose of this study was to compare the changes in EMG activity of the deep abdominal muscles during abdominal-muscle contraction (abdominal hollowing and bracing) with and without concomitant PFM contraction in healthy and low-back-pain (LBP) subjects.Design:A 2 × 2 repeated-measures design.Setting:Laboratory.Participants:30 subjects (15 with LBP, 15 without LBP).Main Outcome Measures:Peak rectified EMG of abdominal muscles.Results:No difference in EMG of abdominal muscles with and without concomitant PFM contraction in abdominal hollowing (P = .84) and abdominal bracing (P = .53). No difference in EMG signal of abdominal muscles with and without PFM contraction between LBP and healthy subjects in both abdominal hollowing (P = .88) and abdominal bracing (P = .98) maneuvers.Conclusion:Adding PFM contraction had no significant effect on abdominal-muscle contraction in subjects with and without LBP.

EMG for Subtle, Intimate Interfaces

2008 ◽  
pp. 524-542
Author(s):  
Enrico Costanza ◽  
Samuel A. Inverso ◽  
Rebecca Allen ◽  
Pattie Maes
Keyword(s):  
Muscle Contraction ◽  
Muscle Activity ◽  
Experimental Results ◽  
Input Device ◽  
Multimodal Interface ◽  
Volitional Control ◽  
Upper Arm ◽  
Input Modality ◽  
Emg Signal ◽  
Mobile Interfaces

Mobile interfaces should be designed to enable subtle, discreet, and unobtrusive interaction. Biosignals and, in particular, the electromyographic (EMG) signal, can provide a subtle input modality for mobile interfaces. The EMG signal is generated by a muscle contraction and can be used for volitional control; its greatest potential for mobile interfaces is its ability to sense muscle activity not related to movement. An EMG-based wearable input device, the Intimate Communication Armband, is presented in this chapter to demonstrate this subtle interaction concept. The device detects subtle, motionless gestures from the upper arm. Experimental results show that the gestures are reliably recognized without user or machine training, that the system can be used effectively to control a multimodal interface, and that it is very difficult for observers to guess when a trained user is performing subtle gestures, confirming the subtlety of the proposed interaction.

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