scholarly journals Enhancement of muscle’s activity by woven compression bandage

2021 ◽  
Vol 72 (04) ◽  
pp. 408-417
Author(s):  
ABDELHAMID R.R. ABOALASAAD ◽  
BRIGITA K. SIRKOVÁ ◽  
GOZDE GONCU-BERK
Keyword(s):  
Electrical Activity ◽  
Root Mean Square ◽  
Main Tool ◽  
Medial Gastrocnemius ◽  
Median Frequency ◽  
Compression Bandage ◽  
Mean Square ◽  
Electrical Voltage ◽  
Flexion Extension ◽  
Calf Muscles

Electromyography (EMG) test, the recording of electrical activity in muscle, is a main tool usually used to evaluate themuscle’s activation. This study aims to discuss and analyse the effect of woven compression bandage (WCB) onmuscles’ activation. Flexor Carpi (FC), Soleus (SO), and Medial Gastrocnemius (MG) muscles were selected torepresent the wrist, ankle, and mid-calf muscles respectively, which were then evaluated by EMG electrical voltage testwith and without wearing WCB. The standardized activities used to test the FC muscle were flexion-extension andsqueezing a soft roll. While the protocol activities for MG and SO muscles were flexion-extension and walking actions.Wearing WCB significantly decreased the muscle’s activation and was associated with higher median frequency for bothSO and MG muscles during the tested activities. The EMG signals were analysed and filtered using MegaWin andMATLAB software. Root mean square (RMS) values confirmed that wearing WCB could improve the performance of FC,SO, and MG muscles and might reduce the muscle’s fatigue during the selected activities.

scholarly journals An EMG Patch for the Real-Time Monitoring of Muscle-Fatigue Conditions During Exercise

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3108 ◽  
Author(s):  
Shing-Hong Liu ◽  
Chuan-Bi Lin ◽  
Ying Chen ◽  
Wenxi Chen ◽  
Tai-Shen Huang ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Real Time ◽  
Root Mean Square ◽  
The Body ◽  
Median Frequency ◽  
Mean Square ◽  
Sport Injuries ◽  
Physiological Measurement ◽  
The Real ◽  
Emg Signal

In recent years, wearable monitoring devices have been very popular in the health care field and are being used to avoid sport injuries during exercise. They are usually worn on the wrist, the same as sport watches, or on the chest, like an electrocardiogram patch. Common functions of these wearable devices are that they use real time to display the state of health of the body, and they are all small sized. The electromyogram (EMG) signal is usually used to show muscle activity. Thus, the EMG signal could be used to determine the muscle-fatigue conditions. In this study, the goal is to develop an EMG patch which could be worn on the lower leg, the gastrocnemius muscle, to detect real-time muscle fatigue while exercising. A micro controller unit (MCU) in the EMG patch is part of an ARM Cortex-M4 processor, which is used to measure the median frequency (MF) of an EMG signal in real time. When the muscle starts showing tiredness, the median frequency will shift to a low frequency. In order to delete the noise of the isotonic EMG signal, the EMG patch has to run the empirical mode decomposition algorithm. A two-electrode circuit was designed to measure the EMG signal. The maximum power consumption of the EMG patch was about 39.5 mAh. In order to verify that the real-time MF values measured by the EMG patch were close to the off-line MF values measured by the computer system, we used the root-mean-square value to estimate the difference in the real-time MF values and the off-line MF values. There were 20 participants that rode an exercise bicycle at different speeds. Their EMG signals were recorded with an EMG patch and a physiological measurement system at the same time. Every participant rode the exercise bicycle twice. The averaged root-mean-square values were 2.86 ± 0.86 Hz and 2.56 ± 0.47 Hz for the first and second time, respectively. Moreover, we also developed an application program implemented on a smart phone to display the participants’ muscle-fatigue conditions and information while exercising. Therefore, the EMG patch designed in this study could monitor the muscle-fatigue conditions to avoid sport injuries while exercising.

scholarly journals Effect of synchronization of firings of different motor unit types on the force variability in a model of the rat medial gastrocnemius muscle

2021 ◽  
Vol 17 (4) ◽  
pp. e1008282
Author(s):  
Rositsa Raikova ◽  
Vessela Krasteva ◽  
Piotr Krutki ◽  
Hanna Drzymała-Celichowska ◽  
Katarzyna Kryściak ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Gastrocnemius Muscle ◽  
Muscle Force ◽  
Time Window ◽  
Medial Gastrocnemius ◽  
Force Variability ◽  
Mean Square ◽  
Synchronization Index ◽  
The Mean ◽  
Medial Gastrocnemius Muscle

The synchronized firings of active motor units (MUs) increase the oscillations of muscle force, observed as physiological tremors. This study aimed to investigate the effects of synchronizing the firings within three types of MUs (slow—S, fast resistant to fatigue–FR, and fast fatigable–FF) on the muscle force production using a mathematical model of the rat medial gastrocnemius muscle. The model was designed based on the actual proportion and physiological properties of MUs and motoneurons innervating the muscle. The isometric muscle and MU forces were simulated by a model predicting non-synchronized firing of a pool of 57 MUs (including 8 S, 23 FR, and 26 FF) to ascertain a maximum excitatory signal when all MUs were recruited into the contraction. The mean firing frequency of each MU depended upon the twitch contraction time, whereas the recruitment order was determined according to increasing forces (the size principle). The synchronization of firings of individual MUs was simulated using four different modes and inducing the synchronization of firings within three time windows (± 2, ± 4, and ± 6 ms) for four different combinations of MUs. The synchronization was estimated using two parameters, the correlation coefficient and the cross-interval synchronization index. The four scenarios of synchronization increased the values of the root-mean-square, range, and maximum force in correlation with the increase of the time window. Greater synchronization index values resulted in higher root-mean-square, range, and maximum of force outcomes for all MU types as well as for the whole muscle output; however, the mean spectral frequency of the forces decreased, whereas the mean force remained nearly unchanged. The range of variability and the root-mean-square of forces were higher for fast MUs than for slow MUs; meanwhile, the relative values of these parameters were highest for slow MUs, indicating their important contribution to muscle tremor, especially during weak contractions.

scholarly journals Muscular Behavior during Inspiratory Training in Patients with a Complete Cervical Spinal Cord Injury: Pilot Study

2016 ◽  
Vol 85 (3) ◽  
Author(s):  
Tomás Santibáñez Arellano
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Root Mean Square ◽  
Cervical Spinal Cord ◽  
Training Session ◽  
Cervical Spinal Cord Injury ◽  
Median Frequency ◽  
Mean Square ◽  
Muscle Training ◽  
Cord Injury

Introduction: There is a huge variety of inspiratory muscle training protocols in patients with complete cervical spinal cord injury. None of them provide information about muscle behavior and its relationship with effort and fatigue sensation perceived by the subject.Objective: Analyze the relationship between the behavior of the Median Frequency (MF) and the Root Mean Square (RMS) of diaphragm (DPH) and sternocleidomastoid (ECOM) muscles and Subjective Fatigue Sensation (SFS) during an inspiratory muscle training session using a threshold valve in patients with CCSCI.Methods: Electromyographic activity of the DPH and ECOM during a fifteen minutes training session using a threshold valve with a Maximum Inspiratory Pressure (MIP) of 30% was recorded. Median Frequency average and the Root Mean Square of DPH and ECOM was calculated. SFS was recorded every minute. The correlation between variables was determined by Spearman rho.Results: The correlation between SFS and MF of the DPH was 0.22. The correlation between SFS and MF of the ECOM was 0.36. The correlation between SF and RMS_INDEX was -0.09.Conclusion: There is no correlation between the variables studied. The RMS_INDEX is presented as a useful tool to describe the muscle behavior during training with threshold valve.Results: The correlation between SFS and MF of the DPH was 0.22. The correlation between SFS and MF of the ECOM was 0.36. The correlation between SF and RMS_INDEX was -0.09.Results: The correlation between SFS and MF of the DPH was 0.22. The correlation between SFS and MF of the ECOM was 0.36. The correlation between SF and RMS_INDEX was -0.09.Comportamento muscular durante treino inspiratório em pacientes com lesão medular cervical completa: estudo pilotoIntrodução: Existe uma grande variedade de protocolos de treinos inspiratórios em pacientes com lesão medular cervical completa. Nenhum deles passa informação a respeito do comportamento muscular nem sua relação com a sensação de esforço e fadiga percebida pelo sujeito.Objetivo: Analisar a relação entre o comportamento da FM e raiz media quadrática (RMS) de diafragma (DPH) e esternocleidomastóideo (ECOM) e a SSF durante uma sessão de treino de musculatura inspiratória com válvula umbral em pacientes com LMCC.Métodos: Foi registrada a atividade eletromiográfica do diafragma e o esternocleidomastoideo durante quinze minutos de treino com válvula umbral a 30% de PIM. Foi calculada a frequência média e a raiz quadrada média do DPH e ECOM. Foi registrada a SSF a cada minuto. Foi determinada a correlação entre as variáveis mediante rho de Spearman.Resultados: A correlação entre SSF e FM de DPH foi 0.22. A correlação entre SSF e FM de ECOM foi 0.36. A correlação entre SSF e RMS_INDEX foi -0.09.Conclusão: Não existe correlação entre as variáveis estudadas. O RMS_INDEX é apresentado como uma ferramenta útil para descrever o comportamento muscular durante um treino com a válvula umbral.

scholarly journals Computation and Evaluation of Features of Surface Electromyogram to Identify the Force of Muscle Contraction and Muscle Fatigue

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sridhar P. Arjunan ◽  
Dinesh K. Kumar ◽  
Ganesh Naik
Keyword(s):  
Muscle Contraction ◽  
Muscle Fatigue ◽  
Root Mean Square ◽  
Linear Regression Analysis ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Median Frequency ◽  
Mean Square ◽  
Surface Electromyogram ◽  
The Relationship

The relationship between force of muscle contraction and muscle fatigue with six different features of surface electromyogram (sEMG) was determined by conducting experiments on thirty-five volunteers. The participants performed isometric contractions at 50%, 75%, and 100% of their maximum voluntary contraction (MVC). Six features were considered in this study:normalised spectral index (NSM5), median frequency, root mean square, waveform length, normalised root mean square (NRMS), and increase in synchronization (IIS) index. Analysis of variance (ANOVA) and linear regression analysis were performed to determine the significance of the feature with respect to the three factors: muscle force, muscle fatigue, and subject. The results show that IIS index of sEMG had the highest correlation with muscle fatigue and the relationship was statistically significant (P<0.01), while NSM5 associated best with level of muscle contraction (%MVC) (P<0.01). Both of these features were not affected by the intersubject variations (P>0.05).

scholarly journals Effect of synchronization of firings of different motor unit types on the force variability in a model of the rat medial gastrocnemius muscle

2020 ◽  
Author(s):  
Rositsa Raikova ◽  
Vessela Krasteva ◽  
Piotr Krutki ◽  
Hanna Drzymała-Celichowska ◽  
Katarzyna Kryściak ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Gastrocnemius Muscle ◽  
Motor Units ◽  
Medial Gastrocnemius ◽  
Force Variability ◽  
Mean Square ◽  
Synchronization Index ◽  
The Mean ◽  
Whole Muscle ◽  
Medial Gastrocnemius Muscle

AbstractOscillations of muscle force, observed as physiological tremors, rely upon the synchronized firings of active motor units (MUs). This study aimed to investigate the effects of synchronizing the firings of three types of MUs on force development using a mathematical model of the rat medial gastrocnemius muscle. The model was designed based on the actual proportion and physiological properties of MUs and motoneurons innervating the muscle. The isometric muscle and MU forces were simulated by a model predicting non-synchronized firing of a pool of 57 MUs (including eight slow, 23 fast resistant to fatigue, and 26 fast fatigable) to ascertain a maximum excitatory signal when all MUs were recruited into the contraction. The mean firing frequency of each MU depended upon the twitch contraction time, whereas the recruitment order was determined according to increasing forces (the size principle). The synchronization of firings of individual MUs was simulated using four different modes and inducing the synchronization of firings within three time windows (± 2, ± 4, and ± 6 ms) for four different combinations of MUs. The synchronization was estimated using two parameters, the correlation coefficient and the cross-interval synchronization index. The four scenarios of synchronization increased the values of the root-mean-square, range, and maximum force in correlation with the increase of the time window. Greater synchronization index values resulted in higher root-mean-square, range, and maximum of force outcomes for all MU types as well as for the whole muscle output; however, the mean spectral frequency of the forces decreased, whereas the mean force remained nearly unchanged. The range of variability and the root-mean-square of forces were higher for fast MUs than for slow MUs; meanwhile, the relative values of these parameters were highest for slow MUs, indicating their important contribution to muscle tremor, especially during weak contractions.Author summaryThe synchronization of firings of motor units (MUs), the smallest functional elements of skeletal muscle increases fluctuations in muscle force, known as physiological tremor, which can disturb high-precision movements. In this study, we adopted a recently proposed muscle model consisting of MUs of three different types (fast fatigable, fast resistant to fatigue, and slow) to study four different scenarios of MU synchronization during a steady level of excitatory input to motoneurons. The discharge patterns were synchronized between pairs of MUs by shifting in time individual pulses, which occurred within a short time interval, and a degree of synchronization was then estimated. The increased synchronization index resulted in increased force variability for all MU types as well as for the whole muscle output; however, the mean force levels remained nearly unchanged, whereas the frequencies of the force oscillations were decreased. The absolute range of force variability was higher for fast than for slow MUs, indicating their dominant influence on muscle tremor at strong contractions, but the highest relative increase in force variability was observed for synchronized slow MUs, indicating their significant contribution to tremor during weak contractions, in which only slow MUs are active.

scholarly journals Quantifying in vivo scaphoid, lunate, and capitate kinematics using four-dimensional computed tomography

2020 ◽  
Vol 50 (2) ◽  
pp. 351-359
Author(s):  
Michelle Brinkhorst ◽  
Mahyar Foumani ◽  
Joost van Rosmalen ◽  
Ruud Selles ◽  
Steven Hovius ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Quantitative Description ◽  
Mean Square ◽  
Multiple Correlation ◽  
Motion Patterns ◽  
In Vivo Kinematics ◽  
Flexion Extension ◽  
Carpal Kinematics ◽  
Quantifying In

Abstract Objective We aimed to establish a quantitative description of motion patterns and establish test-retest reliability of the four-dimensional CT when quantifying in vivo kinematics of the scaphoid, lunate, and capitate. Materials and methods We assessed in vivo kinematics of both wrists of 20 healthy volunteers (11 men and 9 women) between the ages of 20 and 40 years. All volunteers performed active flexion-extension and radial-ulnar deviation with both wrists. To test for reliability, one motion cycle was rescanned for both wrists approximately 15 min after the first scan. The coefficient of multiple correlation was used to analyze reliability. When two motion patterns are similar, the coefficient of multiple correlation tends towards 1, whereas in dissimilar motion patterns, it tends towards 0. The root mean square deviation was used to analyze the total motion patterns variability between the two scans. Results Overall, mean or median coefficient of multiple correlations were higher than 0.86. The root mean square deviations were low and ranged from 1.17° to 4.29°. Conclusion This innovative non-invasive imaging technique can reliably describe in vivo carpal kinematics of uninjured wrists in healthy individuals. It provides us with a better understanding and reference values of carpal kinematics of the scaphoid, lunate, and capitate.

Myoelectric manifestations of fatigue in voluntary and electrically elicited contractions

1990 ◽  
Vol 69 (5) ◽  
pp. 1810-1820 ◽  
Author(s):  
R. Merletti ◽  
M. Knaflitz ◽  
C. J. De Luca
Keyword(s):  
Muscle Fatigue ◽  
Root Mean Square ◽  
Conduction Velocity ◽  
Time Course ◽  
Tibialis Anterior Muscle ◽  
Median Frequency ◽  
Mean Square ◽  
Myoelectric Signal ◽  
Physiological Factor ◽  
Voluntary Contractions

The time course of muscle fiber conduction velocity and surface myoelectric signal spectral (mean and median frequency of the power spectrum) and amplitude (average rectified and root-mean-square value) parameters was studied in 20 experiments on the tibialis anterior muscle of 10 healthy human subjects during sustained isometric voluntary or electrically elicited contractions. Voluntary contractions at 20% maximal voluntary contraction (MVC) and at 80% MVC with duration of 20 s were performed at the beginning of each experiment. Tetanic electrical stimulation was then applied to the main muscle motor point for 20 s with surface electrodes at five stimulation frequencies (20, 25, 30, 35, and 40 Hz). All subjects showed myoelectric manifestations of muscle fatigue consisting of negative trends of spectral variables and conduction velocity and positive trends of amplitude variables. The main findings of this work are 1) myoelectric signal variables obtained from electrically elicited contractions show fluctuations smaller than those observed in voluntary contractions, 2) spectral variables are more sensitive to fatigue than conduction velocity and the average rectified value is more sensitive to fatigue than the root-mean-square value, 3) conduction velocity is not the only physiological factor affecting spectral variables, and 4) contractions elicited at supramaximal stimulation and frequencies greater than 30 Hz demonstrate myoelectric manifestations of muscle fatigue greater than those observed at 80% MVC sustained for the same time.

Neuromuscular fatigue development during maximal concentric and isometric knee extensions

2006 ◽  
Vol 100 (3) ◽  
pp. 780-785 ◽  
Author(s):  
Nicolas Babault ◽  
Kevin Desbrosses ◽  
Marie-Sophie Fabre ◽  
Anne Michaut ◽  
Michel Pousson
Keyword(s):  
Root Mean Square ◽  
Vastus Lateralis ◽  
Neuromuscular Fatigue ◽  
Peripheral Fatigue ◽  
Vastus Lateralis Muscle ◽  
Electromyographic Activity ◽  
Median Frequency ◽  
Mean Square ◽  
Fatigue Development ◽  
Frequency Changes

This study aimed to investigate mechanisms of neuromuscular fatigue during maximal concentric and isometric leg extensions inducing similar torque decrements. Nine physically active men performed two separate fatiguing sessions maintained until similar torque decreases were obtained. The first session, only conducted under isokinetic concentric conditions (CON), consisted of three series of 30 maximal voluntary concentric knee extensions (60°/s). The second session, exclusively isometric (ISO), mimicked the torque decreases registered during the CON session while performing three long-lasting ISO contractions. Maximal voluntary torque, activation level (twitch interpolation technique), electromyographic activity (root mean square and median frequency) of the vastus lateralis muscle, and electrically evoked doublet-twitch mechanical properties were measured before and at the end of each of the three series. After the three series, similar torque decrements were obtained for both fatiguing procedures. The total fatiguing contraction durations were not different among procedures. With equivalent voluntary torque decrements, the doublet-twitch amplitude reduction was significantly greater ( P < 0.01) during the two first series of the CON procedure compared with ISO. No difference was observed for the third series. Although no difference was recorded with fatigue for median frequency changes between CON and ISO, activation levels and root mean square values demonstrated greater reductions ( P < 0.05) for all three series during the ISO procedure compared with CON. Performing CON or ISO fatiguing exercises demonstrated different fatigue origins. With CON exercises, peripheral fatigue developed first, followed by central fatigue, whereas with ISO exercises the fatigue pattern was inverted.

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