Evaluation of total muscular activity by quantification of electromyograms through a summing amplifier

1970 ◽  
Vol 8 (4) ◽  
pp. 343-356 ◽  
Author(s):  
R. H. Harding ◽  
R. N. Sen
1994 ◽  
Vol 33 (01) ◽  
pp. 157-160 ◽  
Author(s):  
S. Kruse-Andersen ◽  
J. Kolberg ◽  
E. Jakobsen

Abstract:Continuous recording of intraluminal pressures for extended periods of time is currently regarded as a valuable method for detection of esophageal motor abnormalities. A subsequent automatic analysis of the resulting motility data relies on strict mathematical criteria for recognition of pressure events. Due to great variation in events, this method often fails to detect biologically relevant pressure variations. We have tried to develop a new concept for recognition of pressure events based on a neural network. Pressures were recorded for over 23 hours in 29 normal volunteers by means of a portable data recording system. A number of pressure events and non-events were selected from 9 recordings and used for training the network. The performance of the trained network was then verified on recordings from the remaining 20 volunteers. The accuracy and sensitivity of the two systems were comparable. However, the neural network recognized pressure peaks clearly generated by muscular activity that had escaped detection by the conventional program. In conclusion, we believe that neu-rocomputing has potential advantages for automatic analysis of gastrointestinal motility data.


2020 ◽  
Vol 11 ◽  
Author(s):  
Elena Laura Georgescu Margarint ◽  
Ioana Antoaneta Georgescu ◽  
Carmen Denise Mihaela Zahiu ◽  
Stefan-Alexandru Tirlea ◽  
Alexandru Rǎzvan Şteopoaie ◽  
...  

The execution of voluntary muscular activity is controlled by the primary motor cortex, together with the cerebellum and basal ganglia. The synchronization of neural activity in the intracortical network is crucial for the regulation of movements. In certain motor diseases, such as dystonia, this synchrony can be altered in any node of the cerebello-cortical network. Questions remain about how the cerebellum influences the motor cortex and interhemispheric communication. This research aims to study the interhemispheric cortical communication between the motor cortices during dystonia, a neurological movement syndrome consisting of sustained or repetitive involuntary muscle contractions. We pharmacologically induced lateralized dystonia to adult male albino mice by administering low doses of kainic acid on the left cerebellar hemisphere. Using electrocorticography and electromyography, we investigated the power spectral densities, cortico-muscular, and interhemispheric coherence between the right and left motor cortices, before and during dystonia, for five consecutive days. Mice displayed lateralized abnormal motor signs, a reduced general locomotor activity, and a high score of dystonia. The results showed a progressive interhemispheric coherence decrease in low-frequency bands (delta, theta, beta) during the first 3 days. The cortico-muscular coherence of the affected side had a significant increase in gamma bands on days 3 and 4. In conclusion, lateralized cerebellar dysfunction during dystonia was associated with a loss of connectivity in the motor cortices, suggesting a possible cortical compensation to the initial disturbances induced by cerebellar left hemisphere kainate activation by blocking the propagation of abnormal oscillations to the healthy hemisphere. However, the cerebellum is part of several overly complex circuits, therefore other mechanisms can still be involved in this phenomenon.


2007 ◽  
Vol 15 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Heiner Baur ◽  
Anja Hirschmüller ◽  
Steffen Müller ◽  
Albert Gollhofer ◽  
Frank Mayer
Keyword(s):  

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 560
Author(s):  
Fabiola Spolaor ◽  
Marco Romanato ◽  
Guiotto Annamaria ◽  
Antonella Peppe ◽  
Leila Bakdounes ◽  
...  

The aim of this study was to investigate the effects of Equistasi®, a wearable device, on the relationship between muscular activity and postural control changes in a sample of 25 Parkinson’s disease (PD) subjects. Gait analysis was carried out through a six-cameras stereophotogrammetric system synchronized with two force plates, an eight-channel surface electromyographic system, recording the activity of four muscles bilaterally: Rectus femoris, tibialis anterior (TA), biceps femoris, and gastrocnemius lateralis (GL). The peak of the envelope (PoE) and its occurrence within the gait cycle (position of the peak of the envelope, PPoE) were calculated. Frequency-domain posturographic parameters were extracted while standing still on a force plate in eyes open and closed conditions for 60 s. After the treatment with Equistasi®, the mid-low (0.5–0.75) Hz and mid-high (0.75–1 Hz) components associated with the vestibular and somatosensory systems, PoE and PPoE, displayed a shift toward the values registered on the controls. Furthermore, a correlation was found between changes in proprioception (power spectrum frequencies during the Romberg Test) and the activity of GL, BF (PoE), and TA (PPoE). Results of this study could provide a quantitative estimation of the effects of a neurorehabilitation device on the peripheral and central nervous system in PD.


1985 ◽  
Vol 110 (3_Suppla) ◽  
pp. S11-S18 ◽  
Author(s):  
H. Kopera

Metabolism is the term employed to embrace the various physical and chemical processes occurring within the tissues upon which the growth and heat production of the body depend and from which the energy for muscular activity, for the maintenance of vital activity and for the maintenance of vital functions is derived (Best & Taylor 1950). The destructive processes by which complex substances are converted by living cells into more simple compounds are called catabolism. Anabolism denotes the constructive processes by which simple substances are converted by living cells into more complex compounds, especially into living matter. Catabolism and anabolism are part of all metabolic processes, the carbohydrate, fat and protein metabolism. The term anabolic refers only to substances that exert an anabolic effect on protein metabolism and are unlikely to cause adverse androgenic effects. They shift the equilibrium between protein synthesis and degradation in the body as a whole in the direction of synthesis, either by promoting protein synthesis or reducing its breakdown. The protein anabolic effect of anabolic steroids is not restricted to single organs but is the result of stimulated biosynthesis of cellular protein in the whole organism.


Medicina ◽  
2019 ◽  
Vol 56 (1) ◽  
pp. 8 ◽  
Author(s):  
Vanesa Abuín-Porras ◽  
Mónica de la Cueva-Reguera ◽  
Pedro Benavides-Morales ◽  
Rocío Ávila-Pérez ◽  
Blanca de la Cruz-Torres ◽  
...  

Background and Objectives: Rugby players engage in demanding, high loading muscular activity in the spine. Study of the abdominal wall architecture in female rugby athletes is relevant to the possible muscular asymmetry secondary to sport practice and the relationship between the abdominal wall and the pelvic floor muscles. Activation of the transversus abdominis (TrAb) generates an increase in the bladder neck muscle. Moreover, an increased interrecti distance (IRD) is related to urinary incontinence and has a higher prevalence in athletic women. The aim of the present study was to compare and quantify, with ultrasound imaging (USI), the thickness of the transversus abdominis (TrAb), external oblique (EO), internal oblique (IO), rectus abdominis (RA), and interrecti distance (IRD) in female rugby players versus non-athletic women in order to improve upon existing knowledge about abdominal wall configuration in female athletes. Materials and Methods: A sample of 32 women was recruited at the Universidad Europea Research Lab and divided in two groups: a rugby group (n = 16) and a non-athletic women group (n = 16). The thickness of the TrAb, EO, IO, RA, and IRD were assessed by USI in both groups. Results: There were statistically significant differences for the ultrasound evaluation thickness of the right TrAb (p = 0.011; d = 0.10), EO (p = 0.045; d = 0.74), IO (p = 0.003; d = 1.32), and RA (p = 0.001; d = 1.38) showing a thickness increase for the rugby group with respect to the control group. For the IRD thickness, there were no significant differences (p > 0.05) between groups. Conclusions: An increased TrAb, IO, EO, and RA thickness may be shown in female rugby players versus non-athletic women. Nevertheless, statistically relevant differences were not found for the IRD between both groups.


1990 ◽  
Vol 258 (2) ◽  
pp. C344-C351 ◽  
Author(s):  
H. Schmidt ◽  
G. Wegener

White skeletal muscle of crucian carp contains a single isoenzyme of glycogen phosphorylase, which was purified approximately 300-fold to a specific activity of approximately 13 mumol.min-1.mg protein-1 (assayed in the direction of glycogen breakdown at 25 degrees C). Tissue extracts of crucian muscle produced three distinct peaks of phosphorylase activity when separated on DEAE-Sephacel. Peaks 1 and 3 were identified, in terms of kinetic properties and by interconversion experiments, as phosphorylase b and a, respectively. Peak 2 was shown to be a phospho-dephospho hybrid. The three interconvertible forms of phosphorylase were purified and shown to be dimeric molecules at 20 degrees C. At 5 degrees C, a and the hybrid tended to form tetramers. The Mr of the subunit was estimated to be 96,400 from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The hybrid is kinetically homogeneous, and its kinetic properties are intermediate between those of b and a forms. The b, hybrid, and a forms of phosphorylase can be isolated from rapidly frozen muscle of crucian but in different proportions, depending on whether fish were anesthetized or forced to muscular activity for 20 s. Muscle of anesthetized crucian had 36, 36, and 28% of phosphorylase b, hybrid, and a forms, respectively, whereas the corresponding values for exercised fish were 12, 37, and 51%. Results suggest that three interconvertible forms of phosphorylase exist simultaneously in crucian muscle and that hybrid phosphorylase is active in contracting muscle in vivo.


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