scholarly journals Bite-to-bite variation of muscular activity in cats

1990 ◽  
Vol 151 (1) ◽  
pp. 1-19
Author(s):  
C. Gans ◽  
G. C. Gorniak ◽  
W. K. Morgan
Keyword(s):  
Muscle Activity ◽  
Neural Control ◽  
Muscular Activity ◽  
Relative Magnitude ◽  
Emg Activity ◽  
Jaw Movements ◽  
Food Texture

Changes in electromyographic (EMG) activity between successive bites in the jaw-closing muscles of cats are described for the reduction of food with different textures. Plots of these data suggest, and statistics confirm, that one cannot predict the magnitude of EMG activity from one bite to the next, but that predicting the direction of change in EMG activity (i.e. increases or decreases) may be possible, given the relative magnitude of a bite. The patterns observed also show that the degree of variability between masticatory cycles differs among the jaw-closing muscles and with food texture. These patterns of muscle activity are related to the neural control of jaw movements.

scholarly journals Spatiotemporal distribution of location and object effects in the electromyographic activity of upper extremity muscles during reach-to-grasp

2016 ◽  
Vol 115 (6) ◽  
pp. 3238-3248 ◽  
Author(s):  
Adam G. Rouse ◽  
Marc H. Schieber
Keyword(s):  
Upper Extremity ◽  
Muscle Activity ◽  
Neural Control ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Proximal Muscle ◽  
Reach To Grasp ◽  
Distal Muscle ◽  
The Subject ◽  
Later Phase

In reaching to grasp an object, proximal muscles that act on the shoulder and elbow classically have been viewed as transporting the hand to the intended location, while distal muscles that act on the fingers simultaneously shape the hand to grasp the object. Prior studies of electromyographic (EMG) activity in upper extremity muscles therefore have focused, by and large, either on proximal muscle activity during reaching to different locations or on distal muscle activity as the subject grasps various objects. Here, we examined the EMG activity of muscles from the shoulder to the hand, as monkeys reached and grasped in a task that dissociated location and object. We quantified the extent to which variation in the EMG activity of each muscle depended on location, on object, and on their interaction—all as a function of time. Although EMG variation depended on both location and object beginning early in the movement, an early phase of substantial location effects in muscles from proximal to distal was followed by a later phase in which object effects predominated throughout the extremity. Interaction effects remained relatively small. Our findings indicate that neural control of reach-to-grasp may occur largely in two sequential phases: the first, serving to project the entire upper extremity toward the intended location, and the second, acting predominantly to shape the entire extremity for grasping the object.

scholarly journals Patterns Of Circular And Radial Mantle Muscle Activity in Respiration and Jetting of the Squid Loligo Opalescens

1983 ◽  
Vol 104 (1) ◽  
pp. 97-109 ◽  
Author(s):  
JOHN M. GOSLINE ◽  
JOHN D. STEEVES ◽  
ANTHONY D. HARMAN ◽  
M. EDWIN DEMONT
Keyword(s):  
Muscle Activity ◽  
Circular Muscle ◽  
Muscular Activity ◽  
Mantle Cavity ◽  
Emg Activity ◽  
Small Contribution ◽  
Tissue Elasticity ◽  
Elastic Recoil ◽  
Loligo Opalescens ◽  
Muscle Groups

1. By simultaneously recording the electromyographic (EMG) activity of squid mantle muscles, changes in mantle cavity pressure and changes in mantle diameter, we have been able to distinguish the pattern of radial muscle activity from circular muscle activity, and in so doing were able to determine the functional role of these muscle groups in motor behaviours. 2. Three distinguishable phases of activity appear during escape jets: (i), hyper-inflation brought about by the contraction of the radial muscles; (ii), the jet powered by the contraction of circular muscles; and (iii), refilling powered largely by the elastic recoil of the mantle wall, but with a small contribution from the radial muscles. 3. Two distinctly different patterns of muscular activity were seen in respiratory movements. One pattern (pattern I) is powered by the radial muscles alone, while the other (pattern II) is powered by the circular muscles alone. In both modes of respiration, the muscles are apparently antagonized by tissue elasticity. 4. Thus, the storage of elastic energy in the connective tissue fibre-lattice of the mantle wall plays a very important role in both modes of squid movement.

scholarly journals Task-level feedback can explain temporal recruitment of spatially fixed muscle synergies throughout postural perturbations

2012 ◽  
Vol 107 (1) ◽  
pp. 159-177 ◽  
Author(s):  
Seyed A. Safavynia ◽  
Lena H. Ting
Keyword(s):  
Muscle Activity ◽  
Neural Control ◽  
Temporal Patterns ◽  
Emg Activity ◽  
Muscle Synergies ◽  
Muscle Coordination ◽  
Postural Responses ◽  
Temporal Features ◽  
Low Dimensional ◽  
Task Level

Recent evidence suggests that complex spatiotemporal patterns of muscle activity can be explained with a low-dimensional set of muscle synergies or M-modes. While it is clear that both spatial and temporal aspects of muscle coordination may be low dimensional, constraints on spatial versus temporal features of muscle coordination likely involve different neural control mechanisms. We hypothesized that the low-dimensional spatial and temporal features of muscle coordination are independent of each other. We further hypothesized that in reactive feedback tasks, spatially fixed muscle coordination patterns—or muscle synergies—are hierarchically recruited via time-varying neural commands based on delayed task-level feedback. We explicitly compared the ability of spatially fixed (SF) versus temporally fixed (TF) muscle synergies to reconstruct the entire time course of muscle activity during postural responses to anterior-posterior support-surface translations. While both SF and TF muscle synergies could account for EMG variability in a postural task, SF muscle synergies produced more consistent and physiologically interpretable results than TF muscle synergies during postural responses to perturbations. Moreover, a majority of SF muscle synergies were consistent in structure when extracted from epochs throughout postural responses. Temporal patterns of SF muscle synergy recruitment were well-reconstructed by delayed feedback of center of mass (CoM) kinematics and reproduced EMG activity of multiple muscles. Consistent with the idea that independent and hierarchical low-dimensional neural control structures define spatial and temporal patterns of muscle activity, our results suggest that CoM kinematics are a task variable used to recruit SF muscle synergies for feedback control of balance.

Behavior of Jaw Muscle Spindle Afferents During Cortically Induced Rhythmic Jaw Movements in the Anesthetized Rabbit

1999 ◽  
Vol 82 (5) ◽  
pp. 2633-2640 ◽  
Author(s):  
O. Hidaka ◽  
T. Morimoto ◽  
T. Kato ◽  
Y. Masuda ◽  
T. Inoue ◽  
...  
Keyword(s):  
Firing Rate ◽  
Muscle Spindle ◽  
Muscle Activity ◽  
Muscle Spindles ◽  
Emg Activity ◽  
Spatiotemporal Pattern ◽  
Digastric Muscle ◽  
Dependent Manner ◽  
Jaw Movements ◽  
Jaw Opening

The regulation by muscle spindles of jaw-closing muscle activity during mastication was evaluated in anesthetized rabbits. Simultaneous records were made of the discharges of muscle spindle units in the mesencephalic trigeminal nucleus, masseter and digastric muscle activity (electromyogram [EMG]), and jaw-movement parameters during cortically induced rhythmic jaw movements. One of three test strips of polyurethane foam, each of a different hardness, was inserted between the opposing molars during the jaw movements. The induced rhythmic jaw movements were crescent shaped and were divided into three phases: jaw-opening, jaw-closing, and power. The firing rate of muscle spindle units during each phase increased after strip application, with a tendency for the spindle discharge to be continuous throughout the entire chewing cycle. However, although the firing rate did not change during the jaw-opening and jaw-closing phases when the strip hardness was altered, the firing rate during the power phase increased in a hardness-dependent manner. In addition, the integrated EMG activity, the duration of the masseteric bursts, and the minimum gape increased with strip hardness. Spindle discharge during the power phase correlated with jaw-closing muscle activity, implying that the change in jaw-closing muscle activity associated with strip hardness was caused by increased spindle discharge produced through insertion of a test strip. The increased firing rate during the other two phases may be involved in a long-latency spindle feedback. This could contribute to matching the spatiotemporal pattern of the central pattern generator to that of the moving jaw.

Abdominal muscle activity during speech production

1988 ◽  
Vol 65 (6) ◽  
pp. 2656-2664 ◽  
Author(s):  
J. D. Hoit ◽  
B. L. Plassman ◽  
R. W. Lansing ◽  
T. J. Hixon
Keyword(s):  
Speech Production ◽  
Supine Position ◽  
Muscle Activity ◽  
Neural Control ◽  
Current Knowledge ◽  
Body Position ◽  
Abdominal Muscle ◽  
Upright Position ◽  
Emg Activity ◽  
Tidal Breathing

Abdominal muscle activity was investigated during resting tidal breathing and speech production in upright and supine body positions in five male and five female young adult subjects. Results showed that patterns of abdominal electromyographic (EMG) activity were highly dependent on body position. Data for resting tidal breathing resembled those of previous investigations and revealed one sex-related finding. Data for speech production indicated that the lateral region of the abdomen was highly active in the upright position and occasionally active in the supine position. In the upright position, lateral EMG levels during speech production were characterized by generally higher levels in the lower than upper lateral sites and were almost always higher than during resting tidal breathing. In the supine position, EMG levels during speech production occasionally exceeded those associated with resting tidal breathing but were substantially lower than those associated with upright speech production. Abdominal EMG activity was most prevalent during loud speech production and during speech produced at low lung volumes. Findings are discussed in relation to current knowledge of respiratory mechanics and neural control.

scholarly journals Changes in muscle activity during the flexion and extension phases of arm cycling as an effect of power output are muscle-specific

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9759
Author(s):  
Carla P. Chaytor ◽  
Davis Forman ◽  
Jeannette Byrne ◽  
Angela Loucks-Atkinson ◽  
Kevin E. Power
Keyword(s):  
Neural Plasticity ◽  
Power Output ◽  
Muscle Activity ◽  
Neural Control ◽  
Peak Power Output ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Arm Cycling ◽  
Extensor Carpi Radialis ◽  
Flexion And Extension

Arm cycling is commonly used in rehabilitation settings for individuals with motor impairments in an attempt to facilitate neural plasticity, potentially leading to enhanced motor function in the affected limb(s). Studies examining the neural control of arm cycling, however, typically cycle using a set cadence and power output. Given the importance of motor output intensity, typically represented by the amplitude of electromyographic (EMG) activity, on neural excitability, surprisingly little is known about how arm muscle activity is modulated using relative workloads. Thus, the objective of this study was to characterize arm muscle activity during arm cycling at different relative workloads. Participants (n = 11) first completed a 10-second maximal arm ergometry sprint to determine peak power output (PPO) followed by 11 randomized trials of 20-second arm cycling bouts ranging from 5–50% of PPO (5% increments) and a standard 25 W workload. All submaximal trials were completed at 60 rpm. Integrated EMG amplitude (iEMG) was assessed from the biceps brachii, brachioradialis, triceps brachii, flexor carpi radialis, extensor carpi radialis and anterior deltoid of the dominant arm. Arm cycling was separated into two phases, flexion and extension, relative to the elbow joint for all comparisons. As expected, iEMG amplitude increased during both phases of cycling for all muscles examined. With the exception of the triceps brachii and extensor carpi radialis, iEMG amplitudes differed between the flexion and extension phases. Finally, there was a linear relationship between iEMG amplitude and the %PPO for all muscles during both elbow flexion and extension.

Myoelectric Activity Differences in Three Learning Sessions

2002 ◽  
Vol 16 (2) ◽  
pp. 92-96
Author(s):  
Tiina Ritvanen ◽  
Reijo Koskelo ◽  
Osmo H„nninen
Keyword(s):  
High School Students ◽  
Muscle Activity ◽  
Muscle Tension ◽  
Emg Activity ◽  
Traditional Learning ◽  
Myoelectric Activity ◽  
School Students ◽  
Language Laboratory ◽  
Upper Trapezius ◽  
Muscle Groups

Abstract This study follows muscle activity in three different learning sessions (computer, language laboratory, and normal classroom) while students were studying foreign languages. Myoelectric activity was measured in 21 high school students (10 girls, 11 boys, age range 17-20 years) by surface electromyography (sEMG) from the upper trapezius and frontalis muscles during three 45-min sessions. Root mean square (RMS) average from both investigated muscles was calculated. The EMG activity was highest in both muscle groups in the computer-aided session and lowest in the language laboratory. The girls had higher EMG activity in both investigated muscle groups in all three learning situations. The measured blood pressure was highest at the beginning of the sessions, decreased within 10 min, but increased again toward the end of the sessions. Our results indicate that the use of a computer as a teaching-aid evokes more constant muscle activity than the traditional learning situations. Since muscle tension can have adverse health consequences, more research is needed to determine optimal classroom conditions, especially when technical aids are used in teaching.

scholarly journals Rostrocaudal Distribution of the C-Fos-Immunopositive Spinal Network Defined by Muscle Activity during Locomotion

2021 ◽  
Vol 11 (1) ◽  
pp. 69
Author(s):  
Natalia Merkulyeva ◽  
Vsevolod Lyakhovetskii ◽  
Aleksandr Veshchitskii ◽  
Oleg Gorskii ◽  
Pavel Musienko
Keyword(s):  
Spinal Cord ◽  
Locomotor Activity ◽  
Control Systems ◽  
Muscle Activity ◽  
Knee Extensors ◽  
Emg Activity ◽  
Lumbosacral Spinal Cord ◽  
Adductor Muscles ◽  
Spinal Network ◽  
Hip Flexor

The optimization of multisystem neurorehabilitation protocols including electrical spinal cord stimulation and multi-directional tasks training require understanding of underlying circuits mechanisms and distribution of the neuronal network over the spinal cord. In this study we compared the locomotor activity during forward and backward stepping in eighteen adult decerebrated cats. Interneuronal spinal networks responsible for forward and backward stepping were visualized using the C-Fos technique. A bi-modal rostrocaudal distribution of C-Fos-immunopositive neurons over the lumbosacral spinal cord (peaks in the L4/L5 and L6/S1 segments) was revealed. These patterns were compared with motoneuronal pools using Vanderhorst and Holstege scheme; the location of the first peak was correspondent to the motoneurons of the hip flexors and knee extensors, an inter-peak drop was presumably attributed to the motoneurons controlling the adductor muscles. Both were better expressed in cats stepping forward and in parallel, electromyographic (EMG) activity of the hip flexor and knee extensors was higher, while EMG activity of the adductor was lower, during this locomotor mode. On the basis of the present data, which showed greater activity of the adductor muscles and the attributed interneuronal spinal network during backward stepping and according with data about greater demands on postural control systems during backward locomotion, we suppose that the locomotor networks for movements in opposite directions are at least partially different.

Respiratory Activity of the Rat Posterior Cricoarytenoid Muscle

1997 ◽  
Vol 106 (11) ◽  
pp. 897-901 ◽  
Author(s):  
Robert G. Berkowitz ◽  
John Chalmers ◽  
Qi-Jian Sun ◽  
Paul M. Pilowsky
Keyword(s):  
Phrenic Nerve ◽  
Muscle Activity ◽  
Electrophysiological Study ◽  
Emg Activity ◽  
Diaphragmatic Muscle ◽  
Posterior Cricoarytenoid Muscle ◽  
Inspiratory Activity ◽  
Intramuscular Nerve ◽  
Posterior Cricoarytenoid ◽  
Nerve Discharge

An anatomic and electrophysiological study of the rat posterior cricoarytenoid (PCA) muscle is described. The intramuscular nerve distribution of the PCA branch of the recurrent laryngeal nerve was demonstrated by a modified Sihler's stain. The nerve to the PCA was found to terminate in superior and inferior branches with a distribution that appeared to be confined to the PCA muscle. Electromyography (EMG) recordings of PCA muscle activity in anesthetized rats were obtained under stereotaxic control together with measurement of phrenic nerve discharge. A total of 151 recordings were made in 7 PCA muscles from 4 rats. Phasic inspiratory activity with a waveform similar to that of phrenic nerve discharge was found in 134 recordings, while a biphasic pattern with both inspiratory and post-inspiratory peaks was recorded from random sites within the PCA muscle on 17 occasions. The PCA EMG activity commenced 24.6 ± 2.2 milliseconds (p < .0001) before phrenic nerve discharge. The results are in accord with findings of earlier studies that show that PCA muscle activity commences prior to inspiratory airflow and diaphragmatic muscle activity. The data suggest that PCA and diaphragm motoneurons share common or similar medullary pre-motoneurons. The earlier onset of PCA muscle activity may indicate a role for medullary pre-inspiratory neurons in initiating PCA activity.

scholarly journals Electromyographic Analysis of Traditional and Nontraditional Abdominal Exercises: Implications for Rehabilitation and Training

2006 ◽  
Vol 86 (5) ◽  
pp. 656-671 ◽  
Author(s):  
Rafael F Escamilla ◽  
Eric Babb ◽  
Ryan DeWitt ◽  
Patrick Jew ◽  
Peter Kelleher ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Latissimus Dorsi ◽  
Rectus Femoris ◽  
Rectus Abdominis ◽  
Oblique Muscle ◽  
Emg Activity ◽  
Internal Oblique ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle ◽  
Roll Out

Abstract Background and Purpose. Performing nontraditional abdominal exercises with devices such as abdominal straps, the Power Wheel, and the Ab Revolutionizer has been suggested as a way to activate abdominal and extraneous (nonabdominal) musculature as effectively as more traditional abdominal exercises, such as the crunch and bent-knee sit-up. The purpose of this study was to test the effectiveness of traditional and nontraditional abdominal exercises in activating abdominal and extraneous musculature. Subjects. Twenty-one men and women who were healthy and between 23 and 43 years of age were recruited for this study. Methods. Surface electromyography (EMG) was used to assess muscle activity from the upper and lower rectus abdominis, external and internal oblique, rectus femoris, latissimus dorsi, and lumbar paraspinal muscles while each exercise was performed. The EMG data were normalized to maximum voluntary muscle contractions. Differences in muscle activity were assessed by a 1-way, repeated-measures analysis of variance. Results. Upper and lower rectus abdominis, internal oblique, and latissimus dorsi muscle EMG activity were highest for the Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees. External oblique muscle EMG activity was highest for the Power Wheel (pike, knee-up, and roll-out) and hanging knee-up with straps. Rectus femoris muscle EMG activity was highest for the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up. Lumbar paraspinal muscle EMG activity was low and similar among exercises. Discussion and Conclusion. The Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees not only were the most effective exercises in activating abdominal musculature but also were the most effective in activating extraneous musculature. The relatively high rectus femoris muscle activity obtained with the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up may be problematic for some people with low back problems.

Sign in / Sign up

Export Citation Format

Share Document