Differential Influence of a Visual Flow Pattern on Emg-Activity of Antagonistic Leg Muscles During Unstable Stance

1995 ◽  
pp. 139-145
Author(s):  
V. Dietz ◽  
M. Schubert ◽  
W. Berger
Keyword(s):  
Flow Pattern ◽  
Emg Activity ◽  
Leg Muscles ◽  
Visual Flow

The Relationship between Integrated EMG and Oxygen Uptake during Treadmill and Bicycle Exercise

1976 ◽  
Vol 20 (23) ◽  
pp. 548-551
Author(s):  
T. Fukunaga ◽  
K. Yuasa ◽  
M. Kobayashi ◽  
T. Miyagawa ◽  
H. Fujimatsu ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Correlation Coefficient ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Treadmill Walking ◽  
Emg Activity ◽  
Bicycle Exercise ◽  
Leg Muscles ◽  
Integrated Emg ◽  
Muscle Groups

The aim of this study is to measure the integrated EMG in relation to the oxygen uptake during submaximal treadmill and bicycle exercises. Seven healthy adult subjects performed five minute exercise at three different submaximal work intensities on the same day. The EMG activity in right thigh and leg muscles was measured from m. rectus femoris, m. biceps femoris, m. tibialis anterior and m. gastrocnemius by means of four pairs of surface electrodes sealed with collodion to the skin at a distance of 3 cm apart over the belly of muscles. The EMG activity was not likely modified by the possible fatigue during 5 minutes submaximal exercise in this experiment. In the treadmill walking, there was a rectilinear relationship between integrated EMG activity from four muscle groups and percent of VO2max. On the bicycle exercise the correlation coefficient between them was generally lower than that on the treadmill walking. The product of integrated EMG and volume of the same muscle groups was considerably linearly related to oxygen uptake during treadmill and bicycle exercise (the correlation coefficient was 0.945, p < 0.001 in treadmill and 0.710, p < 0.001 in bicycle).

scholarly journals Electromyographic activity of the vastus medialis and gastrocnemius implicates a slow stretch-shortening cycle during rowing in the field

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Steffen Held ◽  
Tobias Siebert ◽  
Lars Donath
Keyword(s):  
Performance Enhancement ◽  
Muscular Activity ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Vastus Medialis ◽  
Leg Muscles ◽  
Rowing Performance ◽  
Specific Muscle ◽  
Two Phases ◽  
Activation Phase

Abstract The consideration of the temporal and electromyographic (EMG) characteristics of stretch-shortening cycles (SSC) are crucial for the conceptualization of discipline-specific testing and training. Since leg muscles are first stretched (eccentric) and then contracted (concentric) during rowing, it can be assumed that the entire muscle tendon complex performs a SSC. Thus, it should be elucidated whether the rowing cycle can be attributed to either a slow or fast SSC. Therefore, EMG of the vastus medialis and gastrocnemius were captured (n = 10, 22.8 ± 3.1 years, 190 ± 6 cm, 82.1 ± 9.8 kg) during (single scull) rowing and subsequently compared to typical slow (countermovement jump, CMJ) and fast (drop jump, DJ) SSCs. The elapsed time between the EMG onset and the start of the eccentric phase was monitored. The pre-activation phase (PRE, before the start of the eccentric phase) and the reflex-induced activation phase (RIA 30–120 ms after the start of the eccentric phase) have been classified. Notable muscular activity was observed during DJ before the start of the eccentric phase (PRE) as well as during RIA. In contrast, neither CMJ nor rowing revealed any EMG-activity in these two phases. Interestingly, CMJ and race-specific rowing showed an EMG-onset during the eccentric phase. We conclude that rowing is more attributable to a slow SSC and implies that fast SSC does not reflect discipline specific muscle action and could hamper rowing-performance-enhancement.

EMG, Force, and Power Analysis of Sprint-Specific Strength Exercises

1994 ◽  
Vol 10 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Antti Mero ◽  
Paavo V. Komi
Keyword(s):  
Muscle Power ◽  
Emg Activity ◽  
Specific Strength ◽  
Leg Muscles ◽  
Strength Exercises ◽  
Stride Rate ◽  
Emg Patterns ◽  
Force Time ◽  
The Right ◽  
Resultant Forces

This study was undertaken to compare force-time characteristics, muscle power, and electromyographic (EMG) activities of the leg muscles in maximal sprinting and in selected bounding and jumping exercises. Seven male sprinters performed maximal bounding (MB), maximal stepping (MS), maximal hopping with the right (MHR) and left (MHL) legs, and maximal sprint running (MR). These “horizontal” exercises and running were performed on a force platform. EMG activity was telemetered unilaterally from five leg muscles during each trial. The results indicated significant (p < .001) differences among the studied exercises in velocity, stride length, stride rate, flight time, and contact time. Also, significant differences were noticed in reactive forces (p < .01-.001) and power (p < .01) among the performances, whereas only insignificant differences were observed in EMG patterns. The average resultant forces during the braking and propulsion phases in MS, MHR, and MHL were greater (p < .001) than in MR and MB. Stepping and hopping are cyclic and sprint-specific and may be used as strength exercises for sprinters because of great strength demand.

Quantitative analysis of surface EMG activity of cranial and leg muscles across sleep stages in human

2006 ◽  
Vol 117 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Kazuo Okura ◽  
Takafumi Kato ◽  
Jacques Y. Montplaisir ◽  
Barry J. Sessle ◽  
Gilles J. Lavigne
Keyword(s):  
Quantitative Analysis ◽  
Surface Emg ◽  
Emg Activity ◽  
Sleep Stages ◽  
Leg Muscles

Spinal neuronal dysfunction after deprivation of supraspinal input

2020 ◽  
pp. 83-94
Author(s):  
Michèle Hubli ◽  
Volker Dietz
Keyword(s):  
Neural Plasticity ◽  
Neuronal Networks ◽  
Spinal Reflex ◽  
Emg Activity ◽  
Sensory Cues ◽  
Chronic Stage ◽  
Functional Changes ◽  
Leg Muscles ◽  
Proprioceptive Input ◽  
Cord Injury

A central nervous system lesion can lead to remote structural and functional changes which may limit functional recovery. For example, after a spinal cord injury (SCI) structural and functional alterations of spinal neuronal networks take place: in the first weeks after an SCI, neither locomotor nor spinal reflex (SR) activity can be evoked. Once spinal shock has resolved, an early SR component can be re-evoked and locomotor electromyography (EMG) activity re-appears when appropriate proprioceptive input is provided. In a more chronic stage of SCI alterations in SR components are accompanied by a decline of EMG amplitude in the leg muscles during assisted locomotion. According to rodent experiments it is assumed that the deprivation of supraspinal input and the lack of meaningful proprioceptive input to spinal neuronal networks account for such alterations. A critical combination of sensory cues through physiological training strategies might prevent the development of an undirected neural plasticity.

scholarly journals Preparatory Postural Adjustments in Parkinsonian Patients with Postural Instability

1995 ◽  
Vol 22 (2) ◽  
pp. 126-135 ◽  
Author(s):  
Robert G. Lee ◽  
Ida Tonolli ◽  
Francois Viallet ◽  
Roslyn Aurenty ◽  
Jean Massion
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Normal Subjects ◽  
Postural Instability ◽  
Emg Activity ◽  
Foot Pressure ◽  
Postural Adjustments ◽  
Leg Muscles ◽  
Sequence Of Events ◽  
Reaction Forces

AbstractBackground:Postural instability is a common problem in patients with Parkinson’s disease. This paper reports results of a study undertaken to investigate some of the possible mechanisms responsible for this instability.Methods:Preparatory postural adjustments associated with a lateral leg raising task were studied in five parkinsonian patients and four age-matched controls. Recordings included ground reaction forces, kinematics, and surgace EMG activity from multiple leg muscles.Results:In normal subjects there was a well-defined sequence of events preceding the onset of leg elevation, beginning with a transfer of centre of foot pressure (CP), initially toward the moving leg and then back to the support side, followed by displacement of the trunk toward the support side. In the more severely affected parkinsonian patients, the amplitude of the the initial displacement of CP was markedly reduced. The interval between the earliest force changes and the onset of leg elevation was prolonged and the relative timing of the kenematic adjustments during this interval was disrupted. In addition the alternating burst and periods of inhibition observed in the EMG recordings from the normal subjects were replaced by continuous tonic EMG activity.Conclusions:These observations suggest that abnormalities in programming preparatory postural adjustments may contribute to postural instability in some patients with advanced Parkinson’s disease.

EMG Activity of Leg Muscles with Knee Pain during Islamic Prayer (Salat)

2019 ◽  
Author(s):  
Mohammad Fazle Rabbi ◽  
Nurul Wahidah Arshad ◽  
Kamarul H. Ghazali ◽  
Rohana Abdul Karim ◽  
Mohd Zamri Ibrahim ◽  
...  
Keyword(s):  
Knee Pain ◽  
Emg Activity ◽  
Leg Muscles ◽  
Islamic Prayer

The effect of orthotics on intersegmental foot kinematics and the EMG activity of select lower leg muscles

The Foot ◽  
2015 ◽  
Vol 25 (4) ◽  
pp. 206-214 ◽  
Author(s):  
Juan C. Garbalosa ◽  
Bruce Elliott ◽  
Richard Feinn ◽  
Ryan Wedge
Keyword(s):  
Lower Leg ◽  
Emg Activity ◽  
Foot Kinematics ◽  
Leg Muscles

Motor Patterns in Human Walking and Running

2006 ◽  
Vol 95 (6) ◽  
pp. 3426-3437 ◽  
Author(s):  
G. Cappellini ◽  
Y. P. Ivanenko ◽  
R. E. Poppele ◽  
F. Lacquaniti
Keyword(s):  
Muscle Activation ◽  
Human Locomotion ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Step Cycle ◽  
Motor Patterns ◽  
Leg Muscles ◽  
Shoulder Muscles ◽  
The Difference ◽  
Muscle Activations

Despite distinct differences between walking and running, the two types of human locomotion are likely to be controlled by shared pattern-generating networks. However, the differences between their kinematics and kinetics imply that corresponding muscle activations may also be quite different. We examined the differences between walking and running by recording kinematics and electromyographic (EMG) activity in 32 ipsilateral limb and trunk muscles during human locomotion, and compared the effects of speed (3–12 km/h) and gait. We found that the timing of muscle activation was accounted for by five basic temporal activation components during running as we previously found for walking. Each component was loaded on similar sets of leg muscles in both gaits but generally on different sets of upper trunk and shoulder muscles. The major difference between walking and running was that one temporal component, occurring during stance, was shifted to an earlier phase in the step cycle during running. These muscle activation differences between gaits did not simply depend on locomotion speed as shown by recordings during each gait over the same range of speeds (5–9 km/h). The results are consistent with an organization of locomotion motor programs having two parts, one that organizes muscle activation during swing and another during stance and the transition to swing. The timing shift between walking and running reflects therefore the difference in the relative duration of the stance phase in the two gaits.

Spinal neuronal dysfunction after deprivation of supraspinal input

2015 ◽  
pp. 67-75
Author(s):  
Michèle Hubli ◽  
Volker Dietz
Keyword(s):  
Spinal Cord ◽  
Spinal Reflexes ◽  
Emg Activity ◽  
Neuronal Dysfunction ◽  
Sensory Cues ◽  
Neuronal Function ◽  
Chronic Stage ◽  
Leg Muscles ◽  
Cord Injury ◽  
Locomotor Ability

The comprehension of basic spinal neuronal alterations after central nervous system lesions, such as spinal cord injury (SCI) or stroke, enables us to optimize rehabilitative approaches for affected subjects. Adverse changes in spinal neuronal function are best investigated by recordings of spinal reflexes (SR) and locomotor electromyography (EMG). In the first few weeks after an SCI, neither locomotor nor SR activity can be evoked. Once spinal shock has resolved, an early SR component can be re-evoked and locomotor EMG activity reappears in response to appropriate peripheral input. In a more chronic stage of SCI, however, alterations in SR components are accompanied by a decline of EMG amplitude in the leg muscles during assisted locomotion. It is assumed that not only the deprivation of supraspinal input but also of the lack of meaningful proprioceptive input to spinal neuronal networks account for such alterations in chronic immobilized individuals with SCI..A critical combination of sensory cues through appropriate training strategies seems to prevent the development of spinal neuronal dysfunction and to improve locomotor ability.

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