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Results 551 - 600 of 681
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Dahlström L - - 1989
Serial registrations of integrated unilateral surface masseter EMG were performed in eight healthy subjects in the rest position, during controlled gentle biting and during maximal clenching at five different sessions in order to analyse the variability. The recording conditions were standardised. The EMG activity for the group did not differ ...
Challis R E - - 1989
The intestinal EMG obtained from chronically implanted electrodes in canine preparations provides for the evaluation of intestinal motor activity and its control. The basic electrical rhythm (BER) and spike components on the EMG signal provide evidence of control activity and a measure of contraction intensity, respectively. A hardware system is ...
Redenbaugh M A - - 1989
Surface electromyographic (EMG) signals were detected from the laryngeal area of 7 normal and 7 vocally hyperfunctional speakers during rest, two resisted-force maneuvers, vowel production, and connected speech. Vowel fundamental frequency, absolute and relative period perturbation, laryngeal-palpation ratings, and harshness ratings were acquired as well. The two groups differed significantly ...
Lavender S A - - 1989
The effect of warning time (preview) and task symmetry on the trunk muscular response to sudden loading conditions was investigated. Eleven subjects were asked to catch falling weights with four levels of preview (0, 100, 200, and 400 ms) in saggitally symmetric posture and asymmetric posture. For each of the ...
Seroussi R - - 1989
We have designed a real-time microcomputerized muscle fatigue monitor based on the median frequency shift of the electromyographic signal, computed via the fast Fourier transform. For the ten subjects performing an isotonic and isometric trunk extension task on two separate days, preliminary results suggest a repeatable linear decrease in median ...
Dollins A B - - 1989
Eleven subjects were asked to silently read slides of the letters "P" and "T," and to view meaningless control slides similarly as they were presented visually. One-eighth-second electromyographic excerpts were sampled from the baseline and response periods. The data were then transformed into the frequency domain for inferential analyses. The ...
Wallace G K - - 1989
The patterns of EMG activity in the biceps and triceps muscles were recorded during horizontal oscillatory movements of the forearm. Subjects showed increased frequency of oscillation as they voluntarily reduced movement amplitude. EMG burst duration was significantly correlated with wavelength of oscillation in every case. In almost half the cases ...
Pedotti A A Centro di Bioingeneria, Politecnico-Fnd. Pro Juventute Don Gnocchi, Milan, - - 1989
Fast backward trunk movements are accompanied by hip, knee and ankle rotation which compensate for the backward shift of the center of gravity. The electromyographic pattern associated with the performance of these movements and the associated synergies consists of a fairly synchronous activation of the prime mover (erectores spinae) and ...
Shochina M - - 1989
The effects of various filter settings on the electrophysiological behavior of the development of muscular fatigue were studied. Eleven healthy volunteers were examined during isometric contraction of biceps brachii and rectus femoris against a constant load until fatigue occurred. The electrical activity was taped and computer processing was carried out ...
Schotland J L JL Neuroscience Institute, Northwestern University Medical School, Chicago, IL - - 1989
We investigated the hypotheses (1) that the initial flexion part of the wipe reflex elicited in the spinalized frog has the same EMG pattern for wipes to different target locations (Berkinblit et al. 1986), thereby reducing the complexity of the control of this task, and (2) that this initial flexion ...
Fujita M - - 1988
The effect of passive elbow motions on electromyographic reaction times (EMG-RTs) of the biceps brachii for elbow flexion and the triceps for elbow extension was investigated in 8 normal subjects, using a choice-RT task, in which the subject was uncertain about the response direction to perform until the arrival of ...
Mojica J A - - 1988
Under simple- and choice-RT conditions, the biceps brachii muscle was examined in 8 healthy male subjects to determine how the temporal and spatial characteristics of elbow flexion and forearm supination differed at the initial phase of EMG activity and whether preparation or the presence of response uncertainty influenced the EMG ...
Suzuki S - - 1988
In quadrupeds, an electrically induced, moderate to high intensity brief muscle contraction potentiates autogenetic excitation and leads to enhanced recruitment and/or tonic firing frequency of alpha-motor neurons. To determine if similar adaptations occur in humans, single motor units (SMUs) and surface electromyographic activity (EMG) were recorded from the right biceps ...
Diener H C - - 1988
1. The role of sensory information in shaping muscle activation patterns to postural perturbations in humans was investigated by varying velocity, amplitude, or duration of the perturbing stimulus. Ten normal subjects were exposed to 120 backward translations of the support surface under conditions of varying velocities (10-35 cm/s, constant amplitude), ...
Kinugasa T - - 1988
Electromyographic reaction times (EMG-RTs) of the right biceps brachii muscle were examined for two movement patterns, elbow flexion and forearm supination, in 8 healthy male subjects under simple and complex RT conditions with varied preparatory intervals (PIs): 0, 200, 400, 600, and 800 msec. In the simple RT condition, the ...
Poulton E C - - 1988
Between the 1960s and the 1980s there has been an increase in the Journal of Motor Behavior (JMB) of neuromuscular theories of control, of continuous records showing amplitude or force over time, and of electromyograms (EMGs). Investigations of the advance programming of complex movements have also increased. There has been ...
Aniss A M - - 1988
1. This study examined the relationship between the perceived heaviness of a weight and reflexes acting on the motoneurones required for the contraction. The perceived heaviness of low (100 g) and high (500 g) reference weights lifted by the first dorsal interosseous muscle was estimated using a matching task. Weights ...
Fitting J W - - 1988
To assess rib cage muscle fatigue and its relationship to diaphragmatic fatigue, we recorded the electromyogram (EMG) of the parasternal intercostals (PS), sternocleidomastoid (SM), and platysma with fine wire electrodes and the EMG of the diaphragm (DI) with an esophageal electrode. Six normal subjects were studied during inspiratory resistive breathing. ...
Seidel H - - 1988
5 healthy males were exposed to vertical sinusoidal whole body vibration (WBV) at 5 frequencies (F1 = 0.315 Hz, F2 = 0.63 Hz, F3 = 1.25 Hz, F4 = 2.5 Hz, F5 = 5.0 Hz) and 2 intensities (I1 = 1.2 ms-2 rms, F1-F5; I2 = 2.0 ms-2 rms, F2-F5). ...
Gerdle B - - 1988
This study investigated how position in the range of motion influences the power spectral density function during static shoulder forward flexion. 23 healthy females (20-30 years) volunteered as subjects. They performed maximum static shoulder forward flexions in three positions: 45, 65 and 90 degrees of shoulder flexion. An isokinetic dynamometer ...
Arendt-Nielsen L - - 1988
In 5 healthy male subjects the changes in muscle fibre conduction velocity, mean power frequency, mean EMG voltage, and force in the quadriceps were measured during submaximal fatiguing contractions, ranging from 60 to 100% of maximum force. Surface EMG was recorded from vastus lateralis. The analysis was divided into 2 ...
Bradley N S - - 1988
Neuromuscular patterns associated with the development of hindlimb stepping behaviors were studied from birth to postnatal day 60 in normal kittens. Hindlimb muscles were chronically implanted with EMG electrodes at birth to characterize interlimb coordination and intralimb synergies during development of overground and treadmill stepping. Airstepping was also examined but ...
Clark G T - - 1988
The effect of sustained isometric contraction on surface electromyograph (EMG) and force signals derived from these muscles was examined. Premolar-molar region force was measured with a small unilaterally positioned force transducer. Subjects produced and sustained 25, 50, 75 and 100 per cent isometric force levels, and measurements were made at ...
Watson B C - - 1988
The author discusses the mechanisms of speech production, focusing on the measurement of its motor aspects. He examines the multiple representation levels at which physiological events that underlie speech production can be investigated, and examines measurement of neuromuscular activity, structure movement (e.g. kinematics and dynamics), aerodynamic phenomena, and/or the acoustic ...
Pajntar M - - 1988
The role of the smooth cervical muscle has not yet been sufficiently explored. For that reason cervical EMG was measured during induced labour of several primiparas and multiparas. Three spiral electrodes were placed on the cervix in order to measure the EMG in the longitudinal and circular direction referred to ...
Blaschak M J MJ Department of Biomedical Engineering, Northwestern University, Chicago, IL - - 1988
Force and electromyogram (EMG) responses of the medial gastrocnemius muscle were assessed during isometric contractions in 8 decerebrate cat preparations, before and after acute dorsal hemisection of the spinal cord at the T12 level. The measures derived included the relation between static force and mean rectified EMG, the EMG amplitude ...
Moritani T - - 1987
Motor unit activity was investigated in the biceps brachii of twelve men during concentric (CC) and eccentric (EC) contractions by means of computer aided intramuscular spike amplitude-frequency (ISAF) histograms and surface EMG frequency power spectral analyses. Simultaneous recordings of the intramuscular and surface EMG signals were made during both types ...
Tanii K - - 1987
The silent period and a rhythmic slower wave in EMG appear preceding a rapid voluntary movement (Tanii 1984). The present study was performed to investigate temporal relationships of the EMG changes preceding movement to premovement cortical potential shifts, in order to clarify whether the EMG changes are related to preparation ...
Stokes I A - - 1987
The integrated surface electromyogram (IEMG) of the lumbar erectores spinae and the torque generated were simultaneously recorded from 27 healthy subjects in the standing posture while they pulled isometrically against resistance provided by a harness around the shoulders. The IEMG-torque ratio (efficiency of electrical activity, or EEA) was used to ...
Beuter A - - 1987
Kinematic and electromyographic (EMG) parameters were analyzed on phase plane diagrams of human stepping motions performed over an obstacle of varying height. A videomotion analysis system was used to record the displacement of 5 reflective markers placed on the subject's lower limb joints. Surface bipolar electrodes were placed on the ...
Dimberg U - - 1987
The present study was designed to evaluate whether aversively conditioned responses to facial stimuli are detectable in all three components of the emotional response system, i.e. the expressive/behavioral, the physiological/autonomic and the cognitive/experienced component of emotion. Two groups of subjects were conditioned to angry or happy facial expression stimuli using ...
Sajiki N - - 1987
Using reaction time paradigm, the effect of repetitive passive motion (RPM) on the initiation of fast knee extension was analyzed in seven normal subjects and 10 patients with paraparesis. Before and after 5 min RPM of the responding lower extremity, i.e., alternate flexion and extension of the knee and the ...
Wastell D G - - 1987
Masseter EMG and bite force recordings were made from six subjects. Multiple regression analysis was performed and an equation produced relating EMG and bite force in SI units. Evidence is presented for a component of masseter EMG which can be related to the acceleration of bite force during onset of ...
Kossev A - - 1987
The monosynaptic electromyographic reflex (EMG) response to muscle stretching represents a synchronized discharge from the single motor units (MUs). The role of this synchronization, taking into account the effect of the subsequent voluntary activity, has been investigated by calculating the probabilities for the appearance of impulse from a single MU ...
Junginger J - - 1987
Vocal and forearm EMGs were recorded from 19 hallucinating and 22 nonhallucinating psychiatric inpatients. A microphone placed close to the lips was used to detect subvocal speech. The subjects' EMG and subvocal responses to pre-recorded statements were also assessed. Subjects who experienced hallucinations during assessment were asked to estimate the ...
Freude G - - 1987
This study investigates the electroencephalographic Bereitschaftspotential (Bp) during muscular-fatiguing and non-fatiguing rhythmical hand contractions at 20%, 50%, and 80% maximum voluntary contraction (MVC). A feedback arrangement was provided so that subjects were able to adjust the force as required. The results confirm that Bp depends on force level. An increase ...
Moritani T - - 1987
Twelve male subjects were tested to determine the relationship between motor unit (MU) activities and surface electromyogram (EMG) power spectral parameters with contractions increasing linearly from zero to 80% of maximal voluntary contraction (MVC). Intramuscular spike and surface EMG signals recorded simultaneously from biceps brachii were analyzed by means of ...
Bruce E N - - 1986
Spectral analysis was used to identify correlated sinusoidal frequency components in left and right side diaphragm electromyographic (EMG) recordings from human subjects during voluntary deep inspirations. In 31 of 33 subjects bilaterally correlated high-frequency oscillations were found in broad or narrow bands in the range of 60-84 and 16-40 Hz. ...
Nandedkar S D - - 1986
We have defined three new features of the electromyographic (EMG) interference pattern (IP): activity, upper centile amplitude (UCA), and number of small segments (NSS). These parameters were measured in simulated IPs constructed by adding together motor unit action potentials (MUAPs) recorded with a concentric needle EMG electrode. The activity increases ...
Aoki F - - 1986
The relationships between the integrated EMG (iEMG) of the first burst activity of the triceps brachii muscle and biomechanical variables such as acceleration, velocity and kinetic energy were examined for ballistic elbow extension in five healthy men. The duration of the first burst ceased within 100 msec in every subject. ...
Nandedkar S D - - 1986
We have developed three new features of the electromyographic interference pattern (IP), based on the turns and amplitude of the signal, to quantitate some of the features of the IP that are usually assessed subjectively by an electromyographer. The activity measures the fullness of the IP. The upper centile amplitude ...
Mongini F - - 1986
A computer-based system to assess mandibular movements and EMG masseter and temporal muscle activity during habitual mastication was applied to 12 healthy subjects and the chewing performance was tested with a standardized bolus of crisp bread. A Siemens Sirognatograph instrument was used to record mandibular movements while EMG signals were ...
Lee R G - - 1986
Mechanisms responsible for load compensation during fast voluntary movements were investigated in 20 normal subjects trained to carry out rapid wrist flexions against a standard load. When an unanticipated increase in load occurred, there was a compensatory increase in agonist EMG and decrease in antagonist EMG. Unanticipated decreases in load ...
Schemann M - - 1986
The effects of different nutrient meals and a noncaloric viscous cellulose meal (control) on the motor activity of the canine jejunum were studied. Contraction patterns were detected through six closely spaced, strain-gauge transducers and were analyzed by a computer. Luminal transit was assessed videofluoroscopically. Control meals moved rapidly (1.9 cm/s) ...
Moritani T - - 1986
Twelve male subjects were tested to determine the effects of motor unit (MU) recruitment and firing frequency on the surface electromyogram (EMG) frequency power spectra during sustained maximal voluntary contraction (MVC) and 50% MVC of the biceps brachii muscle. Both the intramuscular MU spikes and surface EMG were recorded simultaneously ...
Gill R C - - 1986
Extracellular electrical and contractile activities were recorded in vitro from strips of human colonic smooth muscle obtained at the time of surgery. Serosal electrical activity of longitudinally oriented strips from the taenia and intertaenial region was characterised by continuous oscillation at a frequency of 28 +/- 1/min. Contractions were marked ...
Winkel J - - 1986
As part of a larger ergonomic survey of seated work, the myoelectric activity of soleus and erector spinae was studied during typing and desk work while sitting on three different office chairs. Muscular performance was evaluated by two EMG methods: (1) the frequently used analysis of the amplitude probability distribution ...
Bräuer D - - 1986
The experiment aimed at elucidating electromyographic signs of fatigue of lumbar muscles. On two days, 4 subjects had to hold 4 different target forces to fatigue. Bipolar surface EMG's were derived at the L3 level. The time series structure of the EMG's was characterized by means of autoregressive models. The ...
Wetzel M C - - 1986
Human locomotion, as a behavioral system, is well suited for investigating the interplay of learning with innate biological mechanisms. The present work assembled, from previous findings, a test battery of operant conditioning to modify strong ongoing electromyographic (EMG) activity of the left tibialis anterior (TA), an ankle flexor muscle. An ...
Smith A - - 1985
Innocuous mechanical stimuli were applied to eight sites on the tongue dorsum and palate while subjects used feedback to maintain a constant isometric biting force. Reflex responses of the jaw-closing system were measured as changes in force and in EMGs recorded from right and left masseter muscles. Stimulation at each ...
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