Search Results
Results 401 - 450 of 681
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Wolf S L - - 1997
Additional studies to determine intratester reliability of electrokinesiologic (EK) measures related to trunk movement and low back muscle activity are needed. EMG activity and EK records of repetitive movements at both natural and maximal speeds were computer sampled and quantified among 22 nonimpaired subjects. Significant differences were observed between group ...
van Bolhuis B M BM Department of Medical Physics and Biophysics, University of Nijmegen, The Netherlands. - - 1997
Simultaneous recordings of action potentials (APs) of multiple single motor units (MUs) were obtained in brachialis and biceps (caput breve) muscles during sinusoidally modulated isometric contractions of elbow flexor muscles and during sinusoidal flexion/extension movements in the elbow against a preload in the extension direction. The results show that MUs ...
Taylor A D - - 1997
The aim of this investigation was to re-evaluate the relationship between electromyography and work intensity during incremental work in light of highly discrepant literature. Trained male subjects participated in the study (n = 14). Each subject completed a VO2max test on a cycle ergometer. Tests started at a power output ...
Bazzotti L - - 1997
On a population of 52 subjects surface electromyographic recordings were performed of 13.5 sec. of duration before and after ULF (Ultra Low Frequency)-TENS relaxing procedure, while they were holding their mandible at rest. For each recording the average of tension (IEMG) and the median of frequency was calculated. To compute ...
Yeh E R - - 1997
In this study we sought to determine the role of the paraventricular nucleus of the hypothalamus (PVN) in modulating respiratory output. Experiments were performed in urethane anesthetized, vagotomized and mechanically ventilated Wistar rats. Electromyographic activity of the diaphragm (D[EMG]) was recorded and used to define the respiratory effects of PVN ...
Chen J J - - 1997
Analyzing motor unit (MU) activity is essential for studying the neurological dysfunction of upper motor neuron disorders (UMND). This study employs multichannel surface electromyographic (EMG) signals, as recorded from the upper arm during elbow flexion and extension, to analyze the temporal changes and spatial distribution of the dominant firing rate. ...
Finsterer J - - 1997
OBJECTIVES: To investigate the accuracy of the turn/amplitude-analysis (TAA) in the detection of subclinical myogenic lesions, for which Duchenne (DMD) carriers were taken as a model. MATERIALS AND METHODS: Conventional EMG (MUAP analysis) and the TAA with/without force monitoring were applied to the right brachial biceps and femoral rectus muscles ...
Roeleveld K - - 1997
Surface EMG (SEMG) is little used for diagnostic purposes in clinical neurophysiology, mainly because it provides little direct information on individual motor units (MUs). One of the techniques to estimate the MU size is intra-muscular Macro EMG. The present study compares SEMG with Macro EMG. Fifty-eight channel SEMG was recorded ...
Hidaka O - - 1997
To examine the relationships between masticatory force, electromyogram (EMG) of masticatory muscles, and jaw movement pattern, we quantitatively evaluated the effects of changing hardness of a chewing substance on these three variables. Cortically induced rhythmic jaw movements of a crescent-shaped pattern were induced by electrical stimulation of the cerebral cortical ...
McAuley J H JH HMBU, Institute of Neurology, London, - - 1997
The output from the central nervous system to muscles may be rhythmic in nature. Previous recordings investigating peripheral manifestations of such rhythmic activity are conflicting. This study attempts to resolve these conflicts by employing a novel arrangement to measure and correlate rhythms in tremor, electromyographic (EMG) activity and muscle vibration ...
Hodges P W PW Department of Physiotherapy, The University of Queensland, - - 1997
Because the structure of the spine is inherently unstable, muscle activation is essential for the maintenance of trunk posture and intervertebral control when the limbs are moved. To investigate how the central nervous system deals with this situation the temporal components of the response of the muscles of the trunk ...
Kopeć J - - 1997
In this report a new technique of recording, employed for the first time in routine clinical electromyography (EMG) is described. Conventional analysis is extended to the order of recruitment pattern, and relates the new electrophysiological features to current data about anatomical reorganization of all active motor units (MUs) and their ...
Hägg G M - - 1997
Electromyographic activity (EMG) from m. flexor carpi radialis (FCR) and m. extensor carpi radialis longus (ECRL) of the right forearm was recorded together with wrist angles in the flexion/extension and radial/ulnar plane in 20 healthy automobile assembly line workers during work. Eleven of these were randomly recruited from assembly stations ...
Morlock M M - - 1997
This study was designed to investigate the relationship between trunk muscle fatigue and associated changes in the electromyographic (EMG) signals during a dynamic iso-inertial test. Eleven subjects performed dynamic trunk flexion/extension movements against 40% maximum voluntary contraction (MVC) torque until exhaustion in a tri-axial trunk dynamometer. EMG parameters in the ...
Potvin J R - - 1997
Fifteen male subjects performed a repetitive elbow flexion/extension task with a 7-kg mass until exhaustion. Average joint angle, angular velocity, and biceps brachii surface electromyographic (EMG) amplitude (aEMG) and mean power frequency (MPF) were calculated with each consecutive 250-ms segment of data during the entire trial. Data were separated into ...
Stief C G - - 1997
OBJECTIVE: The aim of our study was to investigate analogous and digital recording of corpus cavernosum EMGs (CC-EMGs) in normal men according to criteria that were recently agreed upon in an international consensus workshop. METHODS: CC-EMGs were analogously and digitally registered from 37 normal subjects. Power spectra in the frequency ...
Oda S - - 1996
The purpose of this study was to compare movement-related cortical potentials (MRCPs) associated with different levels of isometric contractions by elbow flexors. Eight healthy, right-handed male subjects participated in this study and performed different levels (10 and 50% of maximal voluntary contraction) of isometric contractions by the right elbow flexors. ...
Martin B J - - 1996
This study examines the relationship between forearm EMGs and keyboard reaction forces in 10 people during keyboard tasks performed at a comfortable speed. A linear fit of EMG force data for each person and finger was calculated during static fingertip loading. An average r2 of .71 was observed for forces ...
Lee S K - - 1996
OBJECTIVES: The sphincter of Oddi (SO) manometry via the transpapillary route is performed usually for a period of several minutes. To investigate whether there is a considerable variation in the manometric measurements of SO over a longer period of time, we have performed long-term manometry of SO via the transpapillary ...
Itakura N - - 1996
We tried to discriminate different forearm's motions by surface EMG signals using neural network. In order to get a higher discrimination rate, the positions of electrodes were improved. We also tried to discriminate similar motions in order to clarify the limitation of the discrimination by surface EMG signals. Two experiments ...
Gottlieb G L - - 1996
1. Eight subjects performed three series of pointing tasks with the unconstrained arm. Series one and two required subjects to move between two fixed targets as quickly as possible with different weights attached to the wrist. By specifying initial and final positions of the finger tip, the first series was ...
Søgaard K - - 1996
Motor unit (MU) recruitment patterns were studied in 6 female subjects during dynamic contractions at relative workloads corresponding to 10% maximum voluntary contraction. The contractions consisted of a 20 degree elbow flexion (concentric contraction) and extension (eccentric contraction) and MU action potential trains were recorded from the brachial biceps muscle. ...
Li L - - 1996
Electromyographic (EMG) responses of the cervicoauricular muscles (CAM) to free-field sounds were recorded in two groups of rats whose brainstems were dissected transversely either at a pretectal or transtectal level. After the rat recovered from anesthesia, wide-band noise pulses were presented and speaker positions were varied systematically in azimuth. Sound ...
Bahuguna R D - - 1996
A prism fingerprint sensor is described that uses a holographic grating glued to a right-angled prism. A light source normally illuminates the hypotenuse side of the prism with the finger pressed against the grating. The ridges and valleys of the finger are sensed on the basis of the principle of ...
Sanders D B - - 1996
The electromyographic interference pattern (EMG-IP) contains information about the number, firing rate, and recruitment characteristics of motor units, and information regarding the waveforms of the recruited motor units. Muscle and nerve diseases produce characteristic changes in the IP that can be distinguished by IP analysis. This analysis complements analysis of ...
Gerard M J - - 1996
An experiment was conducted to investigate the effect of key stiffness on the development of fatigue, keyboard reaction forces, and muscle electromyography (EMG) responses. Six subjects typed continuously for 2 hours on each of two keyboards (0.28 N or 0.83 N resistance keys, presented in random order). Keyboard reaction force ...
Oliver C W - - 1996
OBJECTIVE: To establish the reproducibility of surface recordings of electromyograms from lumbar erector spinae muscles. DESIGN: Repeated measurements in 10 male volunteers under controlled conditions. METHODS: While isometric load was held constant at (2/3) and (1/3) of maximum voluntary contraction, surface electromyograms were recorded from the 4th/5th lumbar interspace on ...
Kang W J - - 1996
Identification of motions of the neck and shoulders using the electromyographic (EMG) signal was investigated in this study. Three discrimination methods, the Euclidean distance measure (EDM), the weighted distance measure (WDM) and the modified maximum likelihood method (MMLM), were used to compare the conventional autoregressive (AR) and cepstral coefficients with ...
Svensson P - - 1996
The influence of peripheral afferent activity on human jaw motor function was examined in this study. Painful argon laser stimuli were applied to the upper lip in 10 subjects during rhythmical jaw movements and the effects on the jaw-closer electromyogram (EMG) and jaw movements were studied. The duration of the ...
Ottenhoff F A - - 1996
In six human subjects, electromyograms (EMGs) of the masseter and temporal muscles were recorded bilaterally during experiments in which the subjects made rhythmic open-close movements. The closing phase was counteracted by a variable external force on the mandible. Variables of the force (amplitude, time integral and work) and variables of ...
Nava S - - 1996
The fatigue threshold of the human diaphragm, index of its endurance and fatigability, corresponds, during spontaneous breathing, to a tension-time index (TTdi = Pdi/Pdimax x T1/Ttot (i.e., the inspiratory time over the total breath duration) of 0.15 to 0.18. We studied three quadriplegic patients with diaphragm pacing in order to ...
Mansour S - - 1996
The objective is to analyse internal and external recordings of uterine EMG in order to reveal common features and to assess the relationship between electrical activity and intra-uterine pressure modification. Three monkeys participated in the study, one as a reference and the others for data. EMGs are recorded simultaneously, internally ...
Naraki N - - 1996
The purpose of the present study is to evaluate the static work load as a model work in Submersible Decompression Chamber (SDC) during a deep sea saturation dive with helium-oxygen gas mixture. Heart rate (HR) and electromyogram (EMG) power spectrum changes were studied during a 7-minute static work, half-rising posture ...
Niebuhr B R - - 1996
The purpose was to determine if the surface electromyogram (EMG) would allow detection of submaximal grip exertions of variable effort. Fifteen healthy subjects were instructed on different trials to give maximal 100% efforts, fixed 50% submaximal efforts, or submaximal efforts of variable amount (30, 40, 50 or 70%) with the ...
Chan R C - - 1996
BACKGROUND: In the previous studies, the results from power spectrum frequency changes at different sustained forces have been quite conflicting. This was the result of enormous changing in firing rate and motor units recruited; these were deciding factors of electromyographic power spectrum. The aim of this study was to investigate ...
Attebrant M - - 1995
The present study compared three procedures for normalization of upper trapezius surface electromyographic (EMG) amplitudes: (a) a ramp procedure (providing data in per cent of maximal voluntary contraction, MVC); (b) a constant force procedure based on two reference contractions (two-force procedure) (%MVC) and (c) a procedure expressing muscle activation in ...
Kang W J - - 1995
A new technique for classifying patterns of movement via electromyographic (EMG) signals is presented. Two methods (conventional autoregressive (AR) coefficients and cepstral coefficients) for extracting features from EMG signals and three classification algorithms (Euclidean Distance Measure (EDM), Weighted Distance Measure (WDM), and Maximum Likelihood Method (MLM)) for discriminating signals representative ...
Nakajima I - - 1995
Frequency changes of the masseter muscle EMG were examined in eight healthy subjects during the reaction time for unilateral jaw biting paradigm. The subjects were instructed to bite on a small piece of wood after the second of two visual signals two seconds apart. In five subjects, the EMG frequencies ...
Merletti R - - 1995
Myoelectric manifestations of muscle fatigue have been described by monitoring the first-order moment (mean frequency) of the power spectral density function during voluntary or electrically elicited sustained contractions. Higher order central moments provide additional information about the width, skewness, and kurtosis of the spectrum and its shape changes, thereby providing ...
Yue G - - 1995
Motor unit synchronization was estimated from the surface electromyograms (EMG) of the first dorsal interosseus muscle of human volunteers by a simplified surface-EMG technique (Milner-Brown et al. 1973, 1975). Single motor units were identified from intramuscular recordings and were used to obtain a spike-triggered average of the surface-EMG. The discharge ...
Baker S N - - 1995
Studies on the motor system commonly use averages of rectified electromyogram (EMG) to measure muscular response. The assumption is usually made that this is a linear measure of response magnitude. It is shown here using a theoretical and experimental model that averages of rectified EMG can lead to non-linearities, which ...
Fourment A - - 1995
1. Two monkeys (Macaca fascicularis) making high-level but submaximal isometric flexions of the elbow were investigated for the output effect of motor cortical cells on the electromyogram (EMG) activity of two main elbow flexors using the method of spike-triggered averaging of rectified EMGs (STAs). 2. Monkeys were trained to perform ...
Medved V - - 1995
We have studied skilled human locomotions in sports gymnastics by measurement and analysis of ground reaction force and myoelectric signals. Assuming the quality of performance to be a skill level criterion acquired signals were mathematically analyzed via basic signal processing and cross-correlation methods. The study of backward somersault yielded quantitative ...
Gitter J A - - 1995
Evaluation of motor unit recruitment is an important component of the clinical EMG exam. Typically this is assessed qualitatively using auditory features and estimates of the visual complexity of the EMG waveform. Recent advances in nonlinear dynamics have led to the development of the concept of fractals which can be ...
Le Menn M - - 1995
A special preamplifying system was designed to record electrophysiological signals on fighter aircrew in flight. The system is composed of two elements worn by the pilot in a specially designed jacket. The first element is a preamplifying device for ECG or EMG signals, which includes one or two accelerometer channels, ...
Roark R M - - 1995
Digital recordings of thyroarytenoid (TA) myoelectric activity (via percutaneous hooked-wire electrodes) were obtained for 10 normal control subjects and 10 subjects with spasmodic dysphonia during performance of five tasks of varying complexity: quiet breathing, Valsalva maneuver, whispered /i/, voiced /i/, and "beep beep went the heap." Time-frequency power spectral density ...
Guimaraes A C - - 1995
The relationship between force and electromyographic (EMG) signals of the cat soleus muscle was obtained for three animals during locomotion at five different speeds (154 steps), using implanted EMG electrodes and a force transducer. Experimentally obtained force-IEMG (= integrated EMG) relationships were compared with theoretically predicted instantaneous activation levels calculated ...
Webber C L CL - - 1995
The summed electrical discharges generated by a contracting skeletal muscle constitute a dynamic system conveying electromyographic (EMG) information indicative of muscle physiological status. "Steady states" of activity can be achieved with light loads, but with heavy loads the dynamic system experiences continuous status transitions that culminate in task failure. The ...
Devanne H - - 1995
The jaw movement kinematics in relation to the EMG activity of two antagonistic jaw muscles (the masseter and the digastricus pars anterior) were examined in healthy subjects and patients with Friedreich's disease. Dysarthria and ataxia are the main characteristics of this disease. Jaw movement was monitored with a magnetometer system, ...
Arena J G - - 1995
This is a re-analysis of data from a previous study which examined the temporal stability of three psychophysiological responses [frontal electromyographic activity (EMG), hand surface temperature, and heart rate]. Each response was recorded on 64 subjects over four sessions, each of which consisted of a 20-min, adaptation period, a baseline ...
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