655 resultados para electromyography
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O trabalho teve por objetivos estudar a condução nervosa motora e a transmissão neuromuscular e eletromiografia de repouso em gatos normais (grupo I), submetidos a hiperparatireoidismo secundário nutricional (grupo II). Para estudo normativo (grupo I), foram utilizados 10 gatos, aparentemente saudáveis, sem raça definida, sendo seis machos e quatro fêmeas, com idades entre 4 e 5 meses e peso médio de 1,67kg. No grupo II, empregaram-se 10 gatos, sem raça definida, sendo cinco machos e cinco fêmeas, com idade aproximada inicial entre 2 e 3 meses e peso inicial médio de 820 gramas. Após um período de adaptação de 10 dias, foram alimentados por 60 dias com coração bovino moído e cru, visando a indução de hiperparatireoidismo secundário nutricional. Foi possível concluir que latência, amplitude e velocidade de condução nervosa motora e os achados eletromiográficos das atividades insercional e espontânea de gatos com hiperparatireoisdismo secundário nutricional, apresentaram um padrão similar aos de gatos normais da mesma idade. Para estimulações repetitivas a 3Hz, observou-se tendência global a decremento dos potenciais de ação musculares compostos e a 10 Hz houve tendência de incremento ou decremento; entretanto, tais variações apresentaram-se dentro dos limites de normalidade.
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In this study we investigated the hypothesis that the simple set of rules used to explain the modulation of muscle activities during single-joint movements could also be applied for reversal movements of the shoulder and elbow joints. The muscle torques of both joints were characterized by a triphasic impulse. The first impulse of each joint accelerated the limb to the target and was generated by an initial burst of the muscles activated first (primary mover). The second impulse decelerated the limb to the target, reversed movement direction and accelerated the limb back to the initial position, and was generated by an initial burst of the muscles activated second (secondary movers). A third impulse, in each joint, decelerated the limb to the initial position due to the generation of a second burst of the primary movers. The first burst of the primary mover decreased abruptly, and the latency between the activation of the primary and secondary movers varied in proportion with target distances for the elbow, but not for the shoulder muscles. All impulses and bursts increased with target distances and were well coupled. Therefore, as predicted, the bursts of muscle activities were modulated to generate the appropriate level of muscle torque. (C) 2005 Elsevier Ltd. All rights reserved.
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1. The present study compared the duration of the electromyographic silent period (SP) of the masseter muscles elicited by chin-tapping in normal asymptomatic adults (N = 39) and in a group with symptoms of temporomandibular joint dysfunction (TMJD) (N = 31).2. EMG activity was recorded from right (RM) and left (LM) masseter muscles using bipolar surface electrodes coupled to a DISA 1500 EMG-System. During maximal clenching, ten taps were applied downwards to the chin with a reflex hammer.3. The mean SP durations obtained for the normal group were 25.45 +/- 4.20 ms (RM) and 25.33 +/- 4.18 ms (LM), whereas the TMJD group presented significantly greater values (P < 0.01, Student t-test) of 41.89 +/- 12.94 ms (RM) and 42.40 +/- 12.99 ms (LM). The upper limits of normality calculated for RM and LM were 32.36 ms and 31.21 ms, respectively. Eighty-four percent of patients with TMJD showed SP durations above these limits.4. The results indicate that the measurement of masseteric SP duration may be used as an objective diagnostic method of TMJ disorders, provided that borderline values are interpreted with caution along with clinical impressions.
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CAUDA equina syndrome (CES) has long been recognized as a rare complication of spinal anesthesia.(1) CES has been described after administration of spinal anesthetics with lidocaine(2) and bupivacaine.(3) In 1991,(4) CES was reported after continuous spinal anesthesia with 1% tetracaine. In 1980, at our university hospital, six adult female patients underwent perineal gynecologic surgery using a spinal anesthetic of 2 ml tetracaine, 1.2%, in 10% glucose. The concentration of the injected tetracaine was unknown by the anesthetists. In all cases, lumbar puncture was performed at the L3-L4 interspace with a disposable spinal needle while the patients were in the sitting position. CES was first diagnosed 72 h or later postoperatively; previous diagnosis was not possible because patients had an indwelling urethral catheter. The diagnosis of CES was confirmed in all patients. During the past year, after institutional approval and informed consent, clinical, magnetic resonance imaging, electromyographic examinations, and conduction studies were performed in three of the above patients. Examinations were not possible on the other three patients because one had recently died, another could not be located, and the third refused to participate. T1 and T2 magnetic resonance image readings were obtained with Gadolinium contrast from a 0.5 Tesla General Electric apparatus (General Electric, Tokyo, Japan). Bilateral sensory and motor conduction studies of the sciatic nerve branches were obtained using a two-channel Nihon-Kohden Neuropack 2 (Nihom-Kohden Corporation, Tokyo, Japan). Electromyography was performed in accordance with conventional techniques.(5,6)
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Queiroz BC, Cagliari MF, Amorim CF, Sacco IC. Muscle activation during four Pilates core stability exercises in quadruped position. Arch Phys Med Rehabil 2010;91: 86-92.Objective: To compare the activity of stabilizing trunk and hip muscles in 4 variations of Pilates stabilizing exercises in the quadruped position.Design: Repeated-measures descriptive study.Setting: A biomechanics laboratory at a university school of medicine.Participants: Healthy subjects (N=19; mean age +/- SD, 31 +/- 5y; mean weight +/- SD, 60 +/- 11 kg; mean height +/- SD, 166 +/- 9cm) experienced in Pilates routines.Interventions: Surface electromyographic signals of iliocostalis, multifidus, gluteus maximus, rectus abdominis, and external and internal oblique muscles were recorded in 4 knee stretch exercises: retroverted pelvis with flexed trunk; anteverted pelvis with extended trunk; neutral pelvis with inclined trunk; and neutral pelvis with trunk parallel to the ground.Main Outcome Measures: Root mean square values of each muscle and exercise in both phases of hip extension and flexion, normalized by the maximal voluntary isometric contraction.Results: The retroverted pelvis with flexed trunk position led to significantly increased external oblique and gluteus maximus muscle activation. The anteverted pelvis with trunk extension significantly increased multifidus muscle activity. The neutral pelvis position led to significantly lower activity of all muscles. Rectus abdominis muscle activation to maintain body posture was similar in all exercises and was not influenced by position of the pelvis and trunk.Conclusions: Variations in the pelvic and trunk positions in the knee stretch exercises change the activation pattern of the multifidus, gluteus maximus, rectus abdominis, and oblique muscles. The lower level of activation of the rectus abdominis muscle suggests that pelvic stability is maintained in the 4 exercise positions.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In 21 normal adult male subjects, the muscular activity of the levator scapulae and rhomboideus major muscles was studied electromyographically during the movements of the shoulder and arm. Two single coaxial needle electrodes were used for registering the action potentials. Concerning shoulder movement, it was shown that the levator scapulae was active in elevation and rhomboideus major was active in retraction. Both muscles were inactive during protrusion, in most events. Concerning free movements of the arm, both muscles were active in abduction, elevation, adduction, flexion and circumduction, but inactive in extension. During the same movements, performed with a load, we observed greater intensity in the activity of these muscles in comparison to their activity during free movements.
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The authors studied the trapezius (middle portion) and rhomboideus major muscles in movements of flexion, extension, inclination and rotation of the trunk. The electromyographic records demonstrate that such muscles show activity only at the ending of flexion, being inactive in the other movements.
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An electromyographic study of the musculus interosseus dorsalis was performed on the right hand of 25 young adult male right-handed volunteers. The electrodes, simple coaxial needles, were implanted one at the ulnar head and the other at the radial head of the muscle. The muscles were analyzed during free movements of the index and against resistance. The same movements were done in four different positions of the fore-arm and hand, without variation in the results for each one of the movements. There was no significant difference between the activities of the ulnar head and radial head. During freely performed movements, muscle activity was recorded only during abduction. During movements against resistance, muscle activity was completely nil only during adduction; during the remaining movements, however, moderate (2+), strong (3+) and very strong activity (4+) was recorded.
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The participation of the levator scapulae and rhomboideus major muscles in some movements of the upper limb was analysed in 21 young adult male volunteers. A 2 channel TECA TE4 electromyograph connected with single coaxial needle electrodes was used. In abduction, elevation, adduction, flexion and circumduction participation of both muscles in free movements of the upper limb was found. In extension, however, these muscles were inactive. In the same movements analysed with load, a major intensity of action of these muscles was registered as compared with those obtained in free movements.
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The authors studied the trapezius (pars media) and rhomboideus major muscles during deep inspiration and expiration. The electromyographic records demonstrated that these muscles showed no activity in either phase of breathing.
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The authors studied the trapezius (pars media) and rhomboideus major muscles in movements of flexion, extension, inclination and rotation of the head. The electromyographic records demonstrated that referred muscles are inactive in these different movements.
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The participation of the trapezius (middle portion) and rhomboideus major muscles submitted to an isometric tension (holding downward dumbells of 11, 15 and 19 kg) was analysed in 40 young adult male vounteers. A 2 channel TECA TE4 electromyograph connected with single coaxial needle electrodes was used. In the initial phase of the test, holding downward, generally the trapezius and rhomboideus major muscles showed activity and no activity, respectively. In the cases where activity was present during the downward positions it was reduced gradually until complete rest.
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The participation of the trapezius (pars media) and rhomboideus major muscles in free movements of abduction, adduction, flexion, extension and hyperextension of the arm was studied electromyographically. These muscles were active and synergic in all analysed movements, both acting with intensity that ranged from moderate to very marked.