Electromyography and clinical neurophysiology最新文献

The purpose of this investigation was to examine the influence of patellofemoral pain (PFP) on the amplitude of the mechanomyographic (MMG) and electromyographic (EMG) signals from the vastus lateralis and vastus medialis muscles of the quadriceps femoris. Nine females reporting current signs and symptoms of PFP and 8 healthy females service as the control (CTL) group volunteered to participate in this study. Participants completed maximal and submaximal (25, 50, 75% MVC) isometric muscle actions of the quadriceps femoris at a leg flexion angle of 45 degrees below the horizontal plane of the lever arm. The involved limb for the PFP group and the dominant limb for the CTL group were selected for testing and all submaximal force levels were randomized. There was no (p > 0.05) group difference in EMG amplitude response for any muscle at any % MVC level. For the MMG amplitude, however, there was a main effect (p < 0.05) for group where the control group demonstrated greater MMG amplitude for each muscle. These findings suggest that the presence of PFP influenced mechanical aspect of muscle function as measured by MMG, but not the electrical properties (EMG). MMG may provide unique insight into the intrinsic effects on muscle function due to PFP.

Objective: In view of paucity of studies on P3 in encephalitis, we report clinical, MRI and P3 changes in encephalitis patients.

Design: The diagnosis of encephalitis was based on clinical, MRI, ELISA and/or PCR and categorized into Japanese encephalitis (JE), dengue, herpes (HSE) and nonspecific group. Cognitive functions were evaluated 1 month after the illness when patient was able to cooperate for Mini Mental State examination (MMSE). P3 was carried out by odd ball auditory paradigm recording from Cz, Fz and Pz referred to linked mastoids.

Results: 30 encephalitis patients including 16 JE, 2 HSE and 12 nonspecific whose median age was 24 (13-53) years were prospectively evaluated. P3 was studied after a median duration of 3 months. MMSE was abnormal in 19 patients. CzP3 was abnormal in 6; 5 of whom had abnormal MMSE. MRI was abnormal in 18 showing thalamic lesion in 13, basal ganglia in 3 and cortical in 7 patients. MMSE was abnormal in all the patients with HSE, 81% with JE and 33% with nonspecific encephalitis. P3 was more frequently abnormal in patients with abnormal MMSE and MRI.

Conclusion: Cognitive impairment is common in HSE and JE; abnormal MMSE and MRI are associated with P3 abnormality.

Objective: The purpose of this study was to investigate correlations between masseter muscle activity and cephalometric measures in Angle's class III dental malocclusion under the clinical rest position.

Methods: Eight volunteers, both sex, age 7-12, were submitted to an electromyographic analysis of the masseter muscle, subdivided in the upper, medium and lower regions, and to a cephalometric analysis of 15 angle and linear measurements. After normalization, the data was subjected to a statistical, non-parametric Spearman correlation test, by means of the SPSS 12.0 program.

Results: Statistically significant correlations were observed between the clinical rest condition before and after the execution of exercises (a serie of mandibular movements), and the cephalometric measurements angle SN GoGn, angle SNA, angle SNB, angle SND, upper incisive. NA angle, upper incisive-NA distance, lower incisive. NB angle, lower incisive-NB distance and angle IMPA, and the different regions of the masseter muscle.

Conclusions: The significant statistical correlation found between the cephalometric analysis and the function of the masseter muscle indicate a strong influence of the musculature under a clinical rest condition over the cranial-facial development in the Angle's class III dental malocclusion. There is a selective activity of the different regions of the masseter muscle under the clinical rest condition in the Angle's class III dental malocclusion. There is a demand for research to complement these findings in other classes of dental malocclusion.

Today, many office workers frequently adopt a relaxed or slumped sitting posture for many hours, and often people tend to spend their leisure time reclining against the backrest of a chair while sitting for a long time, as when watching television. While sitting, the pelvis rotates backwardly, and lumbar lordosis is flattened. Simultaneously, the load on the intervertebral discs and spine increases. Sitting in a slumped position is known to increase disc pressure even more, and to aggravate chronic low back pain (CLBP). Therefore, it is very important to teach workers and often people about the correct sitting posture. In addition, it has been recognized that co-contraction of the deep spine-stabilizing muscles enhances lumbar segmental stability and the sacro-iliac joint. However, little is known about the influence of co-contraction of the trunk deep muscles on spinal curvature during sitting reclining against the backrest of a chair. The purpose of this study was to compare the EMG (electromyographic) activity of the trunk muscles during slump sitting with that during co-contraction and to investigate how this cocontraction influences spinal curvature. Ten healthy male volunteers (20.8 +/- 0.8 years old) without CLBP participated in the study. Bipolar surface electrodes were attached to the rectus abdominis, the obliquus externus abdominis, the obliquus internus abdominis, the lower back extensor muscles (L3) and the multifidus on the right side. The EMG signals were continuously recorded during slump sitting and co-contraction of the trunk muscles, reclining against the backrest of chair. They were amplified, band-pass filtered, digitized and stored by a data acquisition system. The average muscle activity values over the five-second sample for each sitting posture were normalized to maximal voluntary contractions (%MVC). While the subjects performed both sitting postures, the curvature of the spine was measured using a new skin-surface and hand-held device, the "Spinal Mouse". More significant activities of the trunk muscles, with the exception of the rectus abdominis and the lower back extensor muscles (L3), were observed during co-contraction of the trunk muscles than during slump sitting. The co-contraction of the trunk muscles resulted in significantly less lumbar curvature and more sacral angle than during slump sitting. The thoracic curvature showed no significant change during either sitting posture. The results of this study indicated that co-contraction of the trunk muscles during sitting reclining against the backrest of a chair could bring about the correct lumbar curvature, effectively stabilize the lumbopelvic region, and decrease focal stress on passive structures.

Purpose: Diabetic polyneuropathy (PNP) is an important risk factor for foot ulcers. Diabetic dermopathy is more frequent in patients with diabetic neuropathy. We compared clinical and electrophysiological characteristics of PNP localizations/recurrences of foot ulcers, and diabetic dermopathy (DD) between sexes.

Methods: Eighty-eight diabetic patients (44 men, 44 women) had an evaluation regarding detailed history of their diseases, lesion-related data, and clinical examination. Nerve conduction velocities (NCV), compound motor action potentials (CMAP), distal latencies (DL), and sensory nerve action potentials were assessed from the right and left peroneal, right median/ulnar nerves.

Results: The presence of DD was more common in men (p < 0.001). The mean NCV of ulnar nerves was slower (p < 0.001); mean CMAP values were lower (p = 0.006); and mean DL was longer in men with compared to women (p = 0.003). Although EMG features of peroneal nerves showed no significant difference, diabetic men had more common and severe peroneal nerve involvement (p = 0.004). Carpal tunnel syndrome was more common in women, though not significant. Patients with right-sided ulcers had lower CMAP amplitudes on the right peroneal nerves in regard to left peroneal nerves (p = 0.009).

Conclusions: Our findings suggest that ulnar nerves are more commonly involved in men, with lower CMAP slower NCV values, and longer DL values.

Proceed to a comparative analysis of the electromyographic (EMG) activity of the muscles rectus femoris, vastus medialis and vastus lateralis, and to assess muscle strength and fatigue after maximal isometric contraction during knee extension. Eighteen patients with post-polio syndrome, age and weight matched, were utilized in this study. The signal acquisition system utilized consisted of three pairs of surface electrodes positioned on the motor point of the analyzed muscles. It was possible to observe with the results of this study a decreased endurance on initial muscle contraction and during contraction after 15 minutes of the initial maximal voluntary contraction, along with a muscle fatigue that was assessed through linear regression executed with Pearson's test. There were significant differences among the comparative analysis of EMG activity of the muscles rectus femoris, vastus medialis and vastus lateralis after maximal isometric contraction during knee extension. Initial muscle contraction and contraction after a 15 minute-rest from initial contraction decreased considerably, indicating a decreased endurance on muscle contraction, concluding that a lower limb muscle fatigue was present on the analyzed PPS patients.

The purpose of this study was to investigate the effect of finger movement on ankle control for gait initiation in patients with Parkinson's disease (PD patients). The subjects were 13 PD patients and 6 age-matched healthy adults. The subjects moved fingers before or after gait initiation, or initiated gait without finger movement. Ankle joint movement in the stance leg was recorded to estimate the duration of ankle dorsiflexion (DIF duration), which reflects the degree of disturbance in ankle control for gait initiation in PD patients. In the PD patients with prolonged D/F duration, finger movement that preceded gait initiation shortened the D/F duration, but in the PD patients without prolonged D/F duration and in healthy subjects, the effect was not found. Accordingly, finger movement that precedes gait initiation improves ankle control for gait initiation in PD patients who suffer disturbance in ankle control for gait initiation.

It was purposed the use of electromyography (EMG) to evaluate the activation of the agonists and antagonists muscles of spastic patients, to test the viability in the development of an instrument that given quantitative data of the patient spasticity. 30 hemiplegic and 15 normal volunteers had been submitted to the EMG of flexor and extensor carpi ulnaris muscles during the flexion and extension movements of the wrist. The individuals with less severe spasticity (mAS (modified Ashworth Scale) ringing 0 to 3 degree), had presented deficit in the activation of the flexor muscles in plegic side in relation to the non plegic side and that the individuals seriously compromised by the spasticity (mAS = 4 degree) present deficit of reciprocal inhibition. One evidenced is that the non plegic member does not present a similar neuro-motor comportment when compared to the normal member. The surface electromyography is a practical clinical instrument to evaluate the patient with spasticity and the hemiplegic patient needs to be evaluated on both sides (deficient and no deficient) because the no compromised side do not show a normality standard.

Background: Lipomas are common benign soft tissue tumours which tend to be indolent and risk free. Lipomas rarely spread in the deep soft tissue causing posterior interosseous nerve (PIN) neuropathy.

Methods (case description): We present two patients with multiple lipomatosis of the arms and PIN paralysis, with a brief review of the cases reported in literature.

Results and conclusion: We emphasize the role of electromyographic study as unique methodical capable to reveal an early radial nerve damage, permitting an optimal post-surgical nerve function recovering.

The proposal of this study was to analyze the behavior of electromyographic activity of the Rectus Femoris, Vastus Lateralis and Vastus Medialis muscles during Maximum Isometric Voluntary Contraction (MIVC) performed before (MIVC-1) and after (MIVC-2) the series of repeated effort (four series of 12 repetitions) of the movement of extending the knee performed on an extending table with 80% of maximum load (1RM) during 15 seconds each MIVC. The participants were 10 soccer players (average age of 17.7 +/- 0.67, average corporal mass of 67.07 +/- 6.06 kg and average height of 174.6 +/- 4.98 cm). Surface electrodes (disposable) were used. The frequency established was 1024 Hz (Low/High pass at 600/10 Hz). The statistical treatment employed analysis of variance (ANOVA) for repeated measurements followed by the HSD post hoc test of Tukey. The level of significance adopted for all analyses was p < 0.05. For the Rectus Femoris muscle the value expressed in RMS referring to MIVC-1 was 346.97 +/- 63.93 and MIVC-2 was 287.58 +/- 61.03 (p = 0.06) corresponding to 82.88% of MIVC-1. Regarding the Vastus Lateralis muscle the value in MIVC-1 was 385.50 +/- 120.23 and in MIVC-2 it was 316.87 +/- 67.85 (p = 0.04) corresponding to 82.19% of MIVC-1. For the Vastus Medialis muscle MIVC-1 value was 430.88 +/- 84.23 and MIVC-2 was 396.32 +/- 70.40 (p = 0.03) corresponding to 91.97% of MIVC-1. Results demonstrated that the muscles presented action potencies during the actions performed, being greater in MIVC-1. The Rectus Femoris muscle presented electromyographic signals of lesser amplitude than the Vastus Lateralis and Vastus Medialis muscles. The Vastus Medialis muscle presented a greater percentage value between MIVC-1 and MIVC-2. The Rectus Femoris muscle was the first to present signs of fatigue.