Electromyography and clinical neurophysiology最新文献

Although bicycle ergometer exercise and walking are recommended as aerobic exercise for patients with lumbago, little research has been done to examine the muscular activities and circulatory dynamics during these exercises. In this study, we aimed at obtaining basic information on aerobic exercises effective for patients with lumbago by investigating the activities and circulatory dynamics of their lumbar muscles during bicycle ergometer exercise and walking. As subjects, we selected 10 healthy adults (23.7 +/- 3.4 years old) with no anamnestic history of lumbago. The measurement conditions were 4 types of exercise: walking (4.0 km/h); 25W, 50W and 75W bicycle ergometer exercises. The activities of the lumbar muscles during the exercises were measured by a surface electromyograph, and percent of MVC was calculated from the maximal voluntary contraction (MVC). With regard to the circulatory dynamics of the lumbar muscles, we measured oxygenated hemoglobin (Oxy-Hb) and deoxygenated hemoglobin (Deoxy-Hb) before and after the exercises with near infrared spectroscopy (NIRS). The change rates during the exercises were calculated based on the values before the exercises. Paired t test was employed to analyse the comparison of the circulatory dynamics of the lumbar muscles between, before and during the exercises. With respect to the comparison of the change rates of the muscular activities and circulatory dynamics among each of the exercises, we employed the one-way analysis of variance (ANOVA) (p < .05). The lumbar muscular activities during the walking were significantly higher than those during the bicycle ergometer exercise were at each load level. The Oxy-Hb increased significantly during the 25W and 50W bicycle ergometer exercises, as opposed to before the exercises. It showed a tendency to decrease during the 75W bicycle ergometer exercise and walking, but not significant. The change rate of the Oxy-Hb during the 25W bicycle ergometer exercise indicated a higher value than that of the other exercises. The Deoxy-Hb, on the other hand, declined significantly in every exercise compared with those before the exercises, with no significant differences in the change rates between each of the exercises. Bicycle ergometer exercise has been suggested as an aerobic exercise permitting as much oxygen uptake as walking does, with fewer loads on lumbar muscles and less likelihood of inducing a hypoxic state on lumbar muscles.

In Asia, many activities of daily living (ADL) are performed while sitting cross-legged on the floor. This sitting posture rotates the pelvis in a more dorsal direction and lumbar lordosis is more flattened than while sitting on a chair. Sitting cross-legged induces a greater load on the intervertebral discs and spine, especially when in a slumped position that is known to increase disc pressure even more and to aggravate chronic low back pain (CLBP). Therefore, it is very important to instruct Asian people about the correct sitting posture. In addition, it is known that co-contraction of the deep spine-stabilizing muscles enhances lumbar segmental stability and the sacroiliac joint. However, little is known about the influence of co-contraction of the trunk deep muscles on spinal curvature while sitting cross-legged on the floor. The purpose of this study was to compare EMG (electromyographic) activity of the trunk muscles while slump cross-legged sitting with that during co-contraction of the trunk muscles and to investigate how this co-contraction influences spinal curvature. Ten healthy male volunteers (21.7 +/- 2.5 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. EMG signals were continuously recorded while slump sitting cross-legged and during co-contraction of the trunk muscles. 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 skin-surface and hand-held device, the "Spinal Mouse". More significant activities of the trunk muscles, with the exception of the rectus abdominis, were observed during co-contraction of the trunk muscles than while slump sitting cross-legged. The co-contraction of the trunk muscles resulted in significantly less thoracic and lumbar curvature and more sacral angle than while slump sitting cross-legged. The results of this study indicated that co-contraction of the trunk muscles while sitting cross-legged could bring about the correct thoracic and lumbar curvature, and effectively stabilize the lumbopelvic region, and decrease focal stress on passive structures.

Background: The study of brain activity has been studied with the use of various techniques like electroencephalography (EEG), magnetic resonance imaging (MRI), positron emission topography (PET) and magneto-encephalography (MEG). These techniques are unsuitable because of restriction of moving of subject's body while playing "shogi (Japanese Chess)" matching However, optical topography (OT) is possible to measure. Therefore, brain activity is here studied with use of OT.

Materials and method: The measurement and analyses of the activity of brain is carried out by cerebral blood flow with use of OT. The equipment of OP is 16-channel maximum OMM-2000 device (Shimadzu, Tokyo, Japan). Two subjects play the game, and the cerebral blood flow of only one subject is measured, since the capacity of the equipment is limited.

Results and conclusion: When the subject does decision-making for a matter of chance during the game, the right side of frontal part (Fp2) proves more activity than that of left side (Fp1), and proves that the activity of both parts of visual field (O1, O2) communicates each other. The present study with use of OT is highly useful for observing brain activity during play of shogi game.

The purpose of this study was to identify and compare the Electromyographic Fatigue Threshold (EMG(FT)) determined in the Vastus Lateralis (VL), Rectus Femoris (RF), Biceps Femoris (BF), Semitendinosus (ST) and Tibialis Anterior (TA) during stationary cycling in trained cyclists and non-cyclists. Using a cycle ergometer, 13 cyclists (28.4 +/- 6.9 years; 70.3 +/- 13 kg; 176.1 +/- 8.5 cm) and 11 non-cyclists (25.8 +/- 4 years; 73 +/- 9.1 kg; 175 +/- 6.4 cm), performed a maximum incremental test (ITmax) (90 rpm) to determine the (EMG(FT)). Maximal power output (W(PEAK)) reached by cyclists was higher than for non-cyclists (372.6 W and 248.9 W respectively) (P < 0.01). For the five muscles analyzed in cyclists, EMG(FT) occurred at 85.7% of cases in the VL, 92.9% in RE 78.6% in BE 78.6% in ST and 50% in TA, while in the non-cyclists group, this occurrence was 100% to muscle VL, 100% to RF, 92.6% to BF, 78.6% to ST, and 78.6% to TA. Analyzing the percentage corresponding to the power at EMG(FT) in relation to W(PEAK) reached, no differences between groups were observed for RF, BF and ST, however VL and TA, as well as the mean from all muscles were lower for cyclists than non-cyclists (P < 0.05). The present results showed that EMG(FT) is more easily identified in RF and VL muscles for both groups, and it may be an interesting method to evaluate the adaptive responses from aerobic and anaerobic metabolisms during cycling training programs.

The aim of present study was to compare the alterations in electromyography signs with Ventilatory Threshold (VT). Had been part of the study eight men, amateur cyclists and triathletes (25.25 +/- 6.96 years), that they had exercised themselves in a mechanical cicloergometer, a cadence of 80 RPM and with the increased intensity being in 25 W/min until the exhaustion. The VT was determined by a non-linear increase in VE/VO2 without any increase in VE/VCO2 and compared with the intensity corresponding to break point of amplitude EMG sign during the incremental exercise. The EMG--Fatigue Threshold (FT) and Ventilatory Threshold (VT) parameters used were the power, the time, absolute and relative VO2, ventilation (VE), the heart hate (HH) and the subjective perception of the effort. The results had not shown to difference in none of the variable selected for the corresponding intensity to VT and FT--EMG of the muscles lateralis vastus and femoris rectus. The parameters used in the comparison between the electromyographic indicators and ventilatory were the load, the time, absolute VO2 and relative to corporal mass, to ventilation (VE), the heart frequency (HH) and the Subjective Perception of the Effort (SPE).

Background: The neurological manifestations of Crohn's disease are rare, dominated by multiple mononeuropathies, peripheral neuropathies (PN) of axonal and demyelinating types, myopathies and the abnormalities of the white matter. In our study, we aimed to report electrophysiological follow-up of a patient with chronic polyradiculoneuritis associated with newly diagnosed active Crohn's disease.

Case: A 32-year-old male patient was admitted with the complaints of abdominal pain and diarrhea for three years and an ascending weakness of all four extremities since two years. On his medical history he did not have any other disease and none of the members of his family had similar complaints. The neurological examination revealed a weakness of the especially distal muscles (2-3/5) with areflexia, hypotonia and distal atrophia in all extremities. He also had a glove and stocking hypoestesia. Routine biochemical and hematological examination were in normal ranges except C-reactive protein. The analysis of the cerebrospinal fluid showed an albumino-cytological dissociation.

Conclusion: Our results suggest that peripheral neurological findings could be regarded as a possible extraintestinal manifestation of Crohn's disease. It is important to remember that inflammatory bowel diseases may be a reason for a newly diagnosed polyneuropathy (acute or chronic demyelinated polyneuropathy) and therefore detailed examinations are needed if the patients do not have the commonly observed reasons for the development of polyneuropathy and be careful in inflammatory disease patient to develop polyneuropathy.

Severe cervical Spinal Cord Injury (SCI) leads to quadriplegia, and autonomic dysfunctions. Bladder/bowel continence, cardiovascular performance, and breathing are impaired besides movements. Even though there are no fully restorative treatments for SCI, I report about a patient, who suffered a severe cervical, motoric complete SCI, in whom urinary bladder functions were fully repaired by functional and structural repair (limited regeneration of the cord) upon 2.5 years of Coordination Dynamics Therapy (CDT). On the repair of the blood circulation (no occurrence of pressure ulcers any more), breathing and motor functions was reported earlier. The mechanism that underlies this important repair of urinary bladder functions is the learning transfer from movements to bladder functions. The human bladder repair is analyzed at the neuron level, the collective variable level (System Theory of Pattern Formation), the movement, and the clinical diagnostic level.

The present study investigated the influence of a regular Physical Therapy program with emphasis on proprioceptive stimulation, on the center pressure trajectory and muscle adjustments necessary to maintain balance on orthostatic position. After medical assessment, 29 subjects (63.06 +/- 2.84 years) were submitted to electromyographic and baropodometric evaluation and, subsequently, to a program of 12 weeks of physical therapy intervention focusing on proprioceptive stimulation. The oscillation of the pressure center (Pressure platform-MatScanTekscan) was evaluated concomitantly to electromyographic signal envelopment and median frequency assessment of anterior tibial and gastrocnemius muscles (signal conditioner module--MCS 1000-V2-LYNX ). The Wilcoxon test was used for comparison of means, with the significance level of 5%. The pressure center trajectory unipodal position with open eyes (UO) decreased significantly after physical therapy intervention. In this position, there was a reduction of the electromyographic signal envelopment and an increase on median frequency of the gastrocnemius muscle, while the anterior tibial muscle showed increased median frequency after intervention. For the unipodal position with closed eyes (UC), the anterior tibial muscle showed significant electromyographic signal envelopment decrease and increase of median frequency, which also increased for the gastrocnemius muscle. It is concluded that the physical therapy intervention promoted decrease of body oscillation, recruitment improvement and adjustment of the gastrocnemius and anterior tibial muscles, contributing to the postural balance improvement in orthostatic position on senior population.

The present study analyzed the effect of different magnitudes of isometric contraction of longissimus thoracis muscle until fatigue by means power spectra analysis. Eight healthy male subjects volunteered for this study The electromyography signals were sampled at 1 kHz using surface electrodes placed bilaterally over the longissimus thoracis muscle at the level L1. The isometric contraction was made at 30% and 60% of isometric maximal voluntary contraction (MVC) randomly in the MA ISOSTATION 2001 with the trunk at 45 degrees of flexion. A gain of 1000, a high pass filter at 20 Hz and low pass filter at 500 Hz was used. The endurance time with the load of 30% was longer than the load of 60%. It was found a significant drop in the median frequency and in the mean power frequency for both loads in both sides with progression of time. Also, analyzing the load effect, it was found significant differences in the total power and peak power for the longissimus thoracis in the interval of 0-100%, with lower values to 30%. The present study allows verifying the longissimus thoracis muscular fatigue by means the electromiographics parameters. It was showed that the total power and the peak power variables are sensible due changes in the load, once there are low values for the low loads.

The purposes of this study were threefold: (1) to compare the isometric torque-related patterns of absolute and normalized electromyographic (EMG) amplitude and mean power frequency (MPF) responses for electrode orientations that were parallel and perpendicular to the muscle fibers; (2) to examine the influence of electrode orientation on mean absolute EMG amplitude and MPF values; and (3) to determine the effects of normalization on mean EMG amplitude and MPF values from parallel and perpendicular electrode orientations. Ten adults (5 men and 5 women mean +/- SD age = 23.8 +/- 2.3 years) volunteered to participate in the investigation. Two sets of bipolar surface EMG electrodes (20 mm center to center) were placed parallel and perpendicular to the muscle fibers over the biceps brachii. The subjects performed a maximal voluntary isometric contraction (MVIC) test followed by randomly ordered submaximal muscle actions in 10% increments from 10 to 90% MVIC. Paired t-tests indicated that absolute EMG amplitude values for the parallel electrode orientation were greater (p < 0.05) than those for the perpendicular orientation at all isometric torque levels except 10% MVIC For normalized EMG amplitude values, however, there were no significant mean differences between electrode orientations. There were also no differences between electrode orientations for absolute or normalized EMG MPF values. In 30% of the cases, different torque-related patterns of responses were observed between the parallel and perpendicular electrode orientations for the absolute and normalized EMG amplitude and MPF values. Therefore, the results of the present study support the need for standardizing electrode orientation to compare the pattern of responses for EMG amplitude and MPF values and normalizing EMG amplitude data to compare the mean values.