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At least 595 records · Page 33Linked to original sources
PubMed1986

Predictive value of manual muscle testing and gait analysis in normal ankles by dynamic electromyography.

Eight muscles about the ankle of seven normal subjects were assessed by electromyography (EMG) during manual muscle testing (MMT) and walking. Three strength levels (normal, fair, trace) and three gait velocities (free, fast, slow) were tested. The muscles studied included the gastrocnemius, soleus, posterior tibialis, flexor digitorum longus, flexor hallucis longus, anterior tibialis, extensor digitorum longus, and extensor hallucis longus. Relative intensity of muscle action was quantitated visually (using an eight-point scale based on amplitude and density of the signal). The data showed that EMG activity increased directly as more muscle force was required during the different manual muscle test levels and increased walking speeds. No MMT isolated activity to the specific muscle though being tested. Instead, there always was a synergistic response. Both the gastrocnemius and soleus contributed significantly to plantarflexion regardless of knee position. The intensity of muscle action during walking related to the manual muscle test grades. Walking at the normal free velocity (meters/min) required fair (grade 3) muscle action. During slow gait the muscle functioned at a poor (grade 2) level. Fast walking necessitated muscle action midway between fair and normal, which was interpreted as good (grade 4).

Ankle↗
PubMed2004

Combining technologies: a computerized occlusal analysis system synchronized with a computerized electromyography system.

Current advances in computer technologies have afforded dentists precision ways to examine occlusal contacts and muscle function. Recently, two separate computer technologies have been synchronized together, so that an operator can record their separate diagnostic data simultaneously. The two systems are: the T Scan II Occlusal Analysis System and the Biopak Electromyography Recording System. The simultaneous recording and playback capacity of these two computer systems allows the operator to analyze and correlate specific occlusal moments to specific electromyographic changes that result from these occlusal moments. This synchronization provides unparalleled evidence of the effect occlusal contact arrangement has on muscle function. Therefore, the occlusal condition of an inserted dental prosthesis or the occlusal scheme of the natural teeth (before and after corrective occlusal adjustments) can be readily evaluated, documented, and quantified for both, quality of occlusal parameters and muscle activity and the responses to the quality of the occlusal condition. This article describes their synchronization and illustrates their use in performing precision occlusal adjustment procedures on two patients: one who demonstrates occlusal disharmony while exhibiting the signs and symptoms of chronic myofascial pain dysfunction syndrome, and the other who had extensive restorative work accomplished but exhibits occlusal discomfort post-operatively.

Adult↗
PubMed2005

Home-based electromyography-triggered stimulation in chronic stroke.

OBJECTIVES: (1) To determine the feasibility of a home-based electromyography-triggered neuromuscular stimulation (ETMS) programme; and (2) to determine ETMS efficacy in increasing affected wrist extension and reducing affected arm impairment. DESIGN: Randomized, controlled, pre-post, cross-over design. SETTING: Outpatient rehabilitation hospital. PATIENTS: Twelve chronic stroke patients with palpable muscle contraction in their affected wrist extensors but no movement (7 males; mean age = 59.75 years, age range 44-75 years; mean time since stroke = 52.75 months, range 13-131 months). INTERVENTION: Subjects were randomly assigned to receive either: (a) ETMS use twice every weekday in 35-min increments during an eight-week period followed by an eight-week home exercise programme (ETMS/home exercise programme) (n=8); or (b) an eight-week home exercise programme followed by use of ETMS twice every weekday in 35-min increments during an eight-week period (home exercise programme) (n=4). MAIN OUTCOME MEASURES: The Fugl-Meyer, Action Research Arm Test and goniometry. RESULTS: After home exercise programme participation, subjects showed nominal or no changes on any of the outcome measures. After ETMS, patients showed modest impairment reductions, as shown by the Fugl-Meyer, and no Action Research Arm Test changes. However, both groups showed a 21 degree increase in active affected wrist extension after ETMS use. CONCLUSION: ETMS use is feasible in the home environment. Neither participation in a traditional home exercise programme nor ETMS use conveyed changes on the Fugl-Meyer or Action Research Arm Test. However, ETMS use increased active affected limb extension. This new movement may provide a potential pathway for subjects to participate in other interventions, such as modified constraint induced therapy.

Adult↗
PubMedDate not supplied

A comparison of static and dynamic wrist splints using electromyography in individuals with rheumatoid arthritis.

This study compared strength, dexterity, and the muscle activation of individuals with rheumatoid arthritis (RA) when different splints were worn. Five persons with RA were observed in four splint conditions (none, static, hinged, spiral) during grip, pinch, and dexterity tests by recording muscle activity of eight muscles in the upper extremity using electromyography (EMG). Statistically significant differences were found in clinical tests when hinged (p<0.001) and spiral splints (p=0.02) were worn. Grip strength decreased when hinged splints were worn, whereas two-point pinch increased and dexterity improved on the Nine-Hole Peg Test with the spiral splint. Although no significant EMG differences were found during different splint conditions, wrist muscles were recruited more for grip, and shoulder muscles were used most during pinch and dexterity tests. Individuals with RA who wore splints had decreased grip when wearing hinged splints, but improved pinch and dexterity were found when the spiral splint was worn. Increased use of proximal shoulder muscles was observed during pinch and dexterity tests with and without splints.

Adult↗
PubMed1975

Myasthenia gravis with features of the myasthenic syndrome. An investigation with electrophysiologic methods including single-fiber electromyography.

A 47-year-old woman had myasthenia gravis with only moderate weakness and a consistently poor response to anticholinesterase medication. She was investigated with routine electrophysiologic studies and single-fiber electromyography. The studies showed a limited effect of anticholinesterase medication. There was a decrement to 2 Hz stimulation of not less than 25 percent regardless of medication and administration of edrophonium. With faster rates of stimulation (10 to 20 Hz), there was a facilitation up to 190 percent. In addition, with postcontractive or post-tetanic potentiation the action potential in the abductor digiti minimi muscle was increased from the initial value of 2.5 mv or less to up to 6 mv. Single-fiber electromyographic investigations showed increased jitter and blocking with little response to drugs, as well as facilitation in a large number of motor end-plates in association with both voluntary activity and repetitive stimulation. The findings indicated a mixture of phenomena seen in myasthenia gravis and the myasthenic syndrome.

Action Potentials↗
PubMed1976

Multiple sclerosis and myasthenia gravis. A case report with single fiber electromyography.

A 34-year-old woman with long-standing multiple sclerosis had a 2-year history and physical signs of myasthenia gravis. The edrophonium chloride (Tensilon) test was positive. Repetitive stimulation of the ulnar nerve at 3 Hz did not show evidence of myasthenic response; however, a single-fiber electromyography demonstrated evidence of neuromuscular block as seen in myasthenia gravis, which was reversed to normal after intravenously administered edrophonium. The patient improved on anticholinesterase medication. It is suggested that patients with multiple sclerosis who have unusual features such as in the patient reported here should be investigated for the presence of myasthenia gravis to ensure proper treatment.

Adult↗
PubMed1978

The description of motor unit potentials in electromyography.

It has been suggested that the findings on needle electromyography should be described by abbreviations such as "SSAP" rather than "myopathic." The patterns of changes that may occur and their pathophysiologic basis make both of these terms unsuitable. Quantitative measurements are needed.

Action Potentials↗
PubMed1983

End-plate spikes in electromyography are fusimotor unit potentials.

Spontaneous negative-positive potentials (NPPs) in electromyography were often activated by movement of the needle electrode or by tetanic stimulation. Coactivation of NPPs was sometimes observed in voluntary effort. Circulatory arrest or hyperventilation had no consistent effect. These facts and the differences of firing of NPPs from usual ectopic firing patterns indicate that NPPs are not driven by ectopic activity of motor axons. Instead, the firing of NPPs is similar to activity of muscle spindle afferents during fusimotor drive. We believe that NPPs are action potentials of intrafusal muscle fibers driven by gamma motor neurons.

Action Potentials↗
PubMed1987

Single-fiber electromyography is a sensitive indicator of axonal degeneration in diabetes.

Axonal degeneration with reinnervation was assessed in diabetic subjects with single-fiber electromyography (SF-EMG). SF-EMG was performed on 18 control subjects, 20 diabetic control subjects without clinical or electromyographic evidence of polyneuropathy, and 30 diabetic subjects with clinical and electromyographic features of polyneuropathy. In the diabetic controls and diabetic neuropathy subjects, fiber density and jitter were increased indicating axonal degeneration with reinnervation. These findings confirm that axonal degeneration is a principal pathologic mechanism in diabetic polyneuropathy and that axonal degeneration commonly occurs in asymptomatic diabetic subjects. SF-EMG is thus a sensitive method for assessing axonal degeneration in diabetic subjects.

Adult↗
PubMed1979

Use of anal sphincter electromyography during operations on the conus medullaris and sacral nerve roots.

The mechanical activity of the anal sphincter can be translated into electrical activity and recorded on graph paper or an oscilloscope. The activity of the anal sphincter may be extrapolated to activity of the external urethral sphincter because both are striated muscles innervated by the pudendal nerve that arises from S-2, S-3, and S-4. Stimulation of these nerves causes contraction of the sphincter muscles, and a deflection of the recording device occurs. This technique was employed intraoperatively in monitoring operations on the conus medullaris and sacral nerve roots in 10 patients with spinal dysraphism (age range, 3 weeks to 15 years). Their diagnoses were tethered conus, 4; lipomeningocele, 3; spinal hamartoma, 1; syringocele, 1; and sacral arachnoiditis, 1. With general anesthesia, and the patient in the prone position, an electrode-containing anal plug was inserted or two needle electrodes were inserted into the anal sphincter muscle. The electrodes were connected to the electromyography recording stylus of the urodynamic bladder diagnostic unit. During the spinal operation, whenever a structure could not be identified clearly, it was stimulated with the disposable electrical stimulator and, if oscillations of the stylus occurred (indicating contraction of the anal sphincter), the structure was preserved. This technique permitted spinal operations in these 10 patients without changes in neurological or urological function.

Adolescent↗
PubMed2005

The initial use of free-running electromyography to detect early motor tract injury during resection of intramedullary spinal cord lesions.

OBJECTIVE: The resection of intramedullary spinal cord lesions (ISCLs) can be complicated by neurological deficits. Neuromonitoring has been used to reduce intraoperative risk. We have used somatosensory evoked potentials (SEPs) and muscle-derived transcranial electrical motor evoked potentials (myogenic TCE-MEPs) to monitor ISCL removal. We report our retrospective experience with the addition of free-running electromyography (EMG). METHODS: Thirteen patients underwent 14 monitored ISCL excisions. Anesthesia was maintained with minimal inhalant to reduce motoneuron suppression and enhance the myogenic TCE-MEPs. Free-running EMG was examined in the four limbs for evidence of abnormal bursts, prolonged tonic discharge, or sudden electrical silence. Warning of an electromyographic abnormality or myogenic TCE-MEP loss prompted interventions, including blood pressure elevation, a pause in surgery, a wake-up test, or termination of surgery. Pre- and postoperative neurological examinations determined the incidence of new deficits. RESULTS: The combined use of free-running EMG and myogenic TCE-MEPs detected all eight patients with a new motor deficit after surgery; there was one false-positive report. In three of the eight true-positive cases, an electromyographic abnormality immediately anticipated loss of the myogenic TCE-MEPs. Two patients with abnormal EMGs but unchanged myogenic TCE-MEPs experienced mild postoperative worsening of motor deficits; myogenic TCE-MEPs alone would have generated false-negative reports in these cases. CONCLUSION: During resection of ISCLs, free-running EMG can supplement motor tract monitoring by TCE-MEPs. Segmental and suprasegmental elicitation of neurotonic discharges can be observed in four-limb EMG. Abnormal electromyographic bursts, tonic discharge, or abrupt electromyographic silence may anticipate myogenic TCE-MEP loss and predict a postoperative motor deficit.

Adolescent↗
PubMed1987

Telemetered electromyography of the fast and slow extensors of the leg of the brown lemur (Lemur fulvus).

Quantitative telemetered electromyography from the four heads of the quadriceps femoris (vastus medialis, rectus femoris, vastus intermedius and vastus lateralis) during normal postures and locomotion (quadrupedal resting, walk/run, gallop and leaping) is presented for the brown lemur, Lemur fulvus. The vastus intermedius is the sole contributor to muscle recruitment during quadrupedal resting postures. It exhibits consistently high levels of electrical activity during all locomotory behaviour. The vastus medialis is recruited least among these muscles during walk/run and tends to be 'saved' for galloping and leaping. The rectus femoris and vastus lateralis are recruited at similarly high levels during all phasic activities. The rectus femoris appears to be used eccentrically, storing 'elastic strain energy' during all phasic activities. The vastus lateralis combines exceptionally high potential effective force with relatively high potential velocity and resistance to fatigue and probably develops the majority of force in all phasic activities. These results support previously documented structural and histochemical data that imply a functional division of labour among these muscle synergists.

Animals↗
PubMed1989

Electromyography of the fin musculature of the cuttlefish Sepia officinalis.

The musculature of the fins of the cuttlefish Sepia officinalis (Mollusca, Cephalopoda) was studied with electromyography to test predictions of the functional role of the various muscle masses. Previous research had shown the fins to consist of a tightly packed, three-dimensional array of muscle with distinct zones of anaerobic glycolytic and oxidative muscle fibres. In addition, a network of crossed oblique connective tissue fibres was observed within the musculature. In a previous paper a model of the function of the muscle and connective tissue was presented. In the present paper, we present recordings of electrical activity from the various muscle bundles in the fin, in conjunction with the output from an electronic movement-monitoring device, and correlate muscle activity with both the phase and the intensity of the fin-beat cycle. The results obtained here support the hypothesis that the oxidative muscle fibres produce gentle fin movements and are consistent with the hypothesis that the network of crossed oblique connective tissue fibres provides skeletal support. The results also support predictions that the anaerobic glycolytic muscle fibres both produce vigorous fin movements and provide support for that movement. This study provides a critical test of models of the role of the tightly packed, three-dimensional array of muscle found in muscular hydrostats such as the arms and tentacles of cephalopods and tongues of mammals and lizards.

Animals↗
PubMed2005

Mastication effort estimated by electromyography for cooked rice of differing water content.

The objective of this study was to quantify the mastication effort for cooked rice. We analyzed mastication patterns while normal subjects ate a spoonful of cooked rice that had been prepared by cooking with different amounts of water (1.5, 2.0, 3.0, and 4.0 times the water to rice weight). The rice samples were served with the same weight, same volume and same solid content, and electromyography (EMG) of the masticatory muscles was measured. The texture of the four cooked rice samples was instrumentally analyzed by the two-bite method. The number of chews, masticatory time, and jaw-closing muscle activities per chew evaluated by EMG were higher in the rice sample cooked with least water, which exhibited a high firmness value in the instrumental test. Rice cooked with 4.0 times the amount of water exhibited the longest jaw-opening duration, which was related to the adhesiveness value in the instrumental test. The ratio of jaw-opening muscle activity to the preceding jaw-closing muscle activity was lower for the rice containing least water, this corresponding to the area ratio (balance degree) in the instrumental test. Softer rice containing more water reduced the total mastication effort until swallowing because it required a shorter mastication time. It was not difficult for the softer rice with high density to be ingested in greater weight, decreasing the mastication effort for a certain amount.

Adult↗
PubMed1985

Simultaneous manometry and electromyography in the pharyngoesophageal segment.

Whether the occlusion between hypopharynx and esophagus is established by anatomical relations and tissue elasticity or by a functional resting tone of the muscle fibers is not quite clear. This study describes simultaneous electromyography (EMG) and electromanometry in the pharyngoesophageal segment to solve this problem and investigate the complex mechanism of deglutition. To register the EMG from the hypopharyngeal constrictor muscle and the upper esophageal sphincter (UES), two copper wire electrode pairs with hooked bare ends were used. These electrodes were introduced into the muscles through a rigid esophagoscope. It is demonstrated that at rest muscle activity is present in the UES. This activity disappears during the relaxation period. Simultaneous manometry and EMG is a valuable supplement to diagnostic procedures in dysphagia patients.

Deglutition↗
PubMed1985

Predictive value of laryngeal electromyography in patients with vocal cord paralysis of neurogenic origin.

Laryngeal electromyography can provide prognostic information when evaluating patients with vocal cord dysfunction. Twenty-four patients were studied to determine the predictive capacity of this test. Six patients had bilateral vocal cord paralysis, constituting a total of 30 vocal cords examined. Sixteen of these cords had decreased or absent motor unit potentials, fibrillations, or positive waves. None of these patients recovered function. Fourteen cords demonstrated either normal motor unit or polyphasic potentials. Return of mobility was evident in 11 of these cords. The combined total was 27 of 30 cords correctly predicted, demonstrating a 90% accuracy rate.

Action Potentials↗
PubMed1990

A new method of needle-electrode placement in the posterior cricoarytenoid muscle for electromyography.

In 1979 the authors developed a new method of needle-electrode placement in the posterior cricoarytenoid muscle (PCA) for electromyography. The PCA muscle is easily reached by inserting a needle electrode through the cricothyroid membrane at the midline and penetrating the lamina of the cricoid cartilage in the subglottic cavity. Access to the PCA muscle for electrode insertion was best afforded by a percartilaginous approach. This report details the new technique used at our laboratory. To our knowledge, this is the first report of needle-electrode placement in the PCA muscle by a percartilaginous approach. This new electrode insertion technique has been applied to more than 100 dogs for research purposes and to 1200 patients with laryngeal motor disorders for clinical diagnosis. This is a simple technique requiring the usual skills. Reliable electromyographic recordings have been obtained by this new method. No untoward effects, such as hematoma or infection from repeated placements were observed in approximately 3200 examinations performed to date. It is reasonable to assume that the percartilaginous route for electrode insertion in the PCA muscle is feasible in man. Techniques of electrode placement in the intrinsic laryngeal muscles are reviewed and compared.

Adolescent↗