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PubMed1979

[Use of electromyography of the bladder sphincter for the differentiation of prostate adenoma and prostate carcinoma].

82% of the male patients with healthy urogenital tract showed an isoelectric line in the simultaneous EMG-derivation of the sphincter of the bladder under conditions of rest; in 18% of the males a moderate activity was present. In voluntary innervation at once an intensive electric activity of a spindle-shaped discontinuous pattern of the action potential developed in 76% of the patients. In the pressing trial in 83% of the cases a slight to moderately strong activity appeared. In contrast to the examined patients with healthy outlet of the vesicle the patients in whom an adenoma of the prostate gland or a carcinoma of the prostate gland, respectively, was present exhibited deviations from the normal pattern of the action potential, in which cases carriers of adenoma and carcinoma differed. Whether and to what extent the electromyography on the m. sphincter vesicae allows the possibility of the differentiation between adenoma of the prostate gland and carcinoma of the prostate gland in the early clinical stage shall be reserved for further examination.

Adolescent↗
PubMed1996

Electromyography of levator scapulae: new findings allow tests of a head stabilization model.

OBJECTIVE: Understanding the recruitment patterns of shoulder girdle prime-mover muscles will allow meaningful exploration of non-prime-mover neck muscle activity during arm and shoulder efforts. This study identifies exercises that isolate recruitment of levator scapulae from recruitment of upper trapezius. The exercises will be used for electromyographic experiments in which the head stabilizing roles of other neck muscles will be explored. DESIGN: Right levator scapulae and upper trapezius were electromyographically monitored with indwelling, fine-wire, bipolar electrodes. Subjects performed isometric arm exercises and movements of the upper limb, shoulder and head. SETTING: Electromyography facilities of the department of Anatomical Sciences of the State University of New York at Stony Brook were used. PARTICIPANTS: Six adult subjects participated; one had reduced shoulder girdle mobility and a history of multiple shoulder separations. MAIN OUTCOME MEASURES: Raw electromyographic data were scored visually on a scale from 0 to 4, with 4 being the signal observed in a maximal voluntary contraction. RESULTS: All subjects recruited levator scapulae alone during arm extension. Only the subject with reduced shoulder mobility recruited levator scapulae during scapular plane arm elevation and arm abduction. CONCLUSIONS: The levator scapulae torque to be counteracted in arm extension produces ipsilateral rotation, lateral flexion and extension of the neck; trapezius rotates the head contralaterally during scapular plane arm elevation. These distinct and relatively simple cases (one shoulder girdle prime-mover affecting head posture at a time) are appropriate exercises for experimental exploration of the recruitment patterns of potential head stabilizers during arm/shoulder efforts.

Adult↗
PubMed1995

[Value and role of electromyography in the assessment and prognosis of disorders of laryngeal mobility].

Although it was described many years ago, laryngeal electromyography is of limited use. It can easily be performed in the doctor's surgery by the intercrico-thyroid approach. The author reports on 70 examinations, 64 for mobility disorders, 6 for abnormal spasmodic movements. 15 normal plots made it possible to correct a faulty diagnosis of palsy. The prognostic contribution is not so clear-cut and must take account of the clinical circumstances and the time elapsed before examination. EMG must be performed systematically before any irreversible therapeutic decision.

Electromyography↗
PubMed1996

Comparison of anal sonography with conventional needle electromyography in the evaluation of anal sphincter defects.

OBJECTIVE: A comparison of anal sonography with conventional electromyographic mapping in the evaluation of anal sphincter defects was the aim of this study. METHODS: In 23 patients with defecatory problems referred for conventional needle electromyography (EMG), anal endosonography, with a 7.5-MHz, 355 degrees scanner, was performed before EMG to determine the structural integrity of the external anal sphincter. If lesions were found, they were described in terms of location and extent. Subsequently, concentric needle EMG of the external sphincter was performed circumferentially to locate muscle parts exhibiting normal and diminished or missing muscle activity. Lesions found by EMG were also described like those found by sonography. RESULTS: Of 23 patients, eight exhibited no abnormalities on EMG, and no muscle defects were identified endosonographically in any of these patients. In the remaining 15 patients, EMG showed either an incomplete pattern of interference or a complete absence of voluntary activity; in all of these patients endosonography also identified structural deficit. In 14 of these 15 patients, abnormalities were found at the same location with both endosonography and EMG. In the remaining patient, the two techniques identified structural and functional abnormalities at different locations. CONCLUSION: Although EMG is the gold standard for assessment of the functional relevance of muscle defects, anal endosonography yields a sensitivity and specificity of almost 100%.

Adult↗
PubMed1996

[Value of electromyography in diagnosis of incontinence].

Electromyography (EMG) of the pelvic floor musculature is only carried out as a routine method in few clinics. There is a lack of standard patient groups and, correspondingly, standardized values do not exist. Close cooperation between proctologists and neurologists is the exception. Some surgeons use the EMG to evaluate muscular defects (mapping), however sonography is a less invasive method to detect these lesions. It is the real domain of the EMG to provide qualitative and quantitative evidence of neurogenic lesions, which means that it allows to differentiate between central and peripheral as well as between acute and chronic lesions. It also enables the experienced neurophysiologist to estimate the prognosis and to give an expert opinion. Optimum utilization of the method is only possible with interdisciplinary cooperation.

Anal Canal↗
PubMed1997

A special kind of anterior horn cell involvement in juvenile myoclonic epilepsy demonstrated by macro electromyography.

Juvenile myoclonic epilepsy (JME) is not an uncommon seizure disorder, occurring in 5-10% of epileptic patients. A subclinical anterior horn cell involvement has been suggested in some JME patients by concentric needle electromyography (EMG) and turn/amplitude analysis. In this study, 22 JME patients and 17 normal control subjects have been studied with macro EMG, which is a sensitive method to assess the size of motor units. Most JME patients (19 of 22) had a pathologically increased number of individual large macro motor unit action potentials (MUAPs) compared to control subjects. For both biceps brachii and tibialis anterior muscles, means of median macro MUAP amplitudes were significantly greater than those of normal controls, whereas the fiber density values were only slightly increased. This suggested another kind of anterior horn cell involvement in JME than seen in motor neuron diseases.

Action Potentials↗
PubMedDate not supplied

[The use of brain stem auditory evoked potentials and electromyography in the monitoring of cranial nerves during skull base surgery].

Cranial nerves and the brainstem are at risk of being injured during skull base operations. The result might be the patient's death or severe neurological deficits. Brainstem auditory evoked potential is an accepted method of intraoperative auditory nerve or brainstem monitoring. Other cranial nerves are monitored using electromyography and evoked muscle activity recorded from appropriated muscle groups.

Cranial Nerves↗
PubMed1997

The relationship between electromyography and work intensity revisited: a brief review with references to lacticacidosis and hyperammonia.

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 of 60 Watts with a 30 Watt.4 min-1 work increment. Each test was terminated at exhaustion. Blood was collected at the end of each work intensity for lactate and ammonia analysis. EMG were recorded from the vastus lateralis, rectus femoris and vastus medialis using pre-amplified surface electrodes. EMG were collected at each intensity over a period of 60 cycle revolutions. EMG signals were analyzed using integration and EMG spectral analysis. Gas exchange variables were recorded on-line for each test (15 second interval). Ammonia and lactate threshold points were surpassed at the same absolute work intensity (200 Watts) which was equivalent to 64-69% VO2max. When a linear model was applied to the iEMG data, coefficients of determination achieved were greater than those obtained when an exponential model was used for the vastus lateralis and medialis. Gradients of regression lines fitted to iEMG data at pre- and post-lactate/ammonia threshold work intensities were not different. Alternatively, the iEMG-work intensity relationship for the rectus femoris muscle tended to be curvilinear. Significant increases in iEMG were observed at post-lactate/ammonia threshold work intensities for the rectus femoris reflecting increases in fatigue and type II motor unit recruitment at these intensities. In general, median frequency of the EMG power spectrum function were unchanged during incremental work, although highly individualistic results were observed between some subjects and muscles. Grouped median frequency values were insensitive to changes in recruitment, metabolite accumulation and fatigue associated with the increases in work intensity. Consequently, the usefulness of EMG spectral analysis during incremental work was questioned.

Acidosis, Lactic↗
PubMedDate not supplied

Electromyography study of the portions of the abdominal rectus muscle.

This study objective was to verify the behavior of three portions of the abdominal rectus muscle through a quantitative analysis of the electromyographic signal in different types of abdominal exercises. Ten young male between 16 and 27 years old were studied and they had no previous history of muscle and joint illness. They were well-trained and did seven abdominal exercises chosen considering the types of contraction (isotonic and isometric) as well as the muscle fixation points. The electric activity of the superior, medium (above umbilicus) and inferior (below umbilicus) portions at the left side of the abdominal rectus muscle was taken using Beckman type surface mini-electrodes. The registers were collected from computerized 8-channel Nicholet electromyography equipment, model Viking II. The signals were quantified using the MVA (Maximum Volunteer Activity) software, being considered for analysis the values of RMS (Root Mean Square). The obtained data were submitted to a parametric analysis using the variance analysis (F test) and also the Tukey test, besides a descriptive graphic analysis starting from the average RMS values of each muscle portion. This study results suggest that for the majority of the subjects, the functional activities of the abdominal rectus muscle are performed with electric activity differences among their portions, showing a tendency of producing more electric activity in the superior portion than in the medium and inferior portions. The experiment also demonstrated an absence of a common behavior pattern in the three portions of the ten tested subjects.

Adolescent↗
PubMedDate not supplied

[Electromyography of the penis in the diagnosis of erectile dysfunction after radical operations on the organs of the lesser pelvis].

The paper presents the technique and results of electromyography of the penis (EMP) for 68 males divided into 3 groups: 21 volunteers with erectile disorders, 20 patients with nonvasculogenic erectile dysfunction and no history of pelvic operations, 27 patients with erectile abnormalities as a result of pelvic operations (after cystectomy -11, cystoprostatectomy -1, rectal resection -7, rectal extirpation -8 patients, groups 1, 2, 3 and 4, respectively). Autonomic innervation of the penis is primarily characterized by such EMP parameters as amplitude, synchronism and frequency of potentials. Neurogenic penile disorder was identified in 3 patients of group 2 (1 patient with intervertebral disk hernia, 2 patients with lumbosacral osteochondrosis), in all patients of group 3 (electric silence was recorded in 22 patients). EMP should be included in the algorithm of examination of patients with erectile dysfunction as providing a reliable assessment of autonomic penile innervation.

Adolescent↗
PubMedDate not supplied

Prevalence of hyperactive digastric muscles during swallowing as measured by electromyography in patients with myofascial pain dysfunction syndrome.

One purpose of this clinical study is to establish a relationship between the hyper activity of the digastric muscles and predisposition of an individual to MPDS (myofacial pain dysfunction syndrome). If a population predisposed to MPD could be identified by an early diagnosis, intervention and treatment could eliminate potential pain in adulthood. Secondly, can the employment of electromyography to aid in the diagnosis of patients with MPD be helpful in establishing a program of prevention and treatment? Thirty-one patients, male and female, were randomly selected from among those routinely diagnosed as having myofascial pain dysfunction syndrome by the dental staff at the Long Island Center for Craniofacial Pain. Eighteen patients who did not experience any symptoms of facial pain comprised the control group in the study. This study demonstrated that the average trace readings which indicate the activity of the digastric muscles, as measured by the electromyogram from patients experiencing facial pain were significantly higher than those from patients without pain symptoms. In every instance, the correlation between facial pain and abnormal swallow patterns which are a cause of hyperactivity of the digastrics was confirmed.

Adolescent↗
PubMed1998

[Measuring muscle relaxation with mivacurium in comparison with mechano- and electromyography].

Based on survey of the literature, methodological problems of electromyographic and mechanomyographic neuromuscular monitoring are presented. Often mechanomyography (MMG) is accompanied by mechanical problems during the registration of the contractions in the operating theatre. In contrast to mechanomyography the registration of electromyographic signals is easier whereas the processing of electromyographic signals is more difficult. In the operating theatre, registration problems can also occur with electromyography (EMG) from artefacts arising from stimulation impulses, high frequency apparatus and alternating current. During neuromuscular monitoring using MMG, a positive drift of the amplitudes of the contractions can be observed, whereas EMG leads to a negative drift of the amplitudes of the action potentials. Both observations can lead to misinterpretation of the degree of neuromuscular block measured by single twitch stimulation during the recovery period. Both the positive and negative drifts can be prevented by single twitch stimulation lasting for up to 10 minutes before the start of the neuromuscular monitoring of the effect of a given dose of a muscle relaxant. Finally, a clinical study of simultaneous registration of the MMG at the M. adductor pollicis and of the EMG at the M. interosseus dorsalis DI under total intravenous anaesthesia using propofol and alfentanil and muscle relaxation with a bolus dose of 75 mg/kg mivacurium is described. During the mechanomyographic studies, a decrease in the preload by an average of 1.2 Newton (N) with a maximum level of 4.0 N occurred. The decrease in preload was less than 25%. The mechanomyographically measured onset time of an ED95 of mivacurium amounted to 3.5 +/- 1.2 minutes on average and the degree of maximum neuromuscular block on average (95.1 +/- 5.6%) tallied very well with the expected value of 95.0%. The electromyographically measured onset time of an ED95 of mivacurium amounted to 4.3 +/- 1.2 minutes on average and the degree of maximum neuromuscular block amounted to only 91.3 +/- 8.1% on average. A comparison of the mechanomyographic values and the electromyographic values leads to the following results: the MMG showed a significantly shorter onset time (p < 0.0001) and a significantly deeper maximum neuromuscular block (p = 0.0004) than the EMG. There were also significant differences between mechanomyographically and electromyographically measured recovery values regarding T1(75) (p = 0.0007), T1(90) (p < 0.0001), TOF0.8 (p = 0.0386) and T1(25-75) (p < 0.0001). On average, an ED95 of mivacurium showed a significantly slower recovery in the mechanomyogram than in the electromyogram.

Adult↗
PubMed1997

[The new parameters of motor unit potential in the diagnosis of neurogenic lesions in spike-triggered averaging electromyography].

OBJECTIVE: To evaluate the clinical significance of the new parameters of motor unit potential (MUP) to the diagnosis of neurogenic lesions. METHODS: Three groups of muscles, anterior tibialis, abductor pollicis brevis and vastus medialis were studied with spike-triggered averaging electromyography (EMG). A total of 3,646 MUPs, 1,903 from normal group and 1,743 from neurogenic group, were recorded under slight muscle contraction. RESULTS: The area, as a single parameter, produced the most significant result in discriminant analysis, about 80% MUPs from neurogenic muscles being judged to be abnormal. Compared with the area, the amplitude and duration were less sensitive, being able to assign about 77% and 70% of MUPs in the neurogenic group as abnormal. A combination of the area/amplitude ratio (thickness) and the amplitude, and a combination of the duration (width) and the amplitude could further improve the discriminating ability, around 80% and 81% MUPs in the neurogenic muscles being classified as abnormal by the combinations. The simplified discriminant functions, 2 x Log10 (amplitude) +Log10 (area/amplitude) -4 for size index, and 5 x Log10 (duration) + 3 x Log10 (amplitude) -10 for width-height index had same discriminating ability as the real discriminant function. CONCLUSIONS: The new parameters, SI, WHI and area in spike-triggered EMG seemed to be promising, since they produced a better yield in the diagnosis of neurogenic lesions than amplitude or duration alone in the discriminant analysis.

Adolescent↗
PubMed1998

Role of thenar electromyography in the evaluation of carpal tunnel syndrome.

In the evaluation of CTS, electromyography of various myotomes as well as proximal and distal muscles remains quite useful in helping to assess other clinically suspected differentials such as plexopathy, systemic neuropathies, radiculopathies, and proximal nerve entrapments. With regards to T-EMG specifically, it can provide information regarding axonal loss; however, it only crudely estimates relative severity and prognosis. These are better and less painfully determined by nerve conduction studies. The addition of nerve conduction studies to the clinical assessment gives one the ability to diagnose, determine severity and prognosis, and determine best management. The addition of T-EMG in typical cases of CTS causes excess pain and adds little to the information already gained. Therefore the author suggests that T-EMG be reserved for atypical or unusual presentations when additional information is needed such as when nerve conduction studies cannot be performed or when the pathology is potentially aggressive causing significant axonal injury over a short time.

Axons↗
PubMed1994

Ergonomic assessment of handle design by means of electromyography and subjective rating.

Stress and strain during manual tool handling not only depend on factors such as weight to be handled, but are also determined by the design of the man-machine interface. In this study, three different handles of electric hedge-clippers were analysed; the results of a comparative investigation into the physiological cost demanded by the use of the different handles are discussed. Muscular strain was measured via surface electromyography in laboratory experiments with nine male subjects. The results showed significant differences in physiological cost depending on both work height and the handles' shape. Systematic differences in muscular strain between the utilized tools were found, despite the fact that all clippers were compensated with respect to weight and location of the centre of gravity. One of the handle designs enabled working under varying conditions (work height and direction) at a reduced level of muscular strain of the right arm. Results from the physiological evaluation were partly supported by the working persons' own subjective experience. The results of this investigation show that further ergonomic tool and handle design is necessary.

Journal Article↗
PubMed1995

Postural responses to platform perturbation: kinematics and electromyography.

Dynamic postural control may be studied using feedback paradigms which disturb standing balance. In this study the kinematics and electromyography of the reaction to an unexpected slip were examined simultaneously in 16 young, healthy volunteers to characterize the response to postural perturbation in the context of the perturbation characteristics. Kinematically, results showed ankle plantarflexion, knee flexion, hip extension, and shoulder flexion. Electromyographically, sequences of activation of the postural muscles of the leg were primarily anterior distal. Data is presented that supports a new model of the reaction to perturbation which incorporates the timing and type of muscular activity, the type of motion (active or passive), and the perturbation characteristics. RELEVANCE--:Understanding the interplay of the neurophysiological and biomechanical aspects of dynamic postural control gives insight into balance reactions. Simultaneous consideration of the kinematics, muscle activation, and perturbation characteristics allows a more comprehensive view of recovery of balance.

Journal Article↗
PubMed2005

Wireless on-line electromyography in recording neck muscle function: a pilot study.

AIM: The surface electromyography (SEMG) records muscle activity without causing pain and therefore it can be used in the on-line kinetic evaluation of rehabilitation methods. The cables are a problem in the clinical work. The aim of this pilot study was to introduce a wireless on-line SEMG method in the measurements of neck muscle activity and preliminarily evaluate its usability in dynamic exercises in a healthy and a neck pain subject. METHOD: The bilateral wireless on-line SEMG measurements were performed at the level C4-C5 of the cervical spine. The subjects (one healthy 32-year-old female and one neck pain patient, 35-year-old female) were performing slow cervical flexions with eyes open. The angle of the flexion was measured with inclinometer. RESULTS: In healthy subjects, the SEMG curve demonstrated clear flexion-relaxation rhythm whereas in the patient the rhythm was blurred. The SEMG signal quality was, however, good in both cases. CONCLUSION: Wireless on-line SEMG method seems promising in daily clinical work for the measurements of neck muscle activity.

Journal Article↗
PubMed1998

Electromyography in the biomechanical analysis of human movement and its clinical application.

This article introduces the area of scientific study of human movement. It is primarily intended for readers who wish to form a judgement on the usefulness of scientific movement analysis techniques in the treatment process of patients with abnormal movement patterns. With a focus on the analysis of human locomotion, the paper outlines the historical development of a biomechanical approach towards the understanding of human movement patterns. This approach alone proves to be inadequate in supplying reliable information on neuromuscular control of movement. It follows that electromyographic techniques are essential for this purpose. Scientific literature reveals relevant practical usability of such information. This is the rationale for a review of the historical, physiological, technical and methodological background of electromyographic analysis of movement. The field of management and rehabilitation of motor disability is identified as one important application area. On the basis of relevant literature, the present paper asserts that scientific analysis of human movement patterns can materially affect patient treatment. It provides evidence that patient management and rehabilitation processes in central neurological disorders can be improved through electromyographic techniques. In particular, this evidence supports the use of electromyography for surgical planning in children with cerebral palsy. The paper concludes with a view on future directions in research, development and applications of scientific analysis of human movement. Copyright 1998 Elsevier Science B.V.

Journal Article↗