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At least 1,261 records · Page 70Linked to original sources
PubMed1992

[The effectiveness of physical therapy techniques. Possibilities of electromyography evaluation].

The purpose of this study is to verify the efficiency of selected physiotherapeutic techniques. EMG analysis with surface electrodes was performed in order to obtain sufficient data about the process of local strain. Furthermore, the local strain of the muscles surrounding a healthy knee is compared with the local strain of muscles after a knee injury (ACL-rupture) with resultant atrophy. The results prove modifications of progress and amplitudes of local strain and of coordination affected by atrophy/non-atrophy. On account of the first results additional research is recommended to investigate the specific aims of the different techniques.

Anterior Cruciate Ligament↗
PubMed1996

[Electromyography studies of surgically managed knee ligament ruptures. A retrospective analysis of defined injury patterns].

In 52 patients (5 groups, average age 32.8 years) with operative treatment of knee ligament injuries cutaneous electromyograms (EMG) under dynamic and isometric conditions (100 N, 200 N, 300 N) were performed in an average of 61.2 weeks postoperatively. The subgroups consisted of 13 patients with operative reconstruction of the anterior cruciate ligament (ACL), 12 after reconstruction of the medial collateral ligament (MCL), 21 after combined ACL and MCL reconstruction and 6 patients with autologous or alloplastic ligament replacement, respectively. The control group consisted of seventeen young adults without a history of knee joint injuries. The intensified and filtered analogous signals of 8 investigated thigh muscles were digitalized and analysed with help of a specially developed computer program. In summary, group specific EMG-criteria reveal distinct ligamentomuscular inhibitory reflexes and, vice versa, EMG activities of thigh muscles may indicate tendencies for group specific criterion after operatively treated knee ligament injuries.

Adult↗
PubMed1997

[Electromyography studies for objective assessment of loss of function of the lateral pterygoid muscles after dislocation fractures of the mandibular processes].

The aim of treatment for luxation fractures of the mandibular articular processes is not only complete anatomical restitution but also restoration of the mobility. In a retrospective study on 242 patients after operative and conservative treatment, it was possible to demonstrate that there are no correlations between fragment position and functional result. Functional restitution was observed after conservative treatment in 65% of cases and after operative treatment in 57%. In order to establish the causes for dysfunction of the lateral pterygoid muscle an electromyographical technique was developed to dissipate the action potentials of the muscle. Another retrospective study, performed in 23 patients with dysfunction of the mandible revealed loss of activity of the lateral pterygoid muscle after fracture treatment, independent of the treatment method, in 11.5% of cases (two patients). Without any connection to the treatment method, the remaining results permit to conclude that there are preoperative neurological defects. Therefore the pre- and posttherapeutic functions of muscles and nerves were investigated in a prospective study on 18 patients. Before the treatment 16.6% of the patients (n = 3) showed defects of the lateral pterygoid nerve with a resulting loss of muscle function. According to the findings, residual dysfunction of the lateral pterygoid muscle is determined by the extend of the traumatic nerve injury, independent of the treatment method. In the case of axonal defects of the pterygoid nerve, there can be no expectation of a restitutio ad integrum after the operative fragment position.

Adolescent↗
PubMed2005

[Identification of possible cognizance parameters of "mimic disintegration" in schizophrenia using facial electromyography].

UNLABELLED: The aim of this study was to identify signs of "mimic disintegration" in schizophrenics using a facial electromyographic (EMG) method. We compared a group of 20 unmedicated schizophrenics with a group of 20 healthy subjects, measuring the activity of three joy-relevant facial muscles (zygomaticus major, orbicularis oculi, levator labii superioris) and two nonjoy-relevant facial muscles (frontalis, corrugator supercilii) as control muscles during two consecutive presentations of an erotic slide from the International Affective Picture System. RESULT: Schizophrenics show significantly less activity of joy-relevant facial muscles and a lower smile frequency than healthy subjects. Two signs of mimic disintegration" could be identified: 1. undefined mimic reactions and 2. lack of mimic consistency. CONCLUSION: Facial EMG is a state-of-the-art method for analyzing possible signs of mimic disintegration as described by Heimann and Spoerri. We suggest further examination of the two mimic disintegration signs regarding other emotions, necessarily including more facial muscles in the testing.

Adult↗
PubMed1997

[Electromyography of the sphincter vesicae externus muscle. Technique, indications and outcome].

Electrophysiological examinations provide important findings for the clarification of urogenital dysfunctions. A routine electromyogram (EMG) of the external anal sphincter is used together with stimulation of the pudendal nerve to determine lesions of the somatomotor tract. An alternative is the electromyographical examination of the external vesical sphincter. This special method requires more time and sufficient experience. We see an indication for EMG of the voluntary vesical sphincter in urogenital dysfunctions that cannot be sufficiently differentiated with EMG of the external anal sphincter and also in disturbances that selectively affect the external vesical sphincter.

Electromyography↗
PubMed1997

[Functional electromyography analysis of radial replacement operation].

The aim of this electromyographic study was to evaluate the functional result of tendon transfers for radial palsy. Eighteen patients were compared to 16 healthy volunteers. The intramuscular emg of four muscles was recorded in parallel during extension-flexion movements of the wrist and fingers. The data were stored on FM tape and evaluated off-line. Contrary to expectations, transferred flexor muscles revealed only part of their overall emg activity during extension. Therefore, an "extensor quota" (EQ) was calculated for each muscle. It reflects its emg activity during extension as part of its entire emg activity. In non-transferred flexors EQ was low (11-27%). High EQ values (69-91%) were seen in genuine extensors of healthy persons. In only 6 of 18 patients did transferred flexors show an EQ equivalent to genuine extensors (> or = 69%). Best functional results were seen in transferred flexor carpi ulnaris (median EQ 68%). The EQ of transferred pronator teres was low (median 18%) and minor to flexor carpi ulnaris in each patient (P < 0.05). It is concluded that in cases of radial palsy, pronator teres is not suitable for replacing extensor muscles. Superficial flexors of the fingers, however, work in synergy with extensors of the wrist. According to the la reflex connections involved, these muscles should be a good choice for regaining extension of the wrist.

Brachial Plexus↗
PubMed2006

Study on three-dimensional kinematics and electromyography of ACL deficient knee participants wearing a functional knee brace during running.

This investigation examined the muscular activity and 3D knee joint kinematic changes of anterior cruciate ligament-deficient (ACLD) participants in the involved leg under bracing condition during running. Different adaptation strategies have been found between patients who can cope with the injury and patients who cannot. One of the expected changes can be the muscle activation characteristic of the injured knee during strenuous activity with and without a functional knee brace. Three-dimensional kinematic and electromyographical (EMG) data were collected from 11 participants for 10 consecutive gait cycles during running on a treadmill under both braced and unbraced conditions. Participants were administered the "Knee Outcome Survey Activities of Daily Living Scale" to distinguish functional and non-functional candidates. No significant differences on 3D kinematics and EMG data were noted between functional and non-functional participants, thus data analysis focused on comparisons of bracing conditions for one combined group. Bracing significantly reduced total range of motion in the frontal and transverse planes (P<0.05). Muscle activity at heel-strike showed a consistent trend to increase for the hamstrings and decrease for the quadriceps under the braced condition when compared to the unbraced condition. Our findings indicate that bracing the ACLD knee alters the kinematics of the injured leg while running. Tendencies toward reductions in quadriceps and increases in hamstrings activity at heel-strike indicate that bracing might have resulted in added stability of the injured knee. The adaptations to bracing found in this preliminary study further support the potential mechanical and proprioceptive contributions of the functional knee brace to protect the ACLD knee.

Adolescent↗
PubMed1998

Transrectal ultrasonography: relationship with anorectal manometry, electromyography and sensitivity tests in irritable bowel syndrome.

Irritable bowel syndrome is the most frequently diagnosed disorder in gastroenterology. It has been demonstrated with specialized motility studies that these patients compared to healthy subjects show changes in rectoanal electrical and mechanical activity and in rectoanal sensitivity. However, until now no report has been published on morphological alterations in the rectum or the internal anal sphincter. Twenty-five consecutive patients with irritable bowel syndrome (mean age 32, range 17-47 years; 24 females) were evaluated prospectively by transrectal ultrasonography, rectal sensitivity studies, and recordings of both electrical and mechanical activity of the distal rectum and internal anal sphincter during a 2-h inter-digestive period. Ten healthy volunteers (mean age 34.5, range 19-50 years) served as a control group. Paired and non-paired Student's two-tailed t test and linear regression analysis were used. It was shown that muscle thickness of the rectum during rest (4.7 +/- 0.1 mm) was correlated neither with its rectal spike amplitude (0.73 +/- 0.1 mV) nor with rectal spike frequency (17.06 +/- 3.6 spike/2 h). In addition, the diameter of the internal anal sphincter (1.2 +/- 0.1 mm) was correlated neither with its resting pressure, nor with frequency (17.1 +/- 3.2/2 h), duration (14.9 +/- 1.5 s), or amplitude (14.1 +/- 1.9 mmHg), of inhibition of the spontaneous rectoanal inhibitory reflex. No correlation was found between ultrasonographic parameters and rectal distension variables (r = 0.03). This study demonstrates for the first time morphological anorectal changes in patients with irritable bowel syndrome compared to healthy subjects, in addition to showing that morphological changes are independent of physiological ones. Therefore both transrectal ultrasonography to determine anorectal morphology and electromanometry to assess anorectal function are important measures in the evaluation of patients with irritable bowel syndrome.

Adolescent↗
PubMed2002

The relationships among peak torque, mean power output, mechanomyography, and electromyography in men and women during maximal, eccentric isokinetic muscle actions.

The purpose of the present investigation was to examine the velocity-related patterns of peak torque (PT), mean power output (MP), mechanomyographic (MMG) amplitude, and electromyographic (EMG) amplitude of the vastus lateralis (VL) muscle in men and women during maximal, eccentric isokinetic muscle actions of the leg extensors. Eight women [mean (SD)] [aged 23 (3) years] and seven men [aged 23 (2) years] volunteered for this investigation. Their PT was measured on a calibrated dynamometer at randomly ordered velocities of 30, 90, and 150 degrees x s(-1). A piezoelectric MMG recording sensor was placed between bipolar surface EMG electrodes (Ag-AgCl) over the VL muscle. Their MP was determined using the dynamometer software. The results indicated no sex-related differences (P > 0.05) for the patterns of PT, MP, MMG amplitude, or EMG amplitude across velocity. The normalized values for MP and MMG amplitude increased (P<0.05) from 30 to 150 degrees x s(-1) (30 degrees x s(-1) <90 degrees x s(-1) < 150 degrees x s(-1)), while PT and EMG amplitudes remained unchanged across velocity. The results indicated close associations between the velocity-related patterns of MP and MMG amplitudes as well as PT and EMG amplitudes. Thus, MMG amplitude reflected the velocity-related changes in muscle power output, but not torque production, while EMG amplitude reflected torque production, but not muscle power output. During maximal, eccentric isokinetic muscle actions, EMG and MMG signals provided unique information regarding the electrical and mechanical aspects of muscle strength and power.

Adult↗
PubMed2002

"Occupational backache" - surface electromyography demonstrates the advantage of an ergonomic versus a standard microscope workstation.

Musculoskeletal symptoms such as low back pain, neck pain, and tension headache are reported by up to 80% of professional personnel involved in daily microscope work. Yet, in striking contrast to the high prevalence of complaints, there is a general unawareness of this issue both in those suffering, and those ordering and designing microscopes. We intend to call attention to this underestimated work-related health hazard and to demonstrate a potential means of prevention. We obtained repeated surface electromyographic (EMG) recordings from the most strained neck, upper limb, and back muscles in 12 healthy volunteers while they were operating a near-to-ergonomic prototype workstation and a conventional microscope, respectively. Mean EMG activity was reduced in all recorded muscles when operating the ergonomic workstation compared to the standard microscope. This improvement became more distinct with sustained work, and was most pronounced in those muscles displaying the highest degree of activity while using the standard microscope. We demonstrate the usefulness of surface EMG recordings to show the advantage of an ergonomically tailored and individually adjustable microscope workstation over a standard microscope. The former allows the operator to maintain a more physiological posture, and may thus prevent the development of cumulative musculoskeletal disorders during prolonged microscope-related work.

Adult↗
PubMed2004

The acute effects of static stretching on peak torque, mean power output, electromyography, and mechanomyography.

The purpose of this study was to examine the acute effects of static stretching on peak torque (PT), the joint angle at PT, mean power output (MP), electromyographic (EMG) amplitude, and mechanomyographic (MMG) amplitude of the vastus lateralis (VL) and rectus femoris (RF) muscles during maximal, voluntary concentric isokinetic leg extensions at 60 and 240 degrees x s(-1) of the stretched and unstretched limbs. Twenty-one volunteers [mean age (SD) 21.5 (1.3) years] performed maximal, voluntary concentric isokinetic leg extensions for the dominant and non-dominant limbs at 60 and 240 degrees x s(-1). Surface EMG (muVrms) and MMG (mVrms) signals were recorded from the VL and RF muscles during the isokinetic tests. PT (Nm), the joint angle at PT, and MP (W) were calculated by a dynamometer. Following the initial isokinetic tests, the dominant leg extensors were stretched using four static stretching exercises. After the stretching, the isokinetic tests were repeated. PT decreased (P< or =0.05) from pre- to post-stretching for the stretched limb at 60 and 240 degrees x s(-1) and for the unstretched limb at 60 degrees x s(-1). EMG amplitude of the VL and RF also decreased (P< or =0.05) from pre- to post-stretching for the stretched and unstretched limbs. There were no stretching-induced changes (P>0.05) for the joint angle at PT, MP, or MMG amplitude. These findings indicated stretching-induced decreases in force production and muscle activation. The decreases in PT and EMG amplitude for the unstretched limb suggested that the stretching-induced decreases may be due to a central nervous system inhibitory mechanism.

Adult↗
PubMed2000

Mechanical performance and electromyography during repeated maximal isokinetic shoulder forward flexions in female cleaners with and without myalgia of the trapezius muscle and in healthy controls.

This cross-sectional study aimed at investigating the influence of occupational exposure to static and highly repetitive work involving the neck and shoulder muscles, myalgia of and tender point in the trapezius muscle on biomechanical output, and electromyogram (EMG) variables (mean frequency MNF, signal amplitude and ability to relax) during maximal forward flexions of the shoulder muscles. Groups of 25 cleaners suffering from chronic myalgia of the trapezius muscle, 25 cleaners free from myalgia of the trapezius muscle and 21 teachers performed 150 forward flexions using an isokinetic dynamometer. Perception of fatigue was reported and surface EMG was recorded from four muscles during the endurance test. The cleaners were stronger than the teachers. Myalgia was associated with lower levels of endurance and a high degree of perceived fatigue. The ability to relax the trapezius muscle decreased with age and was even lower in cleaners with and without myalgia. Higher MNF of the deltoid muscle but not of the trapezius muscle was found in the group suffering from myalgia compared to the groups free from myalgia. This cross-sectional study indicated that myalgia of the trapezius muscle did not influence the strength but did influence the endurance of the forward flexor muscles of cleaners. The observed decrease in the ability to relax the trapezius muscle in cleaners compared to healthy teachers might be indicative of a future insufficiency in the muscle. Prospective studies are needed to define the significance of the results presented here.

Cross-Sectional Studies↗
PubMed2001

Fibre type proportion and fibre size in trapezius muscle biopsies from cleaners with and without myalgia and its correlation with ragged red fibres, cytochrome-c-oxidase-negative fibres, biomechanical output, perception of fatigue, and surface electromyography during repetitive forward flexions.

In the literature enlarged/increased cross-sectional area (CSA) of type I muscle fibres has been reported as a morphological mark of work-related localised myalgia in the descending part of the trapezius muscle of women. These studies did not use enough subjects or lacked an adequate control group. The recording of surface electromyograms (EMG) is central to the research field of work-related myalgia. However, the influence of intrinsic muscle properties such as the effect of muscle fibre distribution upon surface EMG has to be better understood in order properly to evaluate this method as a possible diagnostic and preventive tool. This study had two aims. Firstly, it investigated the muscle fibre distribution and CSA in work-related myalgia in trapezius muscles. Secondly, the multivariate relationships among muscle morphology and histochemistry [ragged-red (RR) fibres, and cytochrome-c-oxidase-negative-fibre changes] EMG, perceived fatigue, and biomechanical output of shoulder flexions were analysed. The raw data have been presented in an earlier study. The participants in this study were 25 female cleaners with work-related myalgia of the trapezius muscle and 25 female cleaners not experiencing work-related myalgia of this muscle. The control group comprised 21 healthy female teachers who had not been exposed to highly repetitive work or static muscle work. Smaller CSA of type II fibres were found in cleaners compared to teachers. In this study the CSA of type I fibres of the trapezius muscles associated with myalgia were no greater than in muscles without myalgia. The prevalence of RR fibres together with age, fibre type proportions, CSA and working as a cleaner correlated with the ability to relax as recorded electromyographically. The relative mean frequency of the EMG of the trapezius muscle correlated with the prevalence of RR fibres, but it did not correlate with the proportions and CSA of different fibre types. Low biomechanical outputs and low signal amplitude increases of the EMG during the test were associated with high proportions of type -IIB fibres. The smaller CSA of type II fibres in cleaners might have reflected a different muscle activation pattern due to different occupational demands in cleaners than in teachers. Morphological or histopathological variables can influence the three EMG variables investigated.

Biomechanical Phenomena↗