Are perceived muscle tension, electromyographic hyperactivity and personality traits correlated in the fibromyalgia syndrome?

The study was performed to investigate the relationship between perceived muscle tension and electromyographic hyperactivity and to what extent electromyographic (EMG) hyperactivity relates to personality traits in fibromyalgics. Thirty-six females with fibromyalgia performed isokinetic maximal forward flexions of the shoulder combined with surface EMG recordings of the trapezius and infraspinatus muscles. Signal amplitude ratio and peak torque were calculated in the initial and endurance test phases.

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.

Chronic pain and difficulty in relaxing postural muscles in patients with fibromyalgia and chronic whiplash associated disorders.

Objective: To investigate if muscle tension according to the surface electromyogram (EMG) of the shoulder flexors is increased in consecutive patients with fibromyalgia (FM) or chronic whiplash associated disorders (WAD).

Methods: A total of 59 consecutive patients with FM (n = 36) or chronic WAD (n = 23) performed 100 maximal isokinetic contractions combined with surface electromyography of the trapezius and infraspinatus. A randomized group of pain-free female (n = 27) subjects served as control group.

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.

Lack of gender differences in the ability to relax between repetitive maximum isokinetic shoulder forward flexions: a population-based study among northern Swedes.

The aim of the present study was to analyse the effects of gender and age in a population-based sample of clinically healthy subjects on: (1) strength, endurance and perception of fatigue, (2) mean frequency (MNF) of the electromyogram (EMG), and (3) the ability to relax between active contractions (signal amplitude ratio; SAR) of the surface EMG of an isokinetic shoulder forward flexion test. With this aim we have analysed aspects of the validity of MNF as an indicator of fatigue, using peak torque as a criterion variable. The subjects were 27 men and 28 women (age range: 20-60 years), who were obtained by random sample from the official census lists (participation rate: 66%).

The influences of muscle fibre proportions and areas upon EMG during maximal dynamic knee extensions.

This study is an investigation of the relationship between muscle morphology and surface electromyographic (EMG) parameters [mean frequency of the power spectrum (MNF), signal amplitude (root mean square, RMS) and the signal amplitude ratio (SAR; i.e. the ratio between the RMS level during the passive part of the contraction cycle and the RMS level during the active part of the contraction cycle)] during 100 maximal dynamic knee extensions at 90 degrees.

Reproducibility of surface EMG variables and peak torque during three sets of ten dynamic contractions.

The interpretation of the electromyogram (EMG) of dynamic contractions might be difficult because the movement per se introduces additional factors that could affect its characteristics. There is a lack of studies concerning the reproducibility of surface EMG registrations during dynamic contractions. The aim was to investigate the during-the-day reproducibility (using intra-class correlation; ICC) of the peak torque (PT) and the EMG variables (without removing the electrodes) of dynamic contractions.

Reproducibility of surface EMG during dynamic shoulder forward flexions: a study of clinically healthy subjects.

There is a shortage of studies concerning the reproducibility of surface electromyography (EMG) during dynamic contractions. The movement per se introduces factors that could have the potential to affect the characteristics of the electromyogram. The aim of this study was to investigate the during-the-day reproducibility (using intra-class coefficient, ICC) of the peak torque (PT) and the EMG variables (without removing electrodes) of dynamic shoulder forward flexions.

Worsening of neck and shoulder complaints in humans are correlated with frequency parameters of electromyogram recorded 1-year earlier.

The aim was to investigate whether output and electromyogram (EMG) variables obtained from an isokinetic endurance test of the shoulder flexor muscles of 23 women with neck and shoulder problems in a car and truck industry correlated with improvement or worsening of complaints 1 year later. Each subject performed 100 maximal isokinetic shoulder forward flexions at 60 degrees x s(-1). Surface EMG of the trapezius, deltoid, biceps brachii and infraspinatus muscles and mechanical output (peak torque) were determined for each contraction.

One-year reproducibility and stability of the signal amplitude ratio and other variables of the electromyogram: test-retest of a shoulder forward flexion test in female workers with neck and shoulder problems.

We have studied 23 women with neck and shoulder problems in a car factory with a 1-year interval. Our main aim was to investigate the reproducibility and stability of the tension pattern. In addition, the mean frequency (MNF) of the power spectrum and the signal amplitude (RMS) of the surface electromyograph (EMG) of the trapezius, deltoid and infraspinatus muscles and mechanical output were determined throughout 100 maximal isokinetic shoulder forward flexions.

Effect of a general fitness program on musculoskeletal symptoms, clinical status, physiological capacity, and perceived work environment among home care service personnel.

The aim of the present controlled study was to evaluate the effect of a general fitness program, performed by an occupational health service, using pre-post assessment for a number of different outcome measures. A total of 160 employees working in the central home care service district of Umeå, Sweden were asked to participate in a program of a 1-year long exercise program. Of the 160 selected, 54 subjects declined to participate and nine subjects were rejected after a medical check up.

Endurance training in patients with multiple sclerosis: five case studies.

Background And Purpose: The purpose of this report is to describe how patients with multiple sclerosis increased the isokinetic peak torque of their knee flexors and perceived well-being after an endurance training program.

Subjects And Methods: Five patients trained for 4 to 6 weeks using an endurance program for the lower extremities. Before and after training, the subjects performed 50 repeated maximum knee flexions, with simultaneous recording of surface electromyographic activity of two knee flexors, on 3 separate days using an isokinetic dynamometer.

Factors interacting with perceived work-related complaints in the musculoskeletal system among home care service personnel. An explorative multivariate study.

The interrelationships between reported complaints, certain sociodemographic data and ergonomic, physical and psychosocial aspects of the work-environment were investigated in a cross-sectional study of home care service personnel using a questionnaire. Ninety-seven out of 160 randomly selected women took part in pre-tests (presented here), post-tests and one year exercise program. Significant correlations existed between musculoskeletal complaints, other (somatic and psychosomatic) symptoms and anxiety/threat for differently, mainly work-related negative changes.

The temporal occurrence of the mean power frequency shift of the electromyogram during maximum prolonged dynamic and static working cycles.

The study investigated the temporal occurrence of the mean power frequency shift (MPF) of the EMG during prolonged (dynamic and static) working cycles. Ten healthy subjects took part in the experiment. The experimental protocol required each subject to first complete 70 maximum isokinetic knee extensions at 90 degrees s-1).

Muscle endurance, muscle tension and personality traits in patients with muscle or joint pain--a pilot study.

Objective: To investigate the relationships between personality traits, depressive symptomatology and continuous muscle tension.

Methods: These were investigated by means of a visual analog scale and the presence of continuous muscle tension during repeated isokinetic shoulder flexions in patients with muscle or joint pain and controls.

Results: A significantly higher level of muscle tension between contractions was found in the patient groups in painful muscles.

The CIO and the medical informaticist: alliance for progress.

To achieve the full potential of information technology, health care institutions must overcome organizational and political barriers that often overshadow scientific and technical barriers. The time has come for an alliance between the Chief Information Officer (CIO) and medical informatics specialists, or informaticists. Organizations that successfully accomplish this alliance will position themselves to take advantage of the enormous potential of information technology to manage today's cost-quality pressures.

Mechanical performance, level of continuous contraction and muscle pain symptoms in home care personnel.

The interrelationships between reported complaints, clinical status, mechanical performance and EMG pattern of the shoulder flexors and the knee extensors, respectively, during maximum dynamic contractions were investigated. A group of 97 randomly selected women employed in the home care service participated. Those who reported complaints had more clinical findings, such as reduced mobility, tender points and muscle tightness, than non-complainers.

Muscle performance, electromyography and fibre type composition in fibromyalgia and work-related myalgia.

Muscle performance and fibre type composition were investigated in women with fibromyalgia, work-related trapezius myalgia and healthy volunteers. Each subject performed 100 repetitive shoulder flexions using an isokinetic dynamometer during simultaneous registration of surface electromyography. A biopsy from the trapezius muscle was obtained.

Muscular fatigue during repeated isokinetic shoulder forward flexions in young females.

Peak torque, work, mean power and electromyographic (EMG) activity were recorded for each of 150 repeated isokinetic maximal shoulder flexions (45 degrees-90 degrees) in 23 healthy females. From the EMG signals of trapezius, deltoid, infraspinatus and biceps brachii the mean power frequency and the signal amplitude were determined in real time. The mechanical output showed a steep decrease during the first 40 contractions, followed by a plateau maintained until the end.

The relationship between contraction and relaxation during fatiguing isokinetic shoulder flexions. An electromyographic study.

Knowledge of the strength, endurance and coordination of the shoulder muscles during dynamic contractions in healthy women would contribute to the understanding of symptoms in that part of the body in patients with myalgia. Twenty clinically healthy women performed single maximal forward shoulder flexions at four different angular velocities (0.57-3.