Maria Konarska

The Effect of an Ergonomic Intervention on Musculoskeletal, Psychosocial and Visual Strain of VDT Data Entry Work: The Polish Part of the International Study

A group of routine data entry operators (female) was included in the Polish MEPS (musculoskeletal—eyestrain— psychosocial—stress) study. Before the intervention, ergonomic assessment revealed improper working conditions such as inadequate lighting, uncomfortable chairs, and lack of forearm and wrist support while medical examination revealed that trapezius muscle load along with upper arm, head and back angles were higher than advisable. Subjects complained about neck and shoulder pain, visual problems, and psychosocial conditions. The ergonomic intervention included installation of new luminaires and Venetian blinds, new chairs, repair of ventilators, and optometric corrections. The results after the intervention showed mainly improvement in chair comfort, lighting conditions, visual strain, and sitting posture. However, financial limitations did not allow satisfactory completion of the intervention leading to a mixed interpretation of the results.

Cardiovascular Stress, Energy Expenditure and Subjective Perceived Ratings of Fire Fighters During Typical Fire Suppression and Rescue Tasks

The study determined physiological and psychophysical responses to fire fighters ‘ typical activities. Self-reported assessment of the most demanding fire fighting/rescue tasks were collected with a questionnaire. Then 19 voluntary fire fighters performed 3 simulated fire fighting/rescue tasks in protective clothing. Heart rate (HR), blood pressure and energy expenditure were measured; the rating of perceived exertion (RPE) was assessed with the Borg scale. The questionnaires showed that carrying out victims, fire suppression and resuscitation were classified as heavy load; climbing stairs with a hose as moderate load. According to RPE the subjects considered their effort during ladder climbing fairly light and only somewhat harder during stair climbing and carrying out injured people. The study demonstrated that typical fire fighting/rescue tasks were associated with high energy expenditure and imposed considerable cardiovascular stress. The Borg scale appeared not suitable for assessing perceived exertion in fire fighters during simulated tasks.

A cross-country comparison of short- and long-term effects of an ergonomic intervention on musculoskeletal discomfort, eyestrain and psychosocial stress in VDT operators: selected aspects of the international project.

Three groups of data entry female visual display terminal (VDT) workers from Norway (n = 30), Poland (n = 33) and the USA (n = 29) were compared. Before intervention, the Norwegian group reported more neck pain compared with the Polish group. The Polish group reported less shoulder pain than both the U.S. and the Norwegian groups. The clinical examination documented fewer symptoms and signs of musculoskeletal illness among the Polish participants compared with the Norwegian and the U.S. groups. After intervention, the Norwegian group reported a reduction in neck pain while the U.S. group reported a reduction in shoulder pain. The Polish group reported an increase in neck, shoulder and forearm pain at follow-up compared to after intervention. The Polish group recorded higher flexion of the upper arm at follow-up parallel with an increase of pain in the upper part of the body. Visual discomfort showed variable results in the 3 countries.

Characteristics of power spectrum density function of EMG during muscle contraction below 30%MVC

The aim of the study was to quantify changes in PSDF frequency bands of the EMG signal and EMG parameters such as MF, MPF and zero crossing, with an increase in the level of muscle contractions in the range from 0.5% to 30% RMS(max) and to determine the frequency bands with the lowest dependency on RMS level so that this could be used in investigating muscle fatigue. Sixteen men, aged from 23 to 33 years old (mean 26.1), who participated in the study performed two force exertion tests. Fragments of EMG which corresponded to the levels of muscle contraction of 0.5%, 1%, 2.5%, 5%, 10%, 15%, 20%, 25%, 30% RMS(max) registered from left and right trapezius pars descendents (TP) and left and right extensor digitorum superficialis (ED) muscles were selected for analysis. The analysis included changes in standard parameters of the EMG signal and changes in PSDF frequency bands, which occurred across muscle contraction levels. To analyze changes in PSDF across the level of muscle contraction, the spectrum was divided into six frequency bandwidths. The analysis of parameters focused on the differences in those parameters between the analyzed muscles, at different levels of muscle contraction. The study revealed that, at muscle contraction levels below 5% RMSmax, contraction level influences standard parameters of the EMG signal and that at such levels of muscle contraction every change in muscle contraction level (recruitment of additional MUs) is reflected in PSDF. The frequency band with the lowest dependency on contraction level was 76-140 Hz for which in both muscles no contraction level effect was detected for contraction levels above 5% RMS(max). The reproducibility of the results was very high, since the observations in of the left and right muscles were almost equal. The other factor, which strongly influences PSDF of the EMG signal, is probably the examined muscle structure (muscle morphology, size, function, subcutaneous layer, cross talk). It seems that low frequency bands up to 25 Hz are especially feasible for type of muscle.

The Effect of an Ergonomic Intervention on Musculoskeletal, Psychosocial and Visual Strain of VDT Entry Work: Organization and Methodology of the International Study

This special issue of the International Journal of Occupational Safety and Ergonomics (JOSE) reports the results from an extensive multinational and multidisciplinary collaborative investigation of the impacts on visual display terminal (VDT) work of musculoskeletal, visual, ergonomic, and psychosocial factors. For brevity, this effort has been referred to as the MEPS project (musculoskeletal—eyestrain—psychosocial—stress). This paper lays out the basic methodological structure of the study. The study was conducted in 4 countries utilizing VDT data entry workers as the primary subject population. A battery of objective and subject assessment measures, including muscle load, visual function, physical and visual strain, postural, ergonomic and psychosocial factors, were assessed at 3 different points in time. A pre-test was given prior to an ergonomic intervention. Two post-tests were given 1 month and 1 year after the ergonomic intervention.

Heart Rate Variability and Motion Sickness During Forklift Simulator Driving

The goal of the study was to determine the effect of a 1-h hour long forklift truck virtual simulator driving on the mechanism of autonomic heart rate (HR) regulation in operators. The participants were divided into 2 subgroups: subjects with no definite inclination to motion sickness (group A) and subjects with a definite inclination to motion sickness (group B). Holter monitoring of electrocardiogram (ECG) signal was carried out in all subjects during the virtual simulator driving. For 12 consecutive epochs of ECG signal, HR variability analysis was conducted in time and frequency domains. In subjects with a definite inclination to motion sickness after ~30 min of the driving, changes in parameter values were found indicating an increase in sympathetic and parasympathetic activity with parasympathetic dominance.

Self-perceived quality of life of people with physical disabilities and labour force participation.

The aim of this study was to assess self-perceived quality of life of people with physical disabilities from the perspective of work. The following tools were used in the study: a personal questionnaire, an SF-36v2 questionnaire, an I-E Scale at Work and a Polish adaptation of the Ferrans and Powers Quality of Life Index. The study involved 426 disabled persons aged 18–65. It demonstrated that quality of life depends, to a large extent, on factors such as age and labour force participation. Duration of looking for work had a significant influence on the satisfaction from the psychological perspective and on the perception of general health. For the respondents who were unemployed and not looking for work, quality of life decreased with increased duration of professional inactivity.

Job Strain, Overtime, Life Style, and Cardiovascular Risk in Managers and Physical Workers

The purpose of the study was to determine the relation between overtime, job strain and life style, and cardiovascular risk (CVR) in 97 managers and 98 physical workers. CVR was measured with the Framingham method. Information about job strain, overtime, life style and extra-occupational activities was obtained with a self-administered questionnaire. The results showed that both groups had a similar, medium-level job stress. Being a manager and having extra-occupational activities (self-education) were significantly related with CVR (p = .000, p = .035, respectively), whereas other factors that were analysed (i.e., physical work and overtime) were not. The managers were older than the physical workers; that may be why the factor of being a manager was significantly related to CVR. The extra-occupational activities connected with improving workersʼ skills may play an important role in the development of workersʼ overload and an increase in CVR.

Coronary Heart Disease Risk Factors and Cardiovascular Risk in Physical Workers and Managers

This study aimed to assess the incidence of coronary heart disease (CHD) risk factors and cardiovascular risk in physical workers and managers in Poland. There were 232 male subjects: 123 managers (48.9 ± 11.2 years old) and 109 physical workers (37.5 ± 11.1 years old). The family history of CHD was recorded and anthropometric and biochemical indices, i.e., body mass index, visceral obesity index, blood pressure, glucose, total cholesterol, fibrinogen, HDL (high density lipoprotein), LDL (low density lipoprotein) and triglycerides were measured. Cardiovascular risk was assessed with the Systematic Coronary Risk Evaluation (SCORE) table system. The factors that turned out to be the most common in the managers were obesity, hypertension, and elevated levels of blood glucose and LDL, whereas cigarette smoking, premature CHD in the family and a high level of fibrinogen were more common in physical workers. Very high cardiovascular risk was found in 35% of managers and in 16% of physical workers.

Physical Capacity of Occupationally Active Population and Capability to Perform Physical Work

The aim of this study was to determine what proportion of occupationally active Poles have working capacity that enables them to tolerate hard and very hard physical work. For this purpose physical capacity of 1188 occupationally active subjects (524 women and 664 men), aged 18–64 years was examined. Their maximal oxygen consumption (VO2max) was determined indirectly on the basis of their heart rate during an incremental exercise test on a bicycle ergometer. It was found that hard occupational physical work was an excessive load for almost 40% of men and women. This paper discusses how this load should be decreased with planned, appropriately long rest breaks. The percentage of persons for whom their hard physical work becomes an excessive load increases with age to such a degree that a new assessment of individual capability for such work is recommended for persons over 40 years old.