Effects of neutral posture on muscle tension during computer use.
(33/527)
This study focused on developing a new approach to seated work positions was conducted on 67 office workers who use a Visual Display Terminal (VDT) as a major function of their working day. Muscle tension was measured by surface electromyography (sEMG) while participants were asked to adopt 4 selected working postures. Pain was measured before and after ergonomic intervention on the Nordic scale, which was modified for this study. Adjustable workstations were used to place participants in desired positions during the clinical testing sessions and the extended intervention period. Results indicate the effects of this ergonomic intervention may have positive effects on muscle tension and pain, significant enough to encourage employers to implement training and workstation modifications following these guidelines. (+info)
Identification of driver model parameters.
(34/527)
The paper presents a driver model, which can be used in a computer simulation of a curved ride of a car. The identification of the driver parameters consisted in a comparison of the results of computer calculations obtained for the driver-vehicle-environment model with different driver data sets with test results of the double lane-change manoeuvre (Standard No. ISO/TR 3888:1975, International Organization for Standardization [ISO], 1975) and the wind gust manoeuvre. The optimisation method allows to choose for each real driver a set of driver model parameters for which the differences between test and calculation results are smallest. The presented driver model can be used in investigating the driver-vehicle control system, which allows to adapt the car construction to the psychophysical characteristics of a driver. (+info)
Effects of Ergorest arm supports on muscle strain and wrist positions during the use of the mouse and keyboard in work with visual display units: a work site intervention.
(35/527)
The effects of Ergorest arm supports on wrist angles and musculoskeletal strain in the neck-shoulder-arm region and electrical activity in the shoulder and arm muscles were studied during typing or the use of the mouse in work with a visual display unit (VDU). Twenty-one women were randomized into 3 groups (1 arm support, 2 arm supports, and control). Measurements were carried out before and after the 6-week intervention. The wrist extension of the mouse hand, the muscle activity of the trapezius muscle, and the subjective discomfort ratings indicated that 2 arm supports were better than 1 in work with a mouse. The Ergorest arm support alleviates muscle and joint strain in VDU work when used for both arms. (+info)
Ergonomics: requirements for adjusting the height of laparoscopic operating tables.
(36/527)
BACKGROUND AND OBJECTIVES: In the last few years many new instruments and devices have been developed and introduced into the operating room (OR). A debate has been ongoing about the optimal ergonomic posture for the operating staff. From practical experience, we have learned that the operating tables cannot be adjusted adequately to allow surgeons of different stature to maintain a comfortable posture. The goal of this study was to establish the most ergonomic table height for the particular physique of the surgeon and the different types of laparoscopic instrument handles that he or she uses. METHODS: In a simulated model, two probands of different stature (50th [BS 50] and 95th [BS 95] percentile) used laparoscopic instruments with four different handle designs (shank, pistol, axial, and rod). The instruments were inserted into a board in three different angles ([IA] = 20 degrees, 30 degrees, 40 degrees). Additionally the elbow angles (EA) of the volunteers were fixed to either 90 degrees or 120 degrees. For every variable (size of surgeon and his or her elbow angle, design of handle, insertion angle of the instrument) the height of the board, as a parameter for the level of the abdominal wall of a patient with pneumoperitioneum, was measured from the floor. RESULTS: All parameters had an effect on the optimal operating table height. The lowest required operating table level was 30 cm, the highest was 60.5 cm. In laparoscopic surgery-long shafted instruments and patients with pneumoperitoneum-the tabletops are too high for over 95% of all surgeons. As skin incision and wound suture are performed the conventional way, the operating tabletop must be adjustable up to the common height of 122 cm. The maximal difference between the optimal heights of the OR-table for one volunteer using two different handles with different insertion angles of the instruments (BS 95, EA 90 degrees, IA 20 degrees, rod handle to BS 50, EA 120 degrees, IA 40 degrees, axial handle) was about 27 cm. CONCLUSION: New operating tables with a much lower adjustability are necessary to fulfill ergonomic requirements. The use of differently designed handles can hinder the ergonomic posture of the surgeon, because each handle requires a different working height. (+info)
A heart rate evaluation approach to determine cost-effectiveness an ergonomics intervention.
(37/527)
This paper describes a hear-rate methodology to determine the cost-effectiveness of an ergonomics intervention to reduce workload and improve working conditions. This is a practical approach as opposed to the energy expenditure technique that is difficult to implement in natural settings. This was a laboratory study using a large excavator cabin with devices to simulate excavation operations. Mean heart rate was used to calculate the required rest time during a shift with or without air-conditioning. The criterion for evaluation was differences in required rest time during a shift under these 2 conditions. The simplicity and objectivity of this approach invites use to solve the problem of the economic evaluation of ergonomics interventions. (+info)
Integrated estimation of the effect of physical factors on human functional state during mental work.
(38/527)
The purpose of this study was to develop a model for an integrated estimation of the functional state of the human organism (FSHO) and an integral estimation of physical factors (PF) for hygienic rating. Tests were performed twice with 3 men in 0.7-clo clothing during 4-hr mental work with 9 combinations of 4 PF: wideband noise (55- 83 dB(A)), whole-body vibration (6 Hz, a(z) = 0.2-1.8 ms(-2)), air temperature (18-30 degrees C), and illumination (1, 3, 5 lx). Thermoregulatory, cardiovascular, and psychophysiological reactions and temporary threshold of hearing (TTS2) shifts were studied. For the integral estimation of PF influence on FSHO the model F(y1,y2..........ym) = f(x1,x2,.......xn) was used, relating both FSHO and PF sets. The most important physiological parameters in creating FSHO are defined and the contribution of individual parameters of FSHO and PF is found. (+info)
A method of ergonomic workplace evaluation for assessing occupational risks at workplaces.
(39/527)
The paper discusses new trends in developing and implementing methods of workplace analysis. It presents a sample method of ergonomic workplace evaluation developed at the Poznan University of Technology. The method is a response to the industrial sector's demand for tools supporting occupational risk assessment. The authors also present opportunities and benefits of applying the method in occupational safety management systems, which have gained increasing popularity in recent years. (+info)
Grassroots ergonomics: initiating an ergonomics program utilizing participatory techniques.
(40/527)
The introduction of ergonomics programs throughout the world requires an easy to understand and inexpensive process. Participatory ergonomic intervention techniques have proven to be beneficial in the prevention of musculoskeletal disorders. The participatory approach to ergonomics has also been found to be a useful application within industrialized (developed) countries and industrially developing countries (IDCs). Grassroots Ergonomics principles utilize expertise within a workforce that focuses on participatory ergonomics interpretations of quantitative and qualitative risk and exposure assessment information that in turn results in a peer-developed ergonomics training. Regardless of the intricacy of the exposure assessment tools, workers should fully assist in gathering and analyzing data, then in identifying and implementing solutions. A coordinated and multidisciplinary application of this approach within IDCs would succeed in the creation and sharing of job-specific ergonomics training information for high physical exposure professions, such as agriculture, fishing, forestry, mining, and small-scale enterprises, to initiate ergonomics programs regionally. (+info)