Predicting Forearm Physical Exposures During Computer Work Using Self-Reports, Software-Recorded Computer Usage Patterns, and Anthropometric and Workstation Measurements (original) (raw)
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Safety Science, 2010
Occupational injuries pose a major problem in workplaces where computers are widely used. Intensive, repetitive and long period computer use results in costly health problems (direct cost), and lost productivity (indirect cost). Yet, the effect of musculoskeletal discomfort and their frequencies associated with the use of computers have not received considerable attention. This paper presents the findings of a risk assessment model through a scientific research to determine the effect of discomfort factors that contribute to musculoskeletal disorders resulting from intensive use of computers in the workplaces. In this context a questionnaire was given to 130 intensive computer users working in the university sector. A list of significant predictor variables for musculoskeletal disorders was developed to assess and analyze workplace ergonomics, worker attitudes and experiences on computer keyboard and mouse. The main focus of the current research is to seek and provide evidence that symptoms of musculoskeletal discomfort and the frequency of these symptoms are significant in the development of work-related musculoskeletal disorders (WRMSDs). This study provides the evidence that, ache and pain are the most common types of discomforts in all body regions. The discomforts were more pronounced at neck, shoulder, upper back, hand/wrist, and lower back regions. The risk factors determined by the risk assessment model were validated through ANOVA of the sEMG records for the control and test groups. The findings indicated that for each test group respondent, the mean musculoskeletal strain experienced differs in time, but the same is not true for the control group.
American Journal of Industrial Medicine, 2002
Background A prospective study of computer users was performed to determine the occurrence of and evaluate risk factors for neck or shoulder (N/S) and hand or arm (H/A) musculoskeletal symptoms (MSS) and disorders (MSD). Methods Individuals (n 632) newly hired into jobs requiring ! 15 hr/week of computer use were followed for up to 3 years. At study entry, workstation dimensions and worker postures were measured and medical and psychosocial risk factors were assessed. Daily diaries were used to document work practices and incident MSS. Those reporting MSS were examined for speci®c MSD. Incidence rates of MSS and MSD were estimated with survival analysis. Cox regression models were used to evaluate associations between participant characteristics at entry and MSS and MSD.
Different computer tasks affect the exposure of the upper extremity to biomechanical risk factors
Ergonomics, 2006
In order to determine differences in biomechanical risk factors across computer tasks, a repeated measures laboratory experiment was completed with 30 touch-typing adults (15 females and 15 males). The participants completed five different computer tasks: typing text, completing an htmlbased form with text fields, editing text within a document, sorting and resizing objects in a graphics task and browsing and navigating a series of intranet web pages. Electrogoniometers and inclinometers measured wrist and upper arm postures, surface electromyography measured muscle activity of four forearm muscles and three shoulder muscles and a force platform under the keyboard and force-sensing computer mouse measured applied forces. Keyboard-intensive tasks were associated with less neutral wrist postures, larger wrist velocities and accelerations and larger dynamic forearm muscle activity. Mouse-intensive tasks (graphics and intranet web page browsing) were associated with less neutral shoulder postures and less variability in forearm muscle activity. Tasks containing a mixture of mouse and keyboard use (form completion and text editing) were associated with higher shoulder muscle activity, larger range of motion and larger velocities and accelerations of the upper arm. Comparing different types of computer work demonstrates that mouse use is prevalent in most computer tasks and is associated with more constrained and non-neutral postures of the wrist and shoulder compared to keyboarding.
Journal of Electromyography and …, 2004
Reports in the scientific literature and lay press have suggested that computer users are at increased risk of upper extremity musculoskeletal disorders (MSDs). Early studies often found elevated rates of MSD outcomes among keyboard users when compared to non-users. Attention soon focused on specific aspects of keyboard work that might be responsible for the observed rate increase. In this review, the epidemiological evidence examining associations between MSD outcomes and computer user posture and keyboard use intensity (hours of computer use per day or per week) are examined.
Musculoskeletal symptoms and duration of computer and mouse use
International Journal of Industrial Ergonomics, 2002
The primary aim was to study associations between duration of computer and mouse use and musculoskeletal symptoms among computer users. A questionnaire was delivered to 5033 employees in 11 Danish companies and institutions and 3475 subjects responded (69%). Logistic regression analyses on 2579 full-time working employees showed that working almost the whole working day with a computer was associated with neck symptoms (OR=1.92, CI: 1.21-3.02) and shoulder symptoms (OR=1.83, CI: 1.13-2.95) among women and hand symptoms (OR=2.76, CI: 1.51-5.06) among men. These odds ratios were adjusted for psychosocial factors. Among respondents working almost all of their work time with a computer the gender and age-adjusted odds ratio for mouse use more than half of the work time was 1.68 (CI: 1.22-2.31) for hand/wrist symptoms. Call center and data entry workers experienced the lowest possibilities for development at work. All work tasks involving computer use, except computer maintenance, were characterised by a higher frequency of movements than desk work without using a computer. Call center work was characterised by the highest level of repetitiveness as both work tasks and movements were perceived as repetitive.
BMC musculoskeletal disorders, 2014
Due to difficulties in performing direct measurements as an exposure assessment technique, evidence supporting an association between physical exposures such as neck and shoulder muscle activities and postures and musculoskeletal disorders during computer use is limited. Alternative exposure assessment techniques are needed. We predicted the median and range of amplitude (90th-10th percentiles) of trapezius muscle activity and the median and range of motion (90th-10th percentiles) of shoulder, head, neck, and torso postures based on two sets of parameters: the distribution of keyboard/mouse/idle activities only ("task-based" predictions), and a comprehensive set of task, questionnaire, workstation, and anthropometric parameters ("expanded model" predictions). We compared the task-based and expanded model predictions based on R2 values, root mean squared (RMS) errors, and relative RMS errors calculated compared to direct measurements. The expanded model prediction...