Ergonomics evaluation of a government office building

An ergonomics team from the US Army Center for Health Promotion and Preventive medicine evaluated 465 video display terminal (VDT) workstations in a Government office building over an 18-day period. Each workstation evaluation involved an assessment of the worker, the chair, the desk, the keyboard, the pointing device, the monitor, and the office environmental conditions. The team also collected worker pain and injury information. The problems seen during the evaluation were characteristic of most office environments where VDT workstation furniture was purchased before the advent of mouse-driven software. The majority of furniture evaluated was not designed to meet the demands of intensive mouse use for prolonged periods of time. Much of the workstation furniture was not adjustable, chairs lacked adequate back support, and workers assumed non-neutral postures. As a result, more than 35% of the workers evaluated complained of on-the-job pain. New office furniture that is adjustable, adequate desk space and storage space were among the solutions recommended by the ergonomics team.     

The effects of workstation changes and behavioral interventions on safe typing postures in an office

The purpose of the present study was to determine the effectiveness of an ergonomic and behavioral safety intervention for improving participants' safe typing postures in a library office setting. A single-subject multiple baseline design across five participants was employed to evaluate the effects of the four independent variables (workstation adjustment, equipment trial (rollermouse mouse alternative), peer observations, and graphic feedback). Six participant postures were observed repeatedly while participants worked at their workstations throughout the study. Each of the interventions resulted in improvements in safety for more than one posture compared to the previous phase. Results of the study indicate that a comprehensive ergonomic program that includes a workstation adjustment and a behavioral safety approach may be helpful to produce maximum improvements in employees' safe ergonomic postures.     

Multi dimensional system for evaluating preventive program for upper extremity disorders among computer operators

Typing is associated with musculoskeletal complaints (MSCs), caused by multiple risk factors. Although a wide variety of ergonomic intervention programs were conducted to reduce risk factors and MSC's, only few of them were found evidence based. This study aimed to test the efficacy of a workplace intervention in reducing MSC's among computer workers. 66 computer workers were assigned randomly to one of three intervention programs: ergonomic intervention including biofeedback, intervention without biofeedback and control group without intervention. The efficacy was tested by advanced assessment including; pain location and severity, posture at work, upper extremity 3D kinematics, muscle activity and psychosocial status. Working hypothesis; significant score differences will be found between the study groups which underwent ergonomic intervention and the control group on the following measures: pain complaints, upper extremity kinematics, muscle activity and psychosocial status. Significant differences were found between pre and post intervention and between research groups and the control group in pain, posture and motion. The ergonomic intervention with biofeedback had no unique contribution in comparison to other interventions. In conclusion; the proposed intervention program was found efficient for reducing pain among computer workers.     

Health behavior change among office workers: an exploratory study to prevent repetitive strain injuries

The purpose of this evidence-based study is to investigate the impact of a multi-component intervention on health behavior change among office/computer workers in preventing repetitive strain injuries. Forty office workers employed in an administrative office in Michigan participated in this project. The subjects completed a comprehensive questionnaire at three different times in 1994 and 1995. The intervention took place between time 2 and time 3 and included posters, e-mail tips, mini-workshops, and activities of a Wellness Ergonomic Team. A theoretical model was tested to identify factors influencing healthy behaviors. Study findings revealed positive behavior change for 62% of the participants. The factors most strongly related to health behavior change appear to be self-efficacy, the intention to change one's behavior, and perceived health status. Better understanding of health behavior change coupled with ergonomic modifications is a significant step toward the prevention of repetitive strain injuries resulting from computer use.     

Prevention of musculoskeletal disorders (MSDs) in office work: a case study

Twelve recently built office work stations, where jobs imply continued use of information and communication technologies, were analyzed for ergonomic risk factors. Based on a literature review of ergonomic recommendations for computer and general office work, a checklist was devised for assistance in identifying inadequate ergonomic situations, a process that was informed by pain complaints information. RULA (Rapid Upper Limb Assessment) was selected to estimate the risk of MSDs, considering the criteria of applicability and appropriateness to the case studied. This method was applied by an occupational health and safety technician to the most critical job observed in the workplace. Criticality was estimated through observations aided by the systematic use of a checklist tailored to the specific office scenario. Recommendations for change were provided for implementation in all workplaces in the office, in order to improve work conditions, and guide the setup of a MSD prevention training program.     

A comprehensive work injury prevention program with clerical and office workers: phase I

The risk for the development of musculoskeletal disorders and associated conditions in clerical and office workers is well documented. The majority of work injury prevention programs for this population were single-faceted (education, workstation redesign, or task modification) and yielded both positive and negative findings. This pilot study was conducted with 16 full-time clerical and office workers at a small private college. In a randomized control trial, the intervention group received four hours of individualized training through a multi-faceted injury prevention program. Between group differences in musculoskeletal symptom frequency and intensity and perceived stress and energy levels existed, although were statistically insignificant. There was a statistically significant decrease in Lower Back ache/pain from pre to post measures for the intervention group.     

Noise analysis in professional office chairs

The noise caused by the movement of users on their chairs in the work environment may indicate structural weaknesses and risk, and still significantly reduce productivity by increasing employees stress level. By understanding the activities to be developed in a work place one may understand what should be necessary to a good development, thereafter a search for improvement of labor activity with the aim of better use of resources in the operation of product use may be done. The analysis of the incremental variation of noise in professional chairs aims to identify its origin and the time the emission of noise starts during the period of use, its development and the major causative agents. Determining the characteristics of the sound of different materials and adjustments mechanisms of the chair can determine how different materials interact with each other. The measurement of these noises in an acoustic isolated room using directional microphones, if recorded and analyzed properly makes it possible to investigate and orientate to suspect elements in order to propose solutions and identify the quality of other similar chairs. Based on the results recommendations can be established for the orientation of users, managers and people responsible for the acquisition of the products, inducing them to review the employment of materials and the choice of the processes of production. These aspects are not covered in the Brazilian ergonomics norms and standards in the use of chairs.     

The effectiveness of intervention strategies used to educate clients about prevention of upper extremity cumulative trauma disorders

The increased prevalence of work-related cumulative trauma disorders (CTDs) of the upper extremity highlights the need for effective prevention programs. This paper examines the effectiveness of different intervention strategies used to educate workers about the prevention of upper extremity CTDs. The articles reviewed include primary prevention and reinjury prevention interventions in both clinical and workplace settings. The current research findings are inconclusive. Intervention strategies may include discussion, demonstration, or practice of proper posture and body mechanics. Practice of correct techniques may not be necessary to achieve improved hand-use patterns in assembly-line workers. However, practice with intensive feedback may be necessary to achieve the best performance of hand-wrist position, but not sitting posture, in computer operators. The effects of practice on correct hand use may depend on the type of job task. Further research is needed to clarify the role of practice and feedback in CTD prevention.     

Workers' postural conditions in the charcoal production proccess based on vertical metallic cylynders

Considering the importance of posture to the workers' health in the production of charcoal, this paper presents an ergonomic research based on a biomechanical focus that aims to evaluate the posture adopted by these workers on the production of charcoal in vertical metallic cylinders. Thus, it was verified the incidence of pain and/or musculoskeletal injuries to these workers. Also, it was evaluated the weight carried by them and the positions taken in their daily tasks. Applying the Ergonomic Analysis of Labor, the data collection was done by directly observing the workers, registering images, by interviews, and posture analysis based on the OWAS method. The main results of the research show that there are postures with risks in the four levels of musculoskeletal injuries classified by OWAS, concluding that the method is imperative for ergonomic recommendations for minimization or eradication of suffering injury and worker's postural constraints.     

The effects of exercise reminder software program on office workers' perceived pain level, work performance and quality of life

In direct proportion to current technological developments, both the computer usage in the workplaces is increased and requirement of leaving the desk for an office worker in order to photocopy a document, send or receive an e-mail is decreased. Therefore, office workers stay in the same postures accompanied by long periods of keyboard usage. In recent years, with intent to reduce the incidence of work related musculoskeletal disorders several exercise reminder software programs have been developed. The purpose of this study is to evaluate the effectiveness of the exercise reminder software program on office workers' perceived pain level, work performance and quality of life. 39 healthy office workers accepted to attend the study. Participants were randomly split in to two groups, control group (n = 19) and intervention group (n = 20). Visual Analogue Scale to evaluate the perceived pain was administered all of the participants in the beginning and at the end of the study. The intervention group used the program for 10 weeks. Findings showed that the control group VAS scores remained the same, but the intervention group VAS scores decreased in a statistically significant way (p < 0.01). Results support that such exercise reminder software programs may help to reduce perceived pain among office workers. Further long term studies with more subjects are needed to describe the effects of these programs and the mechanism under these effects.     

The impact of school furniture on fourth grade children's on-task and sitting behavior in the classroom: a pilot study

Schoolchildren spend much of their day sitting in classroom furniture that is often too large or too small. To assess the impact of the size and fit of school furniture on the sitting and task behaviors of schoolchildren, 63 fourth-graders were observed while seated in 2 different sizes, types, and arrangements of furniture in their classroom. A correlated group design was used to compare the sitting and task behaviors of the students while seated in their traditional classroom furniture consisting of tables and chairs, and while sitting in smaller, appropriately sized desks and chairs, arranged in clusters and then in rows. The results indicate that the children sat better and were on task more when seated in the smaller furniture, as indicated by a significant main effect for condition, F = 51.478 (4, 330), p<0.05. There was no difference in sitting and task behaviors with the new furniture arranged in clusters compared to rows. Girls showed a slightly greater improvement compared to boys, and there was a significant correlation between better sitting positions and being on-task (r = 0.549, p<0.01). These findings indicate that students would likely benefit from sitting in smaller furniture that fits their size better.     

AGENDA CONTROL AND RECIPROCITY IN SEQUENTIAL VOTING DECISIONS

We study how reciprocity affects the extent to which a chair can exploit her control over an agenda if a committee votes sequentially on a known series of binary proposals. We show in a parsimonious laboratory experiment that committee members form vote trading coalitions favoring early proposals not only when the sequence of proposals is exogenously given, but also when a chair controls the sequence of proposals. Vote trading occurs even though chairs manipulate the agenda in their favor. Punishment for chairs exploiting agenda control is weak as chairs reciprocate support by others more frequently than nonchairs. (JEL C92, D71, D72)     

Anthropometric aspects of body seated in school

This study aimed to assess the student-furniture interface from anthropometric parameters of the sitting posture. The sample was composed of 887 students from two public schools in the State of Parana-Brazil, which attended children from 7 to 17 years of age. The data collection used anthropometric measures of the sitting position, a questionnaire containing a human body diagram for indication of discomfort areas and photographic records to verify postural and ergonomic inadequacies in classroom. The following anthropometric variables were measured: popliteal height, sacro-popliteal length, hip width, lumbar support height, and elbow and thigh height. Percentiles 5 and 95 of anthropometric variables showed differences statistically significant, with variation coefficient greater than 30%. In relation to body discomfort, the highest occurrences were recorded for ankle, knees and shoulder joints as well as for spine and buttocks. It was concluded that children use school furniture that does not meet their anthropometric standards, which favored the adoption of incorrect postures and contributed to the emergence of musculoskeletal problems that can interfere with their educational process.     

Effectiveness of an educational intervention to increase knowledge and reduce use of risky behaviors associated with cumulative trauma in office workers

OBJECTIVE: This pilot project assessed the effectiveness of an intervention to increase knowledge and reduce risky behaviors related to cumulative trauma disorders (CTD) in office workers. STUDY DESIGN: All 124 employees from the administrative offices of a health maintenance organization were invited to participate. Subjects were followed across time using an identification number. Data were collected via questionnaire in June 1994 (pretest1) (N=84), August 1994 (pretest II) (N= 63) and September 1995 (posttest) (N=40). The yearlong intervention focused on functional activities to prevent CTD. RESULTS: of chi-square analyses for the 40 subjects who completed all surveys indicated this intervention significantly increased overall knowledge of CTD (p =.002). Significant changes in self-reported hand/wrist (p =.016) and neck/shoulder (p =.003) posture were also found. CONCLUSIONS: This study is a first step in identifying effective educational interventions to increase knowledge and reduce risk factors related to CTD in office workers.     

Effects of a ball-backrest chair on the muscles associated with upper crossed syndrome when working at a VDT

This study examined the effect of a ball-backrest chair on the weakness and tightness of muscles associated with upper crossed syndrome when working at a visual display terminal (VDT). The surface electromyography (EMG) was recorded from the serratus anterior, middle trapezius, and upper trapezius muscles of 20 adults as they performed VDT work, which are known as the weakened and tightened muscles of upper crossed syndrome. The recorded signals were averaged and normalized to the mean amplitude of the EMG signal obtained during submaximal reference voluntary contractions. The significance of differences between the use of a general-purpose backrest and a ball backrest was tested by paired t-test, with the significance cutoff set at alpha=0.05. The activities of the serratus anterior and middle trapezius muscles increased and that of the upper trapezius muscle decreased when sitting in a ball-backrest chair compared to when sitting in a chair with a general-purpose backrest (p<0.05). These results indicate that the use of a ball-backrest chair reduces the risk of patients with upper crossed syndrome developing muscles soreness or injury related to overuse when working at a VDT.     

Ergonomic evaluation of the preparation of cuttings and minicuttings for eucalyptus seedling production, with the use of scissors

This study was conducted in a nursery for eucalyptus seedling production in a forest Company, located in the southern state of Bahia, Brazil. It aimed to evaluate the ergonomic conditions of the preparation of cuttings and mini-cuttings with scissors for Eucalyptus seedling production to increase well-being, satisfaction and safety and minimizing the occurrence of occupational diseases, also improving the process efficiency and final product quality. Environmental conditions, levels of noise, postures, RSI risk and physical workload were assessed. The environmental conditions complied with the recommended norms, except at certain times of day, when workers should make compensation breaks. The workers that collect minicuttings presented postures classified as normal by OWAS. On the other hand, the posture of workers dealing with cutting preparation requires corrections in a short run. The workers were subjected to moderate RSI risk due to the high degree of repeatability found. The physical workload was classified as mild, with no need for ergonomic interventions.     

Anthropometric change: implications for office ergonomics

Well-designed office workspaces require good anthropometric data in order to accommodate variability in the worker population. The recent obesity epidemic carries with it a number of anthropometric changes that have significant impact on design. We examine anthropometric change among US civilians over the last 50 years, and then examine that change in a subset of the US population--the US military--as military data sets often have more ergonomic dimensions than civilian ones. The civilian mean stature increased throughout the period 1962 to 2006 for both males and females. However, the rate of increase in mean weight was considerably faster. As a result, the male obesity rate changed from 10.7% in 1962 to 31.3% in 2006. The female change for the same period was 15.8% to 33.2%. In the Army, the proportion of obesity increased from 3.6% to 20.9%, in males. In the absence of national US ergonomic data, we demonstrate one approach to tracking civilian change in these dimensions, applying military height/weight regression equations to the civilian population estimates. This approach is useful for population monitoring but is not suitable for establishing new design limits, as regression estimates likely underestimate the change at the ends of the distribution.     

Ergonomic intervention in aonla pricking operation during preserve preparation in food processing industries

Aonla is an important Indian fruit crop with great potential for processing into various quality products. Aonla preserve making is an important economic activity in our country. The pricking methods are age old, hence a hand operated aonla pricking machine was introduced in preserve making industries to speed up the pricking task. OWAS and RULA two of the most commonly used ergonomic assessment tools were evaluated for their efficacy in the assessment pricking along with Rating of perceived exertion scale. Analysis of working posture using RULA revealed that the pricking task with existing methods i.e. fork and hand tool requires immediate investigation and changes in working posture while with machine pricking investigations and changes are required soon. The results of OWAS indicated that the posture maintained while pricking with existing methods need to be changed in future planning while with machine was acceptable. The subjective assessment revealed that machine pricking was less exerting activity as compared to the existing methods. The preserve prepared from machine pricked fruit was most acceptable among consumers. Hence, in the form of machine ergonomic intervention was brought about in preservation industries which have proved beneficial for workers in terms of their safety and productivity.     

Effects of a participatory ergonomics intervention computer workshop for university students: a pilot intervention to prevent disability in tomorrow's workers

A participatory approach was used to create a computer ergonomics workshop for college students, incorporating an instructional systems design process and adult learning inquiry perspectives. The primary objective of this participatory ergonomic pilot intervention was to involve students throughout the training design process in solving computer workstation ergonomic problems and adopting healthy computing behaviors. Students' level of participation included becoming part of the training design team, a co-facilitator, or a student trainee. A second objective was to examine the translation of an industrial office ergonomics training program into a college computer ergonomics training program. The long term goal was to reduce upper extremity symptoms and disability. The program was piloted at one private university. The three student trainees significantly increased their knowledge of computer ergonomics from 69% of test items answered correctly pre-training to 82% post-training. Trainees were also successful in conducting computer ergonomic evaluations of students' computing work areas. They achieved 100% accuracy in identifying ergonomic problems and proposing solutions in five ergonomic workstation assessments in the field. This approach was successful in creating a sense of ownership among the student developers and facilitators as reflected in their self-reports during a post-intervention debriefing. The results of this pilot study justify formal controlled trials of this intervention in university students, who will become tomorrow's workers.