Ergonomic Work Design Research Articles

Global prevalence of musculoskeletal disorders among sanitary workers: a systematic review and meta-analysis

ABSTRACT Objectives. Sanitary workers are more likely to experience musculoskeletal disorders (MSDs) due to a lack of ergonomics principles and poor job design. Thus, this systematic review and meta-analysis aimed to quantify MSDs among sanitary workers. Methods. The PRISMA and PICOS protocols were used for flow diagrams and review questions, respectively. Articles published between 2000 and 2022 were eligible. The keywords ‘(Musculoskeletal Disorders) AND (Solid waste collectors *OR Street sweepers *OR Sewage workers *OR health facilities cleaners)’ and MeSH terms were utilized. The data were analyzed using STATA version 17 with a 95% confidence interval (CI). Results. A total of 158 papers were qualified, with 26 studies from 17 countries and a total of 6586 sanitary workers. The global prevalence of MSDs among sanitation workers was 40.52% (95% CI [32.47, 48.67]; p < 0.05). It was 43.32% (95% CI [31.98, 54.68]; p < 0.05) in high-income countries and 38.58% (95% CI [26.94, 50.18]; p < 0.05) in low-income countries. By subgroup analysis, it was 45.12% (95% CI [32.57, 57.67]; p < 0.05) for solid waste collectors, which is the highest prevalence among other workers. Conclusion. Current evidence shows that sanitation workers have a higher prevalence of occupationally associated MSDs, which might be lowered by using ergonomic work design principles.

ERGONOMICS AND STRESS REDUCTION IN ORGANIZATIONS

Implementing ergonomic solutions can make employees more comfortable and increase productivity. This study focused on examining the impact of ergonomics on stress reduction in Globacom and MTN Organizations. The study adopted a survey research approach in its design. The study was made up of a sample size of 95 samples drawn from a population of 109 using the Taro Yamane formula. The study used the simple percentage, Pearson productmoment correlation, and simple regression with the aid of SPSS version 20. Findings of the study include that ergonomic work design variables have a significant impact on employee stress reduction. The Study, however, recommends that; to enhance employees well being, organization need to balance work demands, employees’ skill, and the nature of the equipment used in completing a task. The study concludes that ergonomics has an enormous impact on the performance of employees in Globacom and MTN organizations.

Extended compilation of autopsy-material measurements on lumbar ultimate compressive strength for deriving reference values in ergonomic work design: The Revised Dortmund Recommendations.

Measures of human physical capacity are required in ergonomic work design. To avoid biomechanical low-back overload, criteria are needed to differentiate load and overload. With respect to the evaluation of manual materials handling and similar physical exposures regarding potential overload, the compression component of the forces transferred via lumbar discs or vertebrae are compared with the ultimate compressive strength of lumbar-spine segments in a common biomechanical approach. As mechanical load-bearing capacity cannot be quantified directly in vivo, forces are applied to dissected spinal elements up to failure, which is interpreted as a measure of ultimate strength or tolerance to compression. Corresponding autopsy-material measurements were collected from literature and examined regarding several conditions: At the very minimum, a specimen consists of a complete vertebra or a disc including the adjacent endplates; failure is identified definitely as lumbar; compressive-force application is quasi-static; results are given as single values etc. This study continues previous collations, the latest is dated on 2001 including 25 usable out of 47 investigations totally. Currently, 66 newly discovered seemingly appropriate studies were collected via a systematic literature search, 11 of them were added for subsequent analysis. Nearly 4,000 values were compiled, 1,192 remained for analysis. Human lumbar ultimate compressive strength varies between 0.6 and 15.6 kN, mean and standard deviation are 4.84 ± 2.50 kN. For data originating from donors of specified gender and aged 20 years or more, the distributions are characterised by 6.09 ± 2.69 kN for male adults (n=305) and 3.95 ± 1.79 kN for female adults (n=205). According to a linear regression model for donors aged 20 years or more, strength significantly decreases with age: 10.43 kN minus 0.923 kN per 10 years of age for males and 7.65 kN minus 0.685 kN per decade for females. Based on these gendered age relations, the “Revised Dortmund Recommendations” were derived ranging between 5.4 kN for males aged 20 years and 2.2 kN for males of 60 years or more. The corresponding recommended limits for females amount to 4.1 and 1.8 kN, respectively. A specific safety margin was implemented for young adults up to 25 years of age as skeletal strength may not be fully developed. Due to the compression-related and biomechanical nature of this approach, other influences like shear or torsion as well as psychological or psychosocial risk factors remain unconsidered despite their undoubted importance for initiating complaints, disorders and diseases at the low-back region.

중공업 근로자의 악력 특성 분석에 관한 연구

The WMSDs are known to occur more in upper extremity than lower extremity, and such a ratio is increasing each year. The motions or repeated work requiring excessive strength beyond worker's maximum grip strength were known as a major cause of the WMSDs in upper extremity. To prevent the WMSDs in upper extremity, research on the grip strength characteristics analysis of field workers that can be used as basic data for work design and manual tool design is needed. The purpose of this study is to identify various variables affecting grip strength and is to find out the impacts of grip strength on WMSDs. This research measured the grip strength of 327 field workers at Heavy Industries, and also conducted a questionnaire survey on individual characteristics and job characteristics. As a result of analyzing grip strength, the grip strength was statistically significant (P<0.1) according to the body surface area (BSA) of the research subjects. The differences between percentile groups of grip strength were statistically significant (P<0.1) according to pain levels of hand/wrist/finger and arm/elbow. The comparison results between the average grip strength of Korean adult males and the average grip strength of the survey-targeted heavy industry workers show that the average grip strength of the heavy industry workers was higher by 9.75 kg. This study analyzed relationship between grip strength and the pain levels of hand/wrist/finger and arm/elbow, and compared the findings in this study with those of existing preceding studies. Also, this research comparatively analyzed the grip strength of Korean adult males and survey-targeted heavy industry workers. The findings of this study can be used as useful data for ergonomic work design and manual tool design to prevent WMSDs at industrial worksites, given that almost no data on the grip strength of workers in the industrial sites are found in Korea.

Dynamic Electromyography Analysis of Shoulder Muscles for One-handed Manual Material Handling

Objective: The objective of this research is to quantitatively analyze muscle activities of arm and shoulder, according to direction in various types of one-handed manual material handling, based on surface electromyography.BR Background: Workers in industrial sites frequently carry out one-handed manual material handling using arm and shoulder muscles. Therefore, chronic load and accumulated fatigue occur to arm and shoulder muscles, which becomes a main cause of upper arm and shoulder musculoskeletal disorder. The shoulder muscles have widely range of motion, and complex interactions take place among various muscles including rotator cuff muscles. In this regard, research on interactions among should muscles, according to such various dynamic motions, is required.BR Method: Ten male subjects in their 20s participated in this research. This research considered upward, downward, leftward, rightward, forward and backward directions and fourteen muscles around arm and shoulder (biceps brachii and trapezius, etc.) as independent variables. The mean muscle activity was set as the dependent variable. This research extracted 4th~7th repetition signals according to ten times of repetitive muscle contraction, and analyzed the muscle activity concerned using the envelope detection technique.BR Results: The mean muscle activity of upward direction was analyzed highly statistically significant. The reason is that the effect of gravity works to arm and shoulder muscles. Also, it is conjectured that deformation of coracoacromial ligament was caused, and its contact pressure increased, due mainly to the shoulder flexion, and therefore load was analyzed high. Muscle activity was analyzed significantly low, according to concentric ballistic motion used in the concentric contraction phase by storing elastic energy in the eccentric contraction phase with a motion to bring the weight to the front of subject’s body as to downward, leftward and backward directions. Because, elbow joint’s flexion-extension motions mainly occurred, biceps brachii was analyzed high muscle activity as the prime mover.BR Conclusion: The information on the quantitative load muscles can be applied to ergonomic work design for one-handed manual material handling to minimize muscle load.BR Application: This research has effectively identified muscle activity according to dynamic contraction by applying an envelope detection technique. The results can be used for ergonomic work design to minimize muscle load during the one-handed manual material handling, according to each direction. The research results are expected to be used for musculoskeletal disorder prevention and physiotherapy in the rehabilitation medical field, based on the muscle load of arm and shoulder in various directions.

Medical work assessment in German hospitals: a study protocol of a movement sequence analysis (MAGRO-MSA).

BackgroundMedical doctors are essential for the German public and occupational health system. They ensure the productivity of German society by enabling people to regain and recover their health. That is why the physicians’ health and hence their productivity require special attention. Musculoskeletal disorders have a high prevalence in this work area. As a consequence, movement sequences, range of motions, and body postures of physicians in the course of the working day are in focus of this research project.MethodsFor this investigation 21 male or female junior physicians of various conservative medical disciplines will be covered. Data will be collected over one working day (approx. 9 hours). The CUELA system attached to the test person’s body detects body posture and/or movements. This biomechanical measurement system ensures a locomotor and posture analysis that includes movement sequences, movement intensity, and range of motions to qualify the work tasks. For data analysis intra- and inter-professional comparisons are chosen.ConclusionsWorking movement sequence analysis of physicians by means of the CUELA system is exclusive and novel in its focus. Up to now, knowledge of the working tasks of medical doctors has only been acquired by real-time observation approaches to work activity. In addition to this method of analysis, the CUELA system is able to record quantified biomechanical data about musculoskeletal loads of ordinary working tasks. Workloads and activities of physicians can be improved by ergonomic work design to reduce musculoskeletal disorders by utilizing the data collected. The healthcare system in Germany will thus be optimized by improving medical doctors’ health. Consequently, MAGRO-MSA will also be used for other healthcare professions such as nurses and physicians assistants.

A case study of Bayesian belief networks in industrial work process design based on utility expectation and operational performance

PurposeThe primary purpose of this study is to illustrate a practical approach for industrial work process design that, in an integrative manner, captures essential concerns from different parties associated with manufacturing. It aims explicitly to incorporate utility expectation from the perspectives of operational managers, floor workers, and financial planners into the decision making process.Design/methodology/approachThrough a real industrial scenario, the case study illustrates the use of a Bayesian belief network (BBN)‐based expert system and influence diagram in work process design. What‐if analysis is performed. Statistical tests are then used to benchmark and validate the experimental results and actual data.FindingsThe results suggest that the proposed BBN framework is effective in modeling and solving the work design problem. The findings can draw meaningful insights into the adoption and capacity of BBN in the fields of ergonomics, worker health management, and performance improvement.Practical implicationsPractically, the industrial problem is to compare the new stand‐up sewing cells against the traditional sit‐down sewing layout while taking into consideration of ergonomic effect (repetitive motion injury (RMI) likelihood), floor space (SF), yield (%), and cost ($). The study illustrates the use of an expert system and influence diagram to evaluate different alternatives for ergonomic work design in production process.Social implicationsThe results of this study can potentially improve health safety management and worker ergonomics.Originality/valueThe paper is among the few systematic studies that have applied BBN and influence diagram to production ergonomics and worker health management. A methodological framework utilizing these probabilistic reasoning techniques are developed. This new framework can capture essential concerns from different parties in manufacturing.

The Relationship Between Person-Environment Fit, Control, and Strain: The Role of Ergonomic Work Design and Training

Ergonomics is an important workplace practice. Experienced stress in the workplace manifests itself in poor physical and mental health, and is associated with numerous negative personal and organizational outcomes. This study examines ergonomics and ergonomic training and their potential to reduce dysfunctional personal and work outcomes; specifically, job induced-tension and job dissatisfaction directly and through perceptions of person–environment fit and perceptions of control. Quantitative and qualitative findings indicate positive relationships between ergonomic design and ergonomic training with perceptions of person–environment fit and control. Person–environment fit and control fully mediated the relationship between training satisfaction (component of ergonomic training) and job dissatisfaction, while partially mediating the relationship between work-area design (a component of ergonomic design) and job-induced tension.