Iranian Journal of Ergonomics
Year:2017 | Volume:5 | Issue:2 |Papers Count:10

Background: Different studies around the world show that work-related musculoskeletal disorders (WMSDs) are the causes of lost time, absenteeism and disability. The purpose of this study were to investigate the prevalence rate of musculoskeletal disorders (WMSDs), evaluate their ergonomic riska aafactors and determine the effect of ergonomic intervention on awkward postures among workers of SIPA Diesel Truck manufacturing plants.Materials and methods: This interventional study (Before- after) was conducted among 130 workers of two largest truck manufacturing plants in Iran. The prevalence rate of MSDs and ergonomic risk factors were assessed by valid and reliable translated Body Map questionnaire (BM) and quick exposure check (QEC) method, respectively.Results: According to Body Map results, 87.5% of participants suffered from MSDs at least in one of their eleven body regions during last year, before study. The highest prevalence rates of MSDs were observed in lower back (51.5%) and foot (18.5%). Chi square test revealed that the prevalence rate of MSDs was more among those with higher QEC risk level (P<0.001). Results also show significant effect of ergonomic interventions on reducing the prevalence rate of MSDs and QEC risk level (P<0.001).Conclusion: This study showed that the prevalence rate of MSDs and QEC risk levels among workers studied were significantly high. So it can be mentioned that, the need for early ergonomic interventions is felt in all industrial units of theses truck manufacturing plants.

Introduction: Recent challenges related to patient safety and medical errors in healthcare, has led to a focus on increasing quality across healthcare organizations. Psychosocial work factors and fatigue have been identified as significant factors related to nurses’ performance. The relationship between psychosocial work factors and fatigue has been rarely studied. The aim of this study was investigating the relationship between psychosocial work factors and fatigue among nurses.Material and Methods: In this cross-sectional study, 270 randomly nurses from university hospitals participated. The Persian version of Job Content Questionnaire (P-JCQ) and Swedish Occupational Fatigue Inventory have used the tools for data collection. The correlation coefficient was employed to examine the relationship between job stressors scales and fatigue. Structural equation modeling was applied to fit the model Results: The mean (SD) of decision latitude 66.32 (7.36), psychological job demand 35.47 (3.68), social support 22.31 (2.64), physical job demand 15.22 (2.18), job insecurity 8.72 (4.06) were found. Decision latitude and social support dimensions had a low level, which indicates higher stress. Moreover, psychological job demand, as well as physical job demand, had a high level which indicates high stress. According to results demonstrate that psychological job demand and physical job demand have a strong association with all dimensions of fatigue (P<0.001)). Job insecurity is associated with mental (cognitive) fatigue (P<0.001). Finally, social support is associated with operational (functional) (P<0.05).Conclusion: high level of job stress was found in the study population. Physical demand was identified as the most effective factor in fatigue. Designing comprehensive intervention that accounts for psychosocial aspects of work environment especially the physical demand for decreasing stress and fatigue, can improve health care quality and also prevent medical errors.

Introduction: Application and correct interpretation of the 6 minute walk test (6MWT) in medical, therapeutic and exercise setting requires normal values of the 6 minute walk distance (6MWD). The aim of this study was to develop and cross-validation of the 6MWD prediction equation in healthy children and adolescent boys.Methods: After endorsement of validity and reliability of the 6MWT, anthropometric variables and 6MWD were measured in 391 boys (8-17 yrs) with standard methods. Pearson correlation was used to assess relationship between 6MWD with independent variables. Multiple regression analysis was used to design 6MWD prediction equation from dependent variables. Furthermore accuracy of present 6MWD prediction equation was cross-validate.Results: Significant correlation was found between 6MWD and anthropometric characteristics (p<0.001). Multiple stepwise regression reviled that age and BMI can explain %63 of the variability of 6MWD in children and adolescent boys (r2=0.627, SEE=36 m, p<0.000). When the new 6MWD prediction equation was applied in the validation group, predicted 6MWD correlated well with measured 6MWD (r=0.79, P<0.001).Conclusions: This is the first study about develop native 6MWD reference values. With application of this 6MWD prediction equation, physicians, physical therapists and fitness coaches can receive correct feedback of pharmacological, rehabilitation and exercise interventions.

Introduction: Job motivation is one of the factors factors influencing the behavior of librarians that can improve their performance. Considering that organizational culture is one of the factors influencing job motivation, the purpose of this study is to identify dimensions of organizational culture affecting job motivation of librarians in public libraries of Iran.Methods: This qualitative study was conducted using content analysis. By purposive sampling, 19 people of librarians of public libraries in 10 provinces were interviewed using depth and semi-structured interviews. After extracting the primary codes, they classifyied in 3 dimmensions and 8 components.Results: Based on data dimmensions of organizational culture affecting job motivation are: Knowledge-oriented and Capability-oriented Culture (includes: professionalism and meritocracy, professional capability, use of technology, organizational learning), independency culture (inclides: non- politicization in the library, decentralization), and participatory and motivational leadership culture (includes: participatory management, motivational management). of public libraries in Iran shows that all of them have conducted by use of existing models. In view of nature and social roles of public libraries and broad impressive factors on them, these models have limitations to assess status of organizational culture in public libraries. So it is necessary to identify dimensions and components of effective organizational culture in public libraries of Iran and then manage the organizational culture on basis of this effective culture.Conclusion: Dimensions and components of effective organizational culture resulted from this study can use as an ideal model for managing organizational culture or efforts to rule these cultural components in the public library of Iran.

Introduction: Nurses as the most important part of human resources in health service system are often faced with problems associated with shift work. The present study tests a model of the relationship between workload with physical and mental health and with of mediation of sleep quality.Methods: This cross-sectional study was done among 236 nurses working in three educational hospitals in Bojnord city. To collect data Survey of Shift workers (SOS) questionnaire was used. Structural equation modeling (SEM) through AMOS-21 and SPSS-19 software package was used for data analysis. In addition, Preacher and Hayes’ SPSS Macro program was used for testing mediation.Results: The results showed that the proposed model fit the data properly. Also workload directly affected only physical health, and the quality of sleep has a mediator role in the relationship between workload and physical and mental health.Conclusion: Sleep quality as an important variable can mediate the relationship between workload and physical and mental health in nurses. It is suggested that interventional interventions to improve the health of the staff focus on adjusting and shifting job shifts and teaching the principles of sleep hygiene to them.

Introduction: Lighting affects many non-visual functions such as Circadian Rhythm, alertness, core body temperature, hormone secretion and sleep. The aim of this study was to investigate the effects of lighting on human cognitive and mental performance in the form of a systematic review.Materials and Methods: in order to access to articles, search was conducted from databases including ISI Web of Knowledge, Scopus, PubMed and Science Direct. The search were done using the keywords "Lighting" and "Illumination" and "Cognitive Performance", "Mental Performance", Memory "", "Attention", "Concentration" by title, keyword and abstracts of articles published in databases mentioned from 2010 to 2016.Results: Lighting is affecting on human performance in three areas of Psycho-cognetive (including visual comfort, visual perception, color recognition, identification of symbols, attention, working memory, learning, reaction time and brain function), Biocognitive area (including alertness, mood, vitality, subjective feelings, motivation and well-being and quality of sleep) and the Mental workload (amount of workload, psychological stress, mental fatigue) is. The best of light is bright daylight in the morning with a short wavelength (wavelength 420-480 nm) and high intensity (1000lx) in the regulation of cognitive processes, biological (circadian rhythm) and mental.Conclusion: Lighting design should be such that in addition to comfort and visual needs, also, it should provide the non-visual and cognitive needs such as attention, alertness, mood, sleep quality and decrease mental fatigue and eventually well-bing.

Introduction: In recent years, with the progressive development of various scientific, research and industrial fields, there are musculoskeletal disorders in computer and laptop users. Musculoskeletal disorders include pain and pressure in areas such as wrists, elbows, neck and shoulders, along with The fatigue of these areas, especially back and waist pain, is common among many computer and laptop users. The purpose of this study was to design a customizable ergonomic table for use in laptops based on the anthropometric characteristics of Mazandaran medical students.Methods: 108 people including 61 males and 47 female students of Mazandaran University of Medical Sciences.10 parameters include: Knee height sitting on a chair, Eyes- elbows height, Cross-legged posture kneeling length, Cross-legged posture kneeling height, Thick thighs, Elbow rest height sitting, Shoulder - fingertip length, Abdominal depth, Hip breath, Elbow-fingertip length was measured using adjustable seating, caliper and meter. SPSS software version 20 was used to analyze the data. Then the percentiles 1 to 99 and the golden number 1.618 were used to design the table.Results: The mean age of subjects was 23 ± 3.14. Based on anthropometric characteristics, gold number, resulting percentiles and design equations, an adjustable ergonomic table was designed in three seated sitting, four-knee and Flower’s position.Conclusion: It is expected that after putting this device on the laptop the musculoskeletal disorders caused by its use will be reduced. Because of limited studies have been conducted in this area, it is suggested that more and more studies should be done in this regard.

Introduction: Scissors are essential tools in different occupations including sewing and clothes making. Improper design of fabric cutting scissors can lead to the development of musculoskeletal symptoms among users.Objective: The aim of this study was to evaluate pinch force and wrist posture while working with three designs of sewing scissors and a traditional sewing scissors.Methods: The first model had a bent-handle (to improve wrist posture), the second model had a thumb-ring that was located closer to the pivot (to reduce thumb’s abducted position and range of movement), and the original oval ring in the third model was changed to a hook-shaped handle (to reduce hand and finger discomfort). Pinch force was measured using a pinch gauge and wrist posture was measured in two anatomical planes including flexion/extension and ulnar/radial deviation using observational method.Results: The results showed significant effects of scissors design on pinch force exertions (p<0.01) and ulnar/radial deviation of the wrist (p<0.001). The lowest level of pinch force decrement between pre and post pinch force measurements was recorded for the second model (2.4%), while the highest level was recorded for the traditional model (7%). More neutral wrist postures in ulnar/radial direction (83%) were recorded for the first model compared to the other designs.Conclusions: The second scissors, which was designed to reduce thumb’s range of motion and abduction, showed some improvement in pinch force compared to the traditional model.