Iranian Journal of Ergonomics

Introduction: Manual load lifting is the most common and most stressful activity in manual handling of loads that imposes the highest possible amount of biomechanical pressure on the body, particularly on the spine. The present study was conducted to determine the prevalence of musculoskeletal disorders and to estimate the mechanical force exerted on the lower back in workers responsible for manual load lifting.

Material and Methods: The present cross-sectional study was conducted on 120 workers responsible for manual load lifting activities in 7 industrial settings in the city of Shiraz. The Nordic Musculoskeletal Questionnaire (NMQ) was used for determining the prevalence of musculoskeletal disorders and the 3DSSPP software was used to estimate the forces exerted on the lower back during load lifting. Data were then analyzed in SPSS-19.Findings: The results showed that lower back problems constitute the most prevalent musculoskeletal disorder (68.3%). Evaluations conducted in 3DSSPP showed that in 17.5% of the cases, compressive forces, and in 10.8% of the cases, shearing forces exerted on the L5-S1 disc were higher in the workers than the permissible levels. There were no significant differences between the rate of the prevalence of lower back pain at different levels of compressive and shearing forces exerted on the disc (p>0/05).

Results: This finding might indicate the limitations of the method used in this study for conducting a comprehensive assessment of loads exerted on the spine.

Conclusion: The prevalence of musculoskeletal disorders, in particular lower back pain, was estimated to be high among the subjects studied. The risk levels of compressive and shearing forces exceeded the permissible amount in a low percentage of the workers studied. The 3DSSPP software might have certain limitations in the assessment of the pressure exerted on the spine.

Introduction: Psychosocial factors and fatigue are significant factors in nurses’ performance. Since the relationship between psychosocial factors and fatigue has been rarely studied, the aim of this study was investigating the relationship between psychosocial work factors and fatigue among nurses.
Method: In this cross-sectional study, 270 nurses from hospitals of Urmia University of Medical Sciences randomly participated. The Job Content Questionnaire and Swedish Occupational Fatigue Inventory were used for data collection. Pearson’s correlation coefficient and Structural Equation Modeling were used for data analysis.
Results: The mean (SD) of control was 66.32 (7.36), psychological job demand 35.47 (3.68), social support 22.31 (2.64), physical job demand 15.22 (2.18), and job insecurity 8.72 (4.06). Control and social support dimensions had low levels. Moreover, psychological and physical job demand had high levels, which indicates a high stress level. According to the results, psychological and physical job demand had a significant relationship with all dimensions of fatigue (P < 0.001).
Conclusions: The majority of nurses were exposed to high levels of job stress. Among psychosocial factors, physical demand was identified as the most effective factor on fatigue. Any comprehensive interventional program regarding psychosocial work factor in order to reduce job stress and fatigue can improve health care quality and also prevent medical errors.
 

Background and Objectives: Musculoskeletal disorders are common in students and several causes may be considered for them. The aim of this study was to investigate the relationship between school furniture dimensions and trunk posture with musculoskeletal disorders in students of the sixth grade of elementary school in Karaj.
Methods: In this cross-sectional study, 346 boy students in sixth grade of elementary school in Karaj were selected. A flexible ruler was used to measure thoracic kyphosis and lumbar lordosis angles. A 50-centimeter metal ruler was used to record ergonomic and anthropometric data of the students. Spearman’s correlation test was run to analyze the collected data at the significant level of 0.05.
Results: The results showed that only 18%, 12% and 50% of desk height, seat depth and seat height measures were at normal ergonomic conditions, respectively. A negative significant correlation was observed between seat depth and total Nordic score (P<0.05).
Conclusion: It seems that school furniture dimensions in sixth grade boy students of elementary school in Karaj were not in acceptable condition. So, we suggest that ergonomics standardization of school furniture should be considered to prevent its possible consequences.