Journal of Health and Safety at Work

---

Introduction: Musculoskeletal disorders (MSDs) are prevalent in work settings and are associated with high rate of prevalence and costs. Musculoskeletal conditions have multifaceted nature, and occupational factors play an important role in their development. The aim of this study was to identify the risk factors of work-related musculoskeletal disorders in the working population in Iran during 2000 to 2015.
Material and Methods: Using the appropriate search terms, articles published in the journals, student thesis, and those presented at the conferences were searched through authentic English databases (Google Scholar, Scopus, PubMed) and Farsi ones (Magiran, SID, IranMedex, Irandoc). Following removal of duplicate citations and irrelevant studies, the full texts of the remaining publications were prepared and assessed for more detail.
Results: Perceived discomfort in low back region obtained the highest score in workers of industrial, administrative, service, and agricultural settings. However, in the handicraft and educational groups, the highest percentage of discomfort was belonged to neck (66.7%). Findings showed that the most commonly used techniques for evaluation of musculoskeletal disorders and risk factors were, respectively, Nordic questionnaire (NMQ) (76%) and REBA (13.9%). Moreover, all identified risk factors were classified into eleven groups including: biomechanical, work environment design, tools, equipment, temporal aspects of job design, job content, organizational aspects, economic and financial issues, social aspects, individual characteristics, and training.
Conclusion: Overall, a wide range of risk factors reported in the previous studies were categorized in the present review. The results are suggested to be considered by managers and decision makers as a framework to take measures for controlling musculoskeletal disorders to accomplish the goal of ergonomics, which is productivity and well-being.

---

Introduction: Work-related musculoskeletal disorders (WMSDs) are a prevalent occupational health concern, influenced by both physical and psychosocial factors. Valid questionnaires offer a cost-effective and efficient means of evaluating WMSDs. This study aimed to validate the Persian version of the MDRF questionnaire, assess its applicability in Iran, and investigate the prevalence of WMSDs among employees in an automotive industry.
Material and Methods: This descriptive cross-sectional study was conducted among 100 employees (50 production line workers and 50 office workers) in Kerman province. The linguistic validity of the questionnaire and its translation were ensured using the Backward-Forward method. Content validity was assessed through CVI and CVR indexes. To evaluate the questionnaire’s reliability and agreement, Cronbach’s alpha and ICC were employed. User responses from the first and second series of the questionnaires were validated using Kappa and Spearman’s tests.
Results: Results indicated high reliability which was achieved by Cronbach’s alpha and ICC values of 0.960 and 0.925, respectively. The questionnaire’s validity was acceptable based on CVR and CVI tests. The prevalence of WMSDs was the highest in the lower back for both production line and office workers over the past year. The job satisfaction factor exhibited the highest risk level among the questionnaire’s four subgroups. Approximately 85% of participants were classified as having a high or very high-risk level, reflecting concerning conditions among the employees. The prevalence of WMSDs in different body parts significantly correlated with all physical and psychosocial stress factors.
Conclusion: This research highlights the influence of diverse physical and psychosocial risk factors on the occurrence of WMSDs among both occupational workers and office employees. Also, the MDRF questionnaire, whose high applicability in assessing the WMSDs risk factors was proven in this study, is an effective tool for prioritizing, planning, and executing educational and preventive measures within the workforce community to mitigate and prevent WMSDs. 

---

Introduction: Lifting loads in awkward postures is a main cause of low back musculoskeletal disorders. In this context, researchers have used various indicators to determine the relationship between biomechanical variables and the risk of these disorders. This study aimed to investigate the correlation between plantar pressure distribution and the values of UTAH back-compressive forces (BCF) and lifting index (LI) during symmetrical load-lifting tasks.
Material and Methods: Thirteen healthy men, aged 25 to 35, took part in this study. The participants were instructed to symmetrically lift loads weighing 7.5 kg and 15 kg in 15 different postures, considering three horizontal distances (A, B, C) and five different heights (1-5). Pressure on the foot soles was recorded using 16 force-sensitive resistors (FSR) corresponding to eight anatomical areas on each foot. The BCF and LI were also calculated using the UTAH method and the NIOSH equation, respectively. Statistical analysis was performed using SPSS (version 21) software.
Results: Based on the results, when the load was closest to the body (A1-A5), the highest pressure was recorded in the heel and the 4th and 5th metatarsal of both feet. In lifting a load of 15 kg in the A2, B1, B2, C1, C2 postures and lifting a load of 7.5 kg in the C2 posture, the average BCF exceeded 700 pounds. The LI was greater than 1 for specific postures (B1, B2, B4, B5, C1-C5) at 15 kg and (C1, C2, C4, C5) at 7.5 kg load-lifting. During the 7.5 kg and 15 kg load-lifting, there was a significant correlation between the plantar pressure and the values of LI and UTAH (p-values < 0.05) in most postures.
Conclusion: The results showed a significant correlation between plantar pressure distribution and load-lifting postures. The study findings, which identify risk levels associated with lifting postures, lay the groundwork for future research aimed at categorizing safe and unsafe plantar pressure patterns.