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Objectives. This study examines which of the heart rate variability (HRV) and morphologic variability (MV) metrics may have the highest accuracy in different stress detection during real-world driving. Methods. The cross-sectional study was carried out among 93 intercity mini-bus male drivers aged 22–67 years. The Trillium 5000 Holter Recorder and GARMIN Virb Elite camera were used to determine heart rate and vehicle speed measurements along the path, respectively. We considered the HRV and MV metrics of electrocardiogram (ECG) signals including the mean RR interval (mRR), mean heart rate (mHR), normalized low-frequency spectrum (nLF), normalized high-frequency spectrum (nHF), normalized very low-frequency spectrum (nVLF), difference of normalized low-frequency spectrum and normalized high-frequency spectrum (dLFHF), and sympathovagal balance index (SVI). Results. The analysis showed that the HRV metrics mHR, mRR, nVLF, nLF, nHF, dLFHF and SVI are effective in mental stress detection while driving as compared to rest time. We obtained a high accuracy of stress detection for MV metrics as compared to the traditional HRV analysis, of approximately 92%. Conclusions. Our findings indicate that driver stress could be detected with an accuracy of 92% using MV metrics as an accurate physiological index of the driver's state. [ABSTRACT FROM AUTHOR]

Objectives. The decision-making trial and evaluation laboratory (DEMATEL) technique integrated with the analytic network process (ANP) is used for determination and prioritization of cause–effect relationships among factors affecting construction falls. Methods. Considering the 135 fall accidents collected between 2013 and 2018 from 15 residential construction projects, 70 factors and sub-factors affecting the occurrence of construction falls were determined based on safety experts' opinions. Questionnaires based on the former and the latter were then distributed among 10 occupational health and safety specialists to determine the effectiveness of the factors. The interactions and important degree of each factor are specified, using the DEMATEL–ANP approach. Results. Findings showed that organizational factors and their sub-factors have the greatest impact on construction falls and were considered as causal variables (D – R > 0), while individual and environmental factors were considered as the effect variables (D – R < 0). The results of prioritization using the ANP method showed that the work platform altitude, psychological/occupational stresses and interactions were ranked as the first through third priorities affecting the falls, respectively. Conclusions. It is necessary to implement a systematic strategy to reduce the unsafe conditions in construction projects and to pay more attention to organizational factors. [ABSTRACT FROM AUTHOR]

Background: Low back pain (LBP) is known as one of the most common workrelated musculoskeletal disorders. Spinal cumulative loads (CLs) during manual material handling (MMH) tasks are the main risk factors for LBP. However, there is no valid and reliable quantitative lifting analysis tool available for quantifying CLs among Iranian workers performing MMH tasks. Objective: This study aimed to investigate the validity and inter-rater reliability of a posture-matching load assessment tool (PLAT) for estimating the L5-S1 static cumulative compression (CC) and shear (CS) loads based on predictive regression equations. Material and Methods: This experimental study was conducted among six participants performing four lifting tasks, each comprised of five trials during which their posture was recorded via a motion capture (Vicon) and simultaneously a threecamera system located at three different angles (0°, 45°, and 90°) to the sagittal plane. Results: There were no significant differences between the two CLs estimated by PLAT from the three-camera system and the gold-standard Vicon. In addition, ten raters estimated CLs of the tasks using PLAT in three sessions. The calculated intra-class correlation coefficients for the estimated CLs within each task revealed excellent interrater reliability (> 0.75), except for CS in the first and third tasks, which were good (0.6 to 0.75). Conclusion: The proposed posture-matching approach provides a valid and reliable ergonomic assessment tool suitable for assessing spinal CLs during various lifting activities. [ABSTRACT FROM AUTHOR]