A time study was conducted to evaluate the operation efficiency and the risk of musculoskeletal disorders (MSDs) for using the Power Stow Rollertrack Conveyor (PSRC) for baggage handling in the cargo holds of narrow-bodied aircrafts. The PSRC employs a retractable roller conveyor from a belt loader to provide powered transportation for loading and unloading baggage in the cargo holds. Thirteen baggage handlers at the Boston Logan International Airport participated in the data collection, which involved videotaping their work postures and methods during baggage handling operations in the cargo holds of the Boeing 737 and 757 aircrafts. Results showed that the PSRC provided improved efficiency in handling baggage, especially for unloading baggage by about 2 bags per minute. There was no significant difference in the total time spent on the risk factors for MSDs, such as lifting, pushing and pulling tasks per person for each bag between PSRC users and non-users. © 2023 Human Factors and Ergonomics Society.

OBJECTIVE: The objective was to evaluate the efficacy of the Revised National Institute for Occupational Safety and Health (NIOSH) lifting equation (RNLE) to predict risk of low back pain (LBP). BACKGROUND: In 1993, NIOSH published the RNLE as a risk assessment method for LBP associated with manual lifting. To date, there has been little research evaluating the RNLE as a predictor of the risk of LBP using a prospective design. METHODS: A total of 78 healthy industrial workers' baseline LBP risk exposures and self-reported LBP at one-year follow-up were investigated. The composite lifting index (CLI), the outcome measure of the RNLE for analyzing multiple lifting tasks, was used as the main risk predictor. The risk was estimated using the mean and maximum CLI variables at baseline and self-reported LBP during the follow-up. Odds ratios (ORs) were calculated using a logistic regression analysis adjusted for covariates that included personal factors, physical activities outside of work, job factors, and work-related psychosocial characteristics. RESULTS: The one-year self-reported LBP incidence was 32.1%. After controlling for history of prior LBP, supervisory support, and job strain, the categorical mean and maximum CLI above 2 had a significant relationship (OR = 5.1-6.5) with self-reported LBP, as compared with the CLI below or equal to 1. The correlation between the continuous CLI variables and LBP was unclear. CONCLUSIONS: The CLI > 2 threshold may be useful for predicting self-reported LBP. Research with a larger sample size is needed to clarify the exposure-response relationship between the CLI and LBP.

Occupationally-induced back pain is a leading cause of reduced productivity in industry. Detecting when a worker is lifting incorrectly and at increased risk of back injury presents significant possible benefits. These include increased quality of life for the worker due to lower rates of back injury and fewer workers' compensation claims and missed time for the employer. However, recognizing lifting risk provides a challenge due to typically small datasets and subtle underlying features in accelerometer and gyroscope data. A novel method to classify a lifting dataset using a 2D convolutional neural network (CNN) and no manual feature extraction is proposed in this paper; the dataset consisted of 10 subjects lifting at various relative distances from the body with 720 total trials. The proposed deep CNN displayed greater accuracy (90.6%) compared to an alternative CNN and multilayer perceptron (MLP). A deep CNN could be adapted to classify many other activities that traditionally pose greater challenges in industrial environments due to their size and complexity.

In 2017, the order Mononegavirales was expanded by the inclusion of a total of 69 novel species. Five new rhabdovirus genera and one new nyamivirus genus were established to harbor 41 of these species, whereas the remaining new species were assigned to already established genera. Furthermore, non-Latinized binomial species names replaced all paramyxovirus and pneumovirus species names, thereby accomplishing application of binomial species names throughout the entire order. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).

Video-based posture analysis employing a biomechanical model is gaining a growing popularity for ergonomic assessments. A human posture simulation method of estimating multiple body postural angles and spinal loads from a video record was developed to expedite ergonomic assessments. The method was evaluated by a repeated measures study design with three trunk flexion levels, two lift asymmetry levels, three viewing angles, and three trial repetitions as experimental factors. The study comprised two phases evaluating the accuracy of simulating self- and other people's lifting posture via a proxy of a computer-generated humanoid. The mean values of the accuracy of simulating self- and humanoid postures were 12° and 15°, respectively. The repeatability of the method for the same lifting condition was excellent (~2°). The least simulation error was associated with side viewing angle. The estimated back compressive force and moment, calculated by a three-dimensional biomechanical model, exhibited a range of 5% underestimation. The posture simulation method enables researchers to quantify simultaneously body posture angles and spinal loading variables with accuracy and precision comparable to on-screen posture-matching methods.

OBJECTIVE: To evaluate whether the Revised NIOSH Lifting Equation (RNLE) is a valid tool for assessing risk of low back pain (LBP) due to manual lifting by using combined data from two cross-sectional studies of 1-year prevalence. METHODS: Results from a symptom and occupational history questionnaire and RNLE analysis for 677 subjects employed in 125 manual lifting jobs at nine industrial sites were combined from two studies. RESULTS: The odds of LBP increased as the lifting index (LI) increased from 1.0 to 3.0. A statistically significant odds ratio (OR) was found for both the 1 < LI ≤ 2 (OR = 1.81) and the 2 < LI ≤ 3 categories (OR = 2.26). For jobs with an LI value greater than 3.0, however, the OR remained nonsignificant. The 2 < LI ≤ 3 group remained statistically significant after adjusting for age, gender, body mass index, and psychosocial factors. CONCLUSIONS: It is clear that as the LI increases, the risk of LBP increases. Longitudinal studies are needed.

The estimation of cumulative spinal load (CSL) resulting from exposure to manual materials handling (MMH) may provide a sensitive method for assessing the risk of highly varying exposures. This article reports on a CSL method that involves human posture simulation of workers from videotape in order to assess spinal load exposures due to MMH. The proposed method appears to be sensitive to different durations of exposure, easy to use and useful for assessing jobs with a high degree of variability in task characteristics between lifts. Although the method remains to be validated, it appears to be a useful addition to the range of tools available for assessing manual lifting exposures in worksite-based epidemiologic studies. Ergonomic methods are lacking for assessing highly variable MMH tasks, such as tasks found in warehousing. The existing methods do not include sufficient factors to account for variable exposure patterns or tasks with highly variable task characteristics, such as varying load weights and lift geometries. The CSL assessment method described in this article may provide a way to evaluate these types of tasks in order to assess the overall risk of workers developing work-related musculoskeletal disorders.

For assessing a large number of variable manual lifting jobs, posture specification for using the University of Michigan Three Dimensional Static Strength Prediction Program and the revised National Institute for Occupational Safety and Health Lifting Equation may be time-consuming, tedious and subject to human errors. To expedite data analysis with desirable accuracy and precision for the two risk assessment tools, a new data analysis method based on human posture simulation was developed and evaluated. The accuracy and precision of the posture simulation method were evaluated by a repeated measures study design with six postures, three viewing angles and three trial repetitions as experimental factors. The effects of the experimental factors on the average accuracy and precision of the simulation method are reported and discussed. The study results also demonstrated pros and cons of human posture simulation as a means of posture specification for ergonomic risk assessments. The findings about the accuracy and precision of the human posture simulation method for quantifying the risk of musculoskeletal disorders due to manual materials handling may provide researchers with a new way of ergonomic assessments.