International Journal of Industrial Ergonomics最新文献

Repeated high-g shocks and whole-body vibration (WBV) as experienced by operators of High-Speed Craft (HSC) increase the risk of fatigue, back pain, and acute and chronic injuries, especially in the lumbar region of the spine. Studies on abdominal belts have suggested their beneficial effects on lumbar torso stabilisation and back pain mitigation in both weight lifting and HSC scenarios. This paper presents a human musculoskeletal model to simulate belt effects for occupants on HSC under high-g shocks. Parameters included the shock severity with peak acceleration ranging from 3 g to 10 g, human dimensions and muscle strengths, the belt width and belt forces are investigated. The results show an average of 120% increase in the intra-abdominal pressure (IAP), a 9% reduction in the transverse abdominis activities, and a 12% reduction in the spinal compressive force at the L4/L5 joints when the abdominal belt is added to the human model. In conclusion, wearing an abdominal belt significantly assists abdominal muscles and maintains a solid core during intense WBV generated in different shock severity levels. It may cause a small negative influence on the neck region with a 2.4% increase in the shear force at the C4/C5 joints.

This study evaluates the effectiveness of four air insoles with varying thicknesses and one typical insole by measuring the total muscle activity, total muscle fatigue, left/right foot pressure symmetry ratio, and subjective fatigue among participants in three weight groups (<50, 50–70, and >70 kg). To minimize cumulative fatigue among participants, only one type of insole was tested per day. The 0.6- to 1.0-cm thick air insoles have a positive impact on muscle activity, muscle fatigue, and subjective fatigue compared to the typical 0.8-cm insoles. In terms of subjective fatigue, the 0.6-, 1.0-, and 1.2-cm air insoles yielded lower fatigue levels in the <50 kg group; however, the 50–70 kg group exhibited the lowest fatigue level when wearing the 0.8-cm air insoles. The proposed methodology may provide reference for optimal air insole thickness for users of varying weight ranges.

While cloud services make industrial data convenient, they also expose it to cloud incidents. Operators' error in cloud change activities is a leading factor for cloud incidents, which have received relatively less attention in cloud security research. This study conducted a two-stage research process using an integrated approach to explore the stable individual factors related to cloud change errors. First, in the qualitative research, content analysis based on interviews and historical documents was conducted to extract the operator's cognitive abilities and personality traits and develop hypotheses. Five cognitive abilities and six personality traits were extracted. Second, quantitative research based on an experiment was conducted to test relationships between operators' different types of cloud change errors and 1) cognitive ability and 2) personality traits, respectively. Results of error type comparisons suggested that operators generated more uncorrected errors than corrected errors and more operational errors than omission errors in cloud change activities. The multivariate Poisson regression analysis suggested that cognitive abilities of sustained attention, divided attention, and long-term memory negatively predicted the number of operators' total errors, uncorrected errors, and operational errors. Regarding personality traits, with the increase in resilience capacity and carefulness and the decrease in self-esteem, the number of different types of errors reduced, except for omission errors. Working memory and risk-taking propensity were also significant predictors of the number of uncorrected errors with negative and positive coefficients, respectively. Logical reasoning, emotional stability, and sense of responsibility were not observed as predictors of cloud change errors. The present findings have several implications for the industry and cloud providers to enhance industrial cloud data security regarding human cognitive abilities and personality traits.

Healthcare workers are highly susceptible to musculoskeletal injury, particularly in their lower back and shoulders. Manual patient transfers are common and can generate physical stresses that contribute to these injuries. Few studies have used in vivo musculoskeletal modeling to estimate the effect of slide boards and patient cooperation, and none have used measured hand forces as an input to the models. This laboratory study evaluated manual, one-person bed to wheelchair transfers of a 64 kg simulated patient using an instrumented gait belt that measured hand forces. Thirteen healthcare workers performed transfers with and without a slide board and with up to three levels of vertical assistance (0, 18, and 36% of patient body weight). In vivo lower back forces and resultant shoulder moments were estimated with a thoracolumbar musculoskeletal model using directly measured hand forces and full-body motion capture. Results indicated that slide boards and vertical assistance reduce physical stresses. However, all transfer conditions had trials that exceeded an ergonomic guideline. To provide some guidance on when a transfer can safely be performed manually, a post hoc analysis was performed to estimate the patient mass that can be safely transferred manually under ideal circumstances with only a gait belt. These findings have the potential to guide and credibly educate healthcare workers on when manual transfers are appropriate and when lifts are required. Regardless, mechanical lifts are still recommended in most circumstances to protect caregivers from injury and the patient from falling.

This laboratory-based study aimed to determine whether an arm-support exoskeleton (ASE) would be an effective intervention to reduce the physical strain associated with manual agricultural work. Twenty-four (gender-balanced) participants performed pruning and harvesting tasks (at four different heights: knee, elbow, shoulder, and overhead), lifting/lowering, and Timed Up & Go (TUG) tasks with and without an ASE. During these tasks, muscle activity (in the upper trapezius, anterior deltoid, biceps brachii, and erector spinae), task completion time, perceived exertion, and usability were assessed. The results indicated a significant reduction (31.7%–60.2%) in muscle activity, particularly in the upper trapezius and anterior deltoid, when using the ASE during tasks at shoulder work height or above. However, there was an observed increase in muscle strain in the erector spinae, suggesting potential risk to the lower back. Given these findings, a more rigorous evaluation of ASEs in agricultural tasks should be pursued before implementing exoskeletons in agricultural tasks to avoid unintended health hazards.

Relevance to industry

A relatively new application of exoskeleton technology, extensively studied in fields like rehabilitation, manufacturing, and the military, is its use in agriculture. This study details the physical requirements of specific tasks to offer insights into the challenges that exoskeleton technologies for agriculture may encounter.

The differences between ‘work as imagined’ (WAI) and ‘work as done’ (WAD) reflect theoretically pervasive and well-known barriers to the examination of human performance at work. Due to the dynamic and situational nature of the workplace, the idealized performance reflected in procedures is not always done as prescribed, and thus provides an excellent opportunity for examining divergence between WAI and WAD. The identification and examination of this gap and the nature of these deviations are imperative for high-risk industries to understand how workers' tools—in this case procedures—can be effectively designed and maintained. The present study used thematic analysis to compare procedure administrator and management performance expectations (representing WAI) to the realities of user performance (representing WAD) through interviews collected at several large, international chemical corporation sites. Direct comparisons of these perspectives revealed divergent expectations of how procedures are used and when they are most useful: Users reported deviating more often than administrators perceived the users deviate; users reported that tasks were the cause of the deviations more than administrators; and administrators thought that users may deviate from the procedures unintentionally while users did not report this. For a procedural system to perform optimally, these differences and the underlying processes that perpetuate them must be identified and further examined. To this end, relevant findings and theories from the human factors, ergonomics, and psychology literatures are identified and future directions are proposed.

This study investigated the effects of different driving durations on the distribution of seat interface pressure and the perceived comfort of vehicle occupants. The comfort of vehicle occupants was assessed using the Society of Automotive Engineers (SAE) scoring table, while pressure mats were employed to analyze pressure distribution during driving. The subjective and objective data underwent statistical analysis through repeated measures one-way ANOVA and Tukey's Honestly Significantly Different (HSD) test. Additionally, the mapping relationship between pressure variables and subjective comfort was investigated. The results indicated that the duration of driving had a significant impact on upper back contact pressure, left buttock contact force, lower back contact force, upper back contact area, and lower back contact area. The majority of pressure variables exhibited significant correlations with overall comfort, particularly in the area of lower back contact. Practical measures for enhancing long-term driving comfort were suggested based on the results of Principal Component Analysis (PCA) and the linear model. In addition, the developed nonlinear model successfully captures the driver's comprehensive comfort ratings, with an R2 value of 0.605. Our study revealed the patterns of subjective comfort and objective pressure distribution during the driving process, providing a reliable approach for evaluating seat comfort. Automotive seat development companies and designers can utilize these findings to enhance seat design and maintain comfort during prolonged periods of sitting. In summary, this study contributes to the development of the automotive seat comfort design industry.

Healthcare professionals are exposed to multiple physical risk factors related to the development of work-related musculoskeletal disorders (WRMSD), which significantly affect their quality of life. Several ergonomic methods have been developed for identifying risk factors in the workplace. Among these, wearable devices that perform direct measurements have demonstrated outstanding potential in recent years to provide reliable, non-invasive, and continuous exposure assessment. Therefore, this systematic review aims to describe the use of wearable technology for the ergonomic risk assessment of healthcare professionals. Twenty-nine publications were selected following PRISMA guidelines based on the inclusion and exclusion criteria set. Most of the articles were published in the last three years, confirming a growing trend in the research on this topic. Most wearable devices, which were used isolated or combined, consist of inertial sensors used to measure and assess the exposure to awkward postures and sEMG sensors, which provide the measurement of muscle activity parameters related to the force applied while performing work activities. The main results and respective analyses provided insights into the strengths and limitations of using wearable technology to acquire data on several work activities performed by healthcare professionals. Future research is needed to widen and validate the applicability of wearable technology in support of ergonomic interventions aimed at preventing the development of WRMSD among healthcare professionals.

Despite the advancements in autonomous vehicles (AVs) and their potential benefits, widespread acceptance of AVs remains low due to the significant barrier of trust. While prior research has explored various factors influencing trust towards AVs, the role of explainability—AVs’ ability to describe the rationale behind their outputs in human-understandable terms—has been largely overlooked. This study aimed to investigate how the perceived explainability of AVs impacts driver perception, trust, and the acceptance of AVs. For this end, an enhanced AV acceptance model that incorporates novel features such as perceived explainability and perceived intelligence was proposed. In order to validate the proposed model, a survey was conducted in which participants were exposed to different AV introductions (basic introduction, video introduction, or introduction with how + why explanations). The responses of 399 participants were analyzed using structural equation modeling. The results showed that perceived explainability had the most profound impact on trust, exerting both direct and indirect effects. AVs perceived as more explainable were also considered easier to use, more useful, safer, and more intelligent, which in turn fostered trust and acceptance. Additionally, the impact of perceived intelligence on trust was significant, indicating that drivers view AVs as intelligent agents rather than mere passive tools. While traditional factors such as perceived ease of use and perceived usefulness remained significant predictors of trust, their effects were smaller than perceived explainability and perceived intelligence. These findings underscore the importance of considering the role of explainability in AV design to address the trust-related challenges associated with AV adoption.

With the advancement of technology, color electronic paper displays have become the mainstream market in recent years. Thirty participants were recruited in this study to investigate the effect of color type (color, grayscale) and ambient illumination (200 lx, 750 lx, and 1500 lx) on legibility (search time, accuracy) and Positive and Negative Affect Schedule (PANAS) for different reading contents (charts, texts, and charts with texts [comics]). The results indicated that color type was significant on search time for charts and texts, significant on accuracy for texts and comics, and significant on PANAS for the three reading contents, while color displays performed better than grayscale displays. In addition, ambient illumination was significant on search time and PANAS for the three reading contents, and significant on accuracy for texts. The results showed that, at 200 lx, color charts and comics were recommended for reading. The results indicated that more than 750 lx was suitable for people to read charts. On the other hand, 1500 lx provided better legibility and a positive affect for people to read texts and comics. The results of this study could serve as a reference for the necessity of color electronic displays and the recommendation of suitable ambient illuminations with different reading contents.