International Journal of Industrial Ergonomics最新文献

Touchscreen in-vehicle central control interfaces are rapidly replacing traditional physical buttons. However, the differences in the effects of tactile feedback between touchscreens and physical buttons on driver emotions are unclear. This study used a simulated driving experiment to investigate the effects of tactile feedback mode and intensity on driver emotion using the Self-Assessment Manikin (SAM). The results showed that tactile feedback mode, intensity, and difficulty of non-driving-related tasks (NDRTs) significantly affected drivers' emotional states. Touchscreen tactile feedback elicited a more positive emotional state than physical button tactile feedback. The intensity of touchscreen tactile feedback is positively correlated with driver emotional valence. However, higher-intensity physical button feedback decreases driver emotional valence, particularly when drivers are engaged in complex NDRTs, and the difference due to feedback intensity is insignificant. The study's results could help automakers intervene by designing tactile feedback to enhance the emotional experience of the driver's in-vehicle interaction interface.

The purpose of this study was to determine the maximal biomechanical and physiological effects of implementing an active sitting protocol while using an active chair, compared to the use of a traditional office chair, and standing workstation. The active chair had a seat pan split longitudinally, enabling the participant to pedal their feet while seated. The active sitting protocol consisted of participants actively plantarflexing and dorsiflexing their ankles in a “stepping” motion to the sound of a metronome, operating at 40 beats per minute. Twenty-four healthy participants performed computer tasks at each of the workstations for 30-min. For each collection period, participants’ biomechanical and physiological responses were recorded using electromyography (EMG); near-infrared spectroscopy (NIRS); pressure distribution mats; electrodermal activity (EDA); heart rate (HR) monitor; and subjective discomfort survey. Statistical analysis was conducted using a repeated measures analysis of variance, with a Tukey correction post-hoc analysis for significant findings. There were few significant findings in our biomechanical measures that separated the active chair from the traditional office chair and the standing workstation. However, this study demonstrated that the active sitting protocol had positive physiological effects for the user, with the greatest benefit being the significant increase in blood oxygenation levels to the gastrocnemius.

Cognitive health screening for aviators would assist in managing a shortage of experienced pilots. Extending pilot careers by optimizing their cognitive health would address both the number and quality of pilots available for airline and general aviation operations. The present work tested the validity of an online screening tool for pilots that measures aviation domain-relevant cognition. Sixty-five licensed pilots (18–80 years, M = 48.8, SD = 16.3) with varying levels of experience completed a 30-min online cognitive health screening tool for pilots. Risk status was determined via a novel metric using self-reported incidents. Machine learning algorithms identified the cognitive factors most useful in identifying pilots with increased risk for accidents and serious incidents. Support vector machines and boosted decision tree algorithms provided the most reliable and strongest classifications models of pilot risk. Findings support the use of this short online screening tool for highlighting performance issues with domain-relevant cognitive abilities based on the Dynamic Mental Model for pilots, such as situation awareness and prospective memory. Understanding personal cognitive challenges is the basis for customized skill maintenance designed to augment cognition for those interested in safely extending their piloting careers.

A variety of interaction devices are increasingly used for human-computer interaction (HCI) tasks in ship vibration conditions, but have seldom been well assessed. This study aimed to examine task performance, upper limb muscle activity, and perceived fatigue and device usability for four typical interaction devices (i.e., mouse, trackball, touchscreen, and Leap Motion) under simulated ship vibration conditions. A two-factor within-subjects design was employed in this study, where participants performed basic HCI tasks with the four interaction devices under three conditions (i.e., static condition, and low and high vibration conditions). The results showed that vibration condition significantly reduced task performance, especially for Leap Motion. Differences in task performance, upper arm and shoulder muscle activities, perceived fatigue and device usability were found among interaction devices. Mouse and touchscreen achieved the best task performance, compared with trackball and Leap Motion, while both touchscreen and Leap Motion achieved larger upper limb muscle activities, compared with trackball and mouse.

Relevance to industry

The findings provide important implications for the use and configuration of interaction devices, and for the development of prevention interventions for risks of musculoskeletal disorders in using interaction devices under ship vibration conditions.

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.