IISE transactions on occupational ergonomics and human factors最新文献

OCCUPATIONAL APPLICATIONSFalls from ladders remain a significant cause of injuries in workplaces as well as residential settings. While recent research reveals factors related to fall severity from a ladder, strategies that workers can adopt to minimize fall severity are not well understood. Results from our current study indicated that increased upper limb strength, achieving a higher hand hold, and controlled reestablishment of the foot on the rung have summative benefits to reduce fall severity and increase recovery from a misstep perturbation. Ensuring adequate upper limb strength among workers, and training workers to climb ladders leading with hand placement during ascent and foot placement during descent, can facilitate these beneficial strategies to arrest a ladder fall.

Occupational ApplicationsWe investigated the association between postural variability during a surgical procedure and both perceived back load and self-reported low-back pain history among surgical assistants. Postural variability was assessed using the standard deviations of lumbar flexion (directly related to trunk extensor muscle length) and trunk inclination (a predictor for back loading). Lumbar flexion variability showed a significantly negative correlation with both perceived back load during the measured procedure and perceived back load during the measured procedure relative to a typical procedure. However, neither of the variability measures yielded an association with low-back pain history. Although our study does not show an association between postural variability and low-back pain, it does suggest that variation in trunk extensor muscle length may reduce short-term perceived back load. Variation in lumbar flexion could be evoked on the work-floor by various types of interventions aimed at increasing postural variability.

OCCUPATIONAL APPLICATIONSSmall deviations in individual joint angles (<5°) simulated using a simple probabilistic computational model resulted in significant and meaningful changes in upper limb and trunk joint moments, by up to 20% of mean population joint strength. Moment tradeoffs between the upper extremity and trunk were also observed and depended upon work height and individual anthropometrics. Our work challenges the common practice of ergonomists and human factors practitioners to analyze task demands based on one representative posture. We recommend practitioners instead consider variability in adopted postures, as captured by monitoring worker kinematics over the course of a day. The sensitivity of joint demands to small postural changes also underscores the need for using reliable kinematic measurement tools in the field, since results from ergonomic analyses and consequently decision-making can be susceptible to large discrepancies despite small differences in postural inputs.

OCCUPATIONAL APPLICATIONSAs extended reality (XR) technologies continue to evolve, their use in remote collaboration and workplaces with physical limitations offers opportunities to improve ergonomics and efficiency. In this study, we explored how virtual reality (VR) and mixed reality (MR) systems impact users' sense of presence, perceived workload, object manipulation, and physiological responses in remote collaboration settings with movement constraints. We found that VR-based collaboration enhanced the sense of presence and reduced the need for physical movement compared to MR. Specifically, features such as a thumbstick button enabled teleportation in VR to help minimize physical strain. In contrast, MR systems led to higher objective and subjective measures of physical demands, suggesting greater strain and potential fatigue from ongoing physical interactions. Our findings highlight the importance of designing XR systems that balance productivity with worker well-being, particularly in environments that require physical adaptability.

Occupational ApplicationsWe interviewed 24 automotive logistic workers who had used (or stopped using) a soft back-support exoskeleton (exosuit). These workers generally recognized potentially benefits of back-support exosuits, with 11 continuing use. Their use was primarily influenced by usability, compatibility, and comfort factors. We found wide variability in use patterns and adaptation periods, and that there were specific design concerns and concerns regarding thermal discomfort. To enhance long-term adoption of exosuits in industrial settings, organizations should consider: 1) implementing flexible, individualized training programs addressing specific usability challenges; 2) adopting a voluntary approach accommodating varied adaptation needs; 3) providing comprehensive education on potential health benefits; 4) using peer demonstrations to promote acceptance; and 5) collaborating with manufacturers to improve designs based on user feedback. These strategies may help enhance acceptance and sustained use of exosuits, potentially contributing to more effective support for occupational health during manual material handling tasks.

OCCUPATIONAL APPLICATIONSHands are frequently exposed to the risks of musculoskeletal disorders (MSDs) due to their involvement in tool handling. We propose a computer vision-based pipeline that can accurately recognize the types of hand grips during tool handling using monocular red, green, and blue (RGB) images. While the predominant methods for hand ergonomics assessments require considerable training for practitioners, the proposed pipeline can facilitate assessments by providing crucial information, such as grip types, duration, and repetition, in a continuous and noninvasive manner. The proposed pipeline could support preventative measures, early diagnosis, and effective treatments for hand-related MSDs in workspaces. Additionally, the simple setup of the proposed pipeline can be integrated with other ergonomics assessment tools that are not limited to the hands, contributing to a more comprehensive analysis of MSD risks across body parts.

OCCUPATIONAL APPLICATIONSWe conducted a study on offshore drillships in the Gulf of Mexico that captured daily compliance rates with various fatigue assessments over four weeks-a Psychomotor Vigilance Task (PVT), actigraphy, physiological monitoring, and surveys. We obtained worker perceptions of these assessments' utility, effectiveness, and feasibility. Each fatigue assessment had a good overall compliance rate (>80%) over the four weeks but declined when the assessment was self-administered. Our interview findings revealed that actigraphy was the preferred means of monitoring their sleep to manage fatigue compared to physiological sensors. Workers also perceived PVT outcomes to be useful, but the duration (∼10 min) was the biggest barrier to continued use. From these findings, we generated research-to-practice recommendations on effective and sustainable fatigue assessments in offshore shiftwork: (1) periodic use of actigraphy watches to monitor sleep time and efficiency and (2) implementation of a short 3- or 5-min PVT on an electronic device.

Occupational ApplicationsIn this study, healthy adults performed repetitive bilateral overhead shoulder flexion to fatigue-failure while we measured electromyography of shoulder muscles. We found that ambidextrous and right-handed individuals, especially females, exhibit asymmetrical muscle activation patterns during the task. To enhance worker health and safety, handedness and sex should be considered when implementing workplace changes. For instance, our results may imply that job rotation strategies that alternate use of hands would be easier to implement for males. Moreover, to minimize risk of injury, bilateral asymmetry in muscle activity could be monitored using wearable technology. In our experiment, the mean time to fatigue-failure was under 5 min, which was enough to elicit asymmetry of muscle activation. Therefore, we recommend frequent breaks after a few minutes of work when feasible, in order to avoid asymmetrical loadings during bilateral manual work, especially among females, who both have higher injury risk and more bilateral asymmetry.

OCCUPATIONAL APPLICATIONSWe present methods to characterize individual day-to-day variation in physical behaviors, either by assessing variation in one behavior in isolation or multiple behaviors simultaneously. These methods could be used in future studies to evaluate the health implications of variation in occupational exposures. For example, the method presented for characterizing variation in a single behavior can be used to investigate how day-to-day variation in time spent standing relates to risks of developing musculoskeletal pain. However, it may be that the health risks associated with variation in one occupational exposure (e.g., standing) depend on the variation in other occupational exposures (e.g., sitting). The method presented for assessing variation in multiple behaviors could facilitate the exploration of such research questions. This method could also be used by practitioners to evaluate the effectiveness of interventions aimed to enhance variation in workplaces.