Trunk Flexion Monitoring among Warehouse Workers Using a Single Inertial Sensor and the Influence of Different Sampling Durations

Trunk flexion represents a risk factor for the onset of low-back disorders, yet limited quantitative data exist regarding flexion exposures in actual working conditions. In this study, we evaluated the potential of using a single inertial measurement unit (IMU) to classify trunk flexion, in terms of amplitude, frequency, and duration, and assessed the influence of alternative time durations on exposure results. Twelve warehouse workers were monitored during two hours of an actual shift while wearing a single IMU on their low back. Trunk flexion data were reduced using exposure variation analysis integrated with recommended exposure thresholds. Workers spent 5.1% of their working time with trunk flexion of 30-60° and 2.3% with flexion of 60-90°. Depending on the level of acceptable error, relatively shorter monitoring periods (up to 50 min) might be sufficient to characterize trunk flexion exposures. Future work is needed, however, to determine if these results generalize to other postural exposures and tasks

Load-relaxation properties of the human trunk in response to prolonged flexion: measuring and modeling the effect of flexion angle

Experimental studies suggest that prolonged trunk flexion reduces passive support of the spine. To understand alterations of the synergy between active and passive tissues following such loadings, several studies have assessed the time-dependent behavior of passive tissues including those within spinal motion segments and muscles. Yet, there remain limitations regarding load-relaxation of the lumbar spine in response to flexion exposures and the influence of different flexion angles. Ten healthy participants were exposed for 16 min to each of five magnitudes of lumbar flexion specified relative to individual flexion-relaxation angles (i.e., 30, 40, 60, 80, and 100%), during which lumbar flexion angle and trunk moment were recorded. Outcome measures were initial trunk moment, moment drop, parameters of four viscoelastic models (i.e., Standard Linear Solid model, the Prony Series, Schapery\u27s Theory, and the Modified Superposition Method), and changes in neutral zone and viscoelastic state following exposure. There were significant effects of flexion angle on initial moment, moment drop, changes in normalized neutral zone, and some parameters of the Standard Linear Solid model. Initial moment, moment drop, and changes in normalized neutral zone increased exponentially with flexion angle. Kelvin-solid models produced better predictions of temporal behaviors. Observed responses to trunk flexion suggest nonlinearity in viscoelastic properties, and which likely reflected viscoelastic behaviors of spinal (lumbar) motion segments. Flexion-induced changes in viscous properties and neutral zone imply an increase in internal loads and perhaps increased risk of low back disorders. Kelvin-solid models, especially the Prony Series model appeared to be more effective at modeling load-relaxation of the trunk

Effects of Pacing When Using Material Handling Manipulators

Common manipulator-assisted materials handling tasks were performed in a laboratory simulation at self-selected and faster (paced) speeds. The effects of pacing on peak hand forces, torso kinematics, spine moments and forces, and muscle antagonism were determined, along with any influences of several task variables on these effects. The faster trials were performed 20% more rapidly than the self-paced trials. It was found that (a) achieving this level of performance required 10% higher hand forces and 5%-10% higher torso moments, (b) consistent torso postures and motions were used for both speed conditions, and (c) the faster trials resulted in 10% higher spine forces and 15% higher levels of lumbar muscle antagonism. On whole, these results suggest a higher risk of musculoskeletal injury associated with performance of object transfers at faster than self-selected speeds with and without a manipulator. Further analysis provided evidence that the use of manipulators involves higher levels of motor coordination than do manual tasks. Several implications regarding the use of material handling manipulators in paced operations are discussed. Results from this investigation can be used in the design, evaluation, and selection of material handling manipulators.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67067/2/10.1518_001872099779591240.pd

Ambulatory Clinic Exam Room Design with respect to Computing Devices: A Laboratory Simulation Study

Background—Challenges persist regarding how to integrate computing effectively into the exam room, while maintaining patient-centered care. Purpose—Our objective was to evaluate a new exam room design with respect to the computing layout, which included a wall-mounted monitor for ease of (re)-positioning. Methods—In a lab-based experiment, 28 providers used prototypes of the new and older “legacy” outpatient exam room layouts in a within-subject comparison using simulated patient encounters. We measured efficiency, errors, workload, patient-centeredness (proportion of time the provider was focused on the patient), amount of screen sharing with the patient, workflow integration, and provider situation awareness. Results—There were no statistically significant differences between the exam room layouts for efficiency, errors, or time spent focused on the patient. However, when using the new layout providers spent 75% more time in screen sharing activities with the patient, had 31% lower workload, and gave higher ratings for situation awareness (14%) and workflow integration (17%). Conclusions—Providers seemed to be unwilling to compromise their focus on the patient when the computer was in a fixed position in the corner of the room and, as a result, experienced greater workload, lower situation awareness, and poorer workflow integration when using the old “legacy” layout. A thoughtful design of the exam room with respect to the computing may positively impact providers’ workload, situation awareness, time spent in screen sharing activities, and workflow integration

Ambulatory Clinic Exam Room Design with respect to Computing Devices: A Laboratory Simulation Study

OCCUPATIONAL APPLICATIONS When comparing a typical exam room layout to the Department of Veterans Affairs (VA's) new exam room design, with respect to the exam room computing, primary care providers experienced significantly less mental workload and greater situation awareness when using the new exam room design. Further, providers rated the new exam room layout significantly higher in terms of being integrated with their clinical workflow and spent significantly more time in screen sharing activities with the patient. A more thoughtful design of the exam room layout with respect to the placement and physical design of the computing set-up may reduce provider cognitive effort and enhance aspects of patient centeredness by viewing the computer and electronic health record (EHR) it displays as an important mediator between provider and patient. This was achieved by using an all-in-one computer attached to a wall mount that moves the monitor along three axes, allowing for optimal screen positioning and adjustable depending upon the scenario. TECHNICAL ABSTRACT Background: Challenges persist regarding how to integrate computing effectively into the exam room, while maintaining patient-centered care. Purpose: Our objective was to evaluate a new exam room design with respect to the computing layout, which included a wall-mounted monitor for ease of (re)-positioning. Methods: In a lab-based experiment, 28 providers used prototypes of the new and older "legacy" outpatient exam room layouts in a within-subject comparison using simulated patient encounters. We measured efficiency, errors, workload, patient-centeredness (proportion of time the provider was focused on the patient), amount of screen sharing with the patient, workflow integration, and provider situation awareness. Results: There were no statistically significant differences between the exam room layouts for efficiency, errors, or time spent focused on the patient. However, when using the new layout providers spent 75% more time in screen sharing activities with the patient, had 31% lower workload, and gave higher ratings for situation awareness (14%) and workflow integration (17%). Conclusions: Providers seemed to be unwilling to compromise their focus on the patient when the computer was in a fixed position in the corner of the room and, as a result, experienced greater workload, lower situation awareness, and poorer workflow integration when using the old "legacy" layout. A thoughtful design of the exam room with respect to the computing may positively impact providers' workload, situation awareness, time spent in screen sharing activities, and workflow integration.Agency for Health care Research and Quality (AHRQ), U.S. Department of Health and Human Services [1R03HS024488-01A1]12 month embargo; published online: 8 June 2018This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Transcultural Brokerage: The Role of Cosmopolitans in Bridging Structural and Cultural Holes

The growth and proliferation of global systems and transnational cultures have generated larger and more diverse types of cosmopolitans, all of whom span conventional social boundaries. Understanding this diversity is increasingly important because cosmopolitans often bridge across a wide range of transnational and global networks within and across global organizations. Drawing on multiple disciplines, we conceptualize cosmopolitanism as an embodied disposition characterized by high levels of cultural transcendence and openness that are manifested in and enacted along varied trajectories of cultural embeddedness in one’s own culture and cultural engagement with the cultural Other. We then propose an analytical framework for the influence of cosmopolitan disposition on transcultural brokerage processes, specifically on bridging structural and cultural holes. Finally, we present a typology of cosmopolitan brokers and their corresponding practices and activities as they engage in transcultural brokerage. By recognizing the diversity of cosmopolitans and their respective dispositions, we significantly expand the pool of “global talent” beyond the traditional focus on expatriates, and we challenge the conventional wisdom on who counts as talent in an interconnected world

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Perception-Behavior Engineering, an integrated human factors methodology, is proposed to integrate more systematically user perceptions and behavior-related information into design. The major merits of this approach are: 1) elicitation of perceptions and behaviors that are strongly related to design improvement; 2) establishment of the interrelationships between perceptions, behaviors, and design attributes; and 3) explicit application of these relationships while designing a product. First, the 4-phase process (i.e., perception spanning, behavior spanning, matching, and design/evaluation) that constitutes Perception-Behavior Engineering will be presented, and then comparisons will be made with existing methods such as Sensibility (Kansei) Engineering and Human Factors Engineering. In order to verify its practicality, the proposed process was applied to the driver workspace and interface design

Exploration of Different Classes of Metrics to Characterize Motor Variability During Repetitive Symmetric and Asymmetric Lifting Tasks

The substantial kinematic degrees-of-freedom available in human movement lead to inherent variations in a repetitive movement, or motor variability (MV). Growing evidence suggests that characterizing MV permits a better understanding of potential injury mechanisms. Several diverse methods, though, have been used to quantify MV, but limited evidence exists regarding the merits of these methods in the occupational context. In this work, we explored different classes of methods for characterizing MV during symmetric and asymmetric box lifting tasks. Kinematic MV of both the whole-body center-of-mass (COM) and the box were quantified, using metrics derived from a linear method (Standard Deviation), a non-linear method (Sample Entropy; an index of movement regularity), and a novel application of an equifinality method (Goal Equivalent Manifold; an index related to the set of effective motor solutions). Our results suggest that individuals manipulate regularity and the set of effective motor solutions to overcome unwanted motor noises related to the COM. These results, together with earlier evidence, imply that individuals may prioritize stability over variability with increasing task difficulty. Task performance also appeared to deteriorate with decreasing variability and regularity of the COM. We conclude that diverse metrics of MV may be complimentary to reveal differences in MV