bluuebunny/crossref_metadata_2025 huggingface dataset:
Barriers to Effective Preoperative Handover Communication in the Neonatal Intensive Care Unit
Authors: Lorinc Amanda , Roberts David , Slagle Jason , Tice Jamie , France Daniel , Weinger Matthew B.
Published: October 2014

We sought to better understand the preoperative neonatal intensive care unit to operating room (NICU-to-OR) handover process and to elicit barriers to effective handovers. We first conducted observations of NICU-to-OR handovers to ascertain current handover practices, including the participants involved, handover content, as well as barriers and facilitators of effective handovers. We then developed a survey tool to assess the generalizability of our findings to other NICUs across the country. The resulting pilot data highlight key areas for future research and potential interventions to improve the quality of NICU-to-OR care transitions.
Eye Movement Behavior During Confusion
Authors: DeLucia Patricia R. , Preddy Doug , Derby Paul , Tharanathan Anand , Putrevu Sriharsha
Published: October 2014

The purpose of the present study was to develop a methodology to identify when a user is confused while using a product. Eye movements were measured to determine whether they reflect confusion while users completed tasks with two simulated devices. First, two devices that differed in subjective ratings of confusion were identified. Then eye movements and task performance were measured while experienced and inexperienced users conducted nine tasks with the devices. The relationship between eye movement and confusion measures depended on the task and the user group. Results provide a foundation for developing methods to identify and predict user confusion on the basis of eye movements, and ultimately to design products to avoid confusion.
Do People Understand their Home HIV Test Results? Risk Literacy and Information Search
Authors: Ellis Katrina M. , Cokely Edward T. , Ghazal Saima , Garcia-Retamero Rocio
Published: October 2014

HIV testing is recommended for most adults regardless of risk. Unfortunately, the high sensitivity and specificity of home HIV tests may often be misinterpreted. Here, we assessed risk comprehension in a sample of young adults who received the manufacture’s home HIV test brochure. Results indicated that most participants accurately answered some risk-relevant questions (e.g., what is the test sensitivity?). Individual differences in numeracy predicted more thorough review of relevant risk information and were associated with some superior inferences (i.e., estimating false negative rates). However, regardless of numeracy, participants tended to dramatically overestimate the probability that a positive test result was a true positive (i.e., the positive predictive value), showing marked overconfidence in their incorrect interpretations. Results highlight current strengths and limits of the standard informational brochure. Implications and opportunities for improving risk communication in Home HIV testing are briefly discussed.
Effects of Multimedia Interactivity on Spatial Task Learning Outcomes
Authors: Chen Dar-Wei , Catrambone Richard
Published: October 2014

Prior research has produced mixed results regarding the usefulness of interactivity in multimedia learning. In this study, participants learned to solve part of a Rubik’s Cube using either a tutorial with interactive features or a passive (video-based) tutorial. Participants with low spatial ability benefited more from interactivity than those with high ability, though no performance main effects were found between the tutorials. Targeted use of interactivity could be effective in engaging students and helping them learn.
Seeing is Believing
Authors: Quartuccio Jacob , Franz Simone , Gonzalez Christian , Kenner Naomi , Cades David M. , Sala Joseph B. , Arndt Steven R. , McKnight Patrick
Published: October 2014

Big data sets can be cumbersome and difficult to understand. User-centered and interactive graphical displays help communicate messages from large and complex data as well as provide a new method to identify data trends outside of tabular or statistical analysis. Human factors researchers can utilize data visuals to not only develop but also answer questions that previously proved difficult through visual exploration. This approach is especially relevant to the field of surface transportation research where complex plots can incorporate both temporal and geospatial data in an easy-to-digest format. As a proof of concept, this paper demonstrates how bike-sharing and historical bicycle collision incidents can meaningfully merge to produce graphical displays that readily identify and communicate potential infrastructure problems for safety. Through the use of Bayesian modeling and geospatial mapping, our analysis identifies two primary trends worth further consideration and research to consider for cyclist safety in Chicago.
Media Richness, Team Behaviors, and Task Complexity on Team Performance
Authors: Stone Nancy J.
Published: October 2014

Student groups worked a maze problem in a high or low media rich environment, with distributed or shared materials, with or without training on effective communication. Training did not affect performance, but groups with shared information had greater levels of performance. The media rich environment was debilitating, contrary to expectation. A training and materials interaction suggests that teamwork behaviors can decrease group performance when the task is easy, but increase performance on a more difficult task. Best predictors of performance suggest different types of behaviors have greater impact in different settings, and giving and seeking situation awareness might suggest a group is experiencing problems with the task.
Older Driver Detection of a Roadway Obstacle at Night
Authors: Curry David G. , Pergande Shaun
Published: October 2014

This paper represents an extension of a 2007 HFES Annual Meeting paper (Curry et al, 2007). The original paper focused on the nighttime detection of obstacles stopped along the sides of active road-ways by drivers between 20 and 60 years of age. The current paper focuses on a similar detection task, but utilizes a considerably older driver sample. It has been well-recognized for a number of years that driver visual capabilities begin to decline rapidly as the age of the motorist increases. This study was designed to quantify the relative detection distances of a variety of target vehicle characteristics by older, aware motorists on a darkened roadway.
Individual Differences in Human-Agent Teaming
Authors: Wright Julia L. , Quinn Stephanie A. , Chen Jessie Y.C. , Barnes Michael J.
Published: October 2014

Studies investigating the effects of level of autonomy (LOA) on workload and performance in human-agent teams typically utilize subjective measures, but do not often incorporate physiological measures. This paper examines how well eye movement data collected in a recent experiment converges with the findings suggested by the subjective measures. Several eye behavior measures (fixation count, average fixation duration, blink rate, saccade amplitude and pupil diameter) were evaluated, and findings based on these compared to findings of NASA-TLX and situation awareness questionnaires. In addition, individual differences due to perceived attentional control were evaluated. Findings indicate that the physiological measures account for variance in workload that typical subjective measures may not, as they are more sensitive to individual differences among participants.
Relationship between Variations in Single-nucleotide Polymorphisms and Warfighter Performance
Authors: Mead Patrick , Haro Elizabet , Mackie Ryan , De Los Santos Lorena , Lund Rachel
Published: October 2014

Previous research has demonstrated potential links between variations in single-nucleotide polymorphisms (SNPs) and performance on various cognitive tasks. This study replicated the methods previously used to investigate such relationships and attempted to extend the methods to comparing genetic variations and operational warfighter performance during naval training tasks. The goal was to determine if such methods could be applied to operational performance metrics and, if so, could the results of such investigations be utilized to enhance warfighter training programs and system designs. The study investigated the relationship between various SNPs in the brain-derived neurotrophic factor (BDNF) (rs6265) and catechol-O-methyltransferase (COMT) (rs4680) genes and performance on working memory, cued visual-spatial attention, and surface warfare combat tasks. Study results showed no significant effects with respect to cued visual-spatial attention but did indicate significant effects for BDNF allele “A” carriers regarding working memory accuracy. Finally, due to the limited types of training metrics that could be collected, statistical analysis of the link between genetic variation and warfighter performance could not be performed. However, the lessons learned from this study may provide guidance for future studies in such comparisons.
Measuring Sisu
Authors: Amato-Henderson Susan , Slade Darnishia , Kemppainen Amber
Published: October 2014

Sisu is a Finnish term loosely translated as endurance or resilience in the face of adversity. In the athletic arena, the construct of Mental Toughness (MT) similarly describes the ability of some top athletes to overcome challenge and persist. We sought to measure sisu, or mental toughness, within an academic context in an effort to understand if mental toughness may be one of the missing puzzle pieces in understanding individual differences in persistence in STEM majors and careers. Exploratory factor analysis yielded similar constructs underlying academic MT as compared to athletic MT. This preliminary research provides the first step in creating a reliable and valid tool to assess MT in academics. Further research establishing the reliability and validity of this construct is warranted given the finding that several MT factor correlations with academic self- efficacy existed. We believe the ability to identify and quantify one’s MT will serve as an important variable in understanding individual differences in challenging situations.
Differences in the three-dimensional typing forces between short and long travel keyboards
Authors: Hughes Margaret , Johnson Peter W.
Published: October 2014

Keyboards with shorter key travel are becoming widespread yet it is unknown whether there are any biomechanical differences in the typing forces when using these keyboards. If one keyboard promotes typing with more force, this may increase the risk for developing an upper extremity disorder. A total of 17 subjects typed on two short travel keyboards (<2.5 mm) and one long travel keyboard (4.0 mm). The magnitude and angle of the typing forces were measured in the x-, y- and z-axes using a thin, three-dimensional force platform. The aim of this study was to determine whether there were differences between the short and long travel keyboards in the magnitude and direction of the typing forces and the keystroke durations. In addition we wanted to determine whether there were typing force differences between key rows, hands, and fingers. Keyboards with shorter key travel resulted in less extreme angles and smaller magnitudes for forces applied in the x and y directions. Shorter travel distances were associated with smaller peak and mean vector sum forces and shorter keystroke durations. Although these results indicate keyboards with shorter key travel affect typing biomechanics, it is uncertain whether the small differences in keystroke durations and applied typing forces are physiologically meaningful and would reduce a computer user’s risk for developing an upper extremity musculoskeletal disorder.
Framing of Summary Risk/Safety Information and App Selection
Authors: Chen Jing , Gates Christopher S. , Proctor Robert W. , Li Ninghui
Published: October 2014

Participants recruited on Amazon’s Mechanical Turk performed a series of tasks in which they chose two Android apps from a list of six. Summary risk/safety information for each app was displayed in the form of one to five filled circles: The number of filled circles specified increasing risk for half of the participants and increasing safety for the other half. This summary information influenced the participants’ decisions, particularly when the app had high user ratings and when the decision was framed in terms of safety rather than risk. Participants indicated that they attended more to the risk/safety information when it was conveyed as amount of safety, and they showed better comprehension of what the index was conveying for safety as opposed to risk. The results imply that development of a valid risk/safety index for apps will improve users’ app-selection decisions, particularly if that information is displayed as amount of safety.
Biologically-Inspired Human-Swarm Interaction Metrics
Authors: Harriott Caroline E. , Seiffert Adriane E. , Hayes Sean T. , Adams Julie A.
Published: October 2014

Human-swarm interaction is an emerging field encompassing questions related to biology, robotics, computer science, human-computer interaction, and psychology. Swarms are large groups of individual entities that enact group behaviors; biological examples include fish, birds and insects. Swarms overwhelm humans’ abilities to monitor and interact with each entity. Human-robot and human-computer interaction metrics are inappropriate to describe human-swarm interactions alone due to the interaction challenges posed by swarms. It is unknown precisely how humans respond to interacting with swarms. The theory is that biological swarm metrics may be appropriate for analyzing human-swarm interaction. Nine human-swarm interaction metric categories derived from the biological and robotic swarm literature are presented, including example metrics from each category. This paper opens the discussion regarding what types of existing swarm metrics may be applicable and what categories of metrics will be important for human-swarm interaction assessment.
A Survey Applying the Concepts of Creation and Consumption to Common Tasks and Assessing Preferred Device Usage Between Desktops and Tablets
Authors: Guarrera-Schick Theresa K. , Lin Li , Fairbanks Rollin J. , Bisantz Ann M.
Published: October 2014

Tablets, although initially used as personal, entertainment devices, are more frequently appearing in the work environment. It has been suggested, but not empirically verified, that tablets are best suited for tasks where information is “consumed” whereas “creation” tasks are better suited to desktop or traditional computers. A survey was administered in order to better understand how tasks may be classified as consumption or creation tasks, and to determine if a relationship exists between this categorization and user preference to complete a task with a tablet or a traditional computer. Participants classified 57 tasks/applications according to consumption/creation dimensions, and according to their preference to complete the task on a tablet or desktop computer. Results indicate creation and consumption are not mutually exclusive categories and that device preference is not directly related to these categories. Results of this work may be used in the further design, development and evaluation of applications across devices.
Communication is More than Verbal
Authors: Zhang Wei , Pastel Robert
Published: October 2014

The software development process is a collaboration between developers, users experience experts, clients and other stakeholders. Several teams of Computer Science students developed citizen-science Android applications, working with scientists, the application clients and domain experts. We studied the applications’ development and determined the progress and performance of the teams by interviewing team members, studying their emails records, and documents shared by the scientists. The results from usability tests were used to measure the performance of the teams in terms of software correctness and usability. Our results showed that communication between clients and developers during the software development process is more complex than verbal. The quality of the documents shared by the clients is important.
High variability in Summative Usability Test methods & reporting among clinical informatics vendors complying with Federal certification requirements
Authors: Buchanan Christine , Threatt Anthony , Weinger Matthew B. , Miller Anne
Published: October 2014

The Office of the National Coordinator for Health Information Technology (ONC) has been tasked with managing the integration of usability best practices into electronic health record development but, has provided little guidance on how to conduct Summative Usability Testing (SUT). We reviewed three aspects of SUT in four publicly available SUT vendor reports. Significant deviations from human factors engineering (HFE) and user-centered design (UCD) best practices and clear methodological errors were found in all four reports. The main sources of variation involved non-representative participant selection, instructions that led participant performance, and varied interpretation of results reporting requirements. Although ONC has made significant gains in implementing best practice UCD approaches, more explicit guidance may be needed to enhance integrity and reduce variation.
Introducing an Automated System
Authors: Barg-Walkow Laura H. , Rogers Wendy A.
Published: October 2014

As automation becomes ubiquitous, it is important to know how differences in introducing automated systems will affect human-automation interactions. There are two main ways of introducing expected reliability of an automated system to users: explicitly telling operators what to expect or giving operators experience using the system. Additionally, the expected level of system reliability in an introduction can be higher-than, lower-than, or the same as the actual system reliability. This study systematically investigated the effect of introductions initially and over time on: 1) perceptions of reliability and system usage, and 2) human responses to automation (e.g., compliance, reliance, and overall dependence) for 60 undergraduates across two days. We found that explicit statements introductions had a greater effect on perceived system reliability than did initial exposure introductions, particularly initially. There were few initial differences between introduction formats on system usage. In general, system use stayed the same or increased as time using the system increased. These results can be used to inform how automated systems are introduced to users; depending on intended perceptions and uses of systems, different introductions should be considered.
Using Cursor Hints to Supplement a Less Interruptive Desktop Notification
Authors: Hung Ya-Hsin , Ostovari Mina
Published: October 2014

In this study we designed an assistive notification mechanism that did not interrupt users’ primary task so that they could focus on their main activity in a desktop environment. When a notification appeared in the peripheral area of the users’ field of view, we gave hints such as the color of cursor or a label to cursor to lead their attention to the notification that was originally outside of users’ field of view. To test our mechanism, we performed a multi-task experiment in a desktop environment with a word-finding game and the mouse cursor hints. The result revealed that the color hint as well as label hint coming from the cursor could increase the accuracy of participants’ ability to aware of the notification and decrease their subjective frustration while having little effect on their primary task. This implies that these approaches can be a potential assistive mechanism to current notification systems in a desktop environment.
Effects of Item Grouping on Selection Efficiency
Authors: Omanson Richard C. , Miller Craig S. , Joseph Sonetta V.
Published: October 2014

The effects of grouping items into categories were assessed for three methods of selection: 1) selecting a toolbar item with a mouse (Toolbar method); 2) selecting a menu item with a mouse (Menu method); and 3) selecting a menu item with a keyboard shortcut (Keyboard method). Users performed one of the three methods across 270 trials and had their speeds assessed in blocks of 30 trials. For each method, half the users selected items from a single menu or toolbar while the other half selected items from two menus or toolbars. Overall, the Keyboard method was the fastest, followed by the Toolbar method. When two menus or toolbars were used, users reported making category decisions regardless of the method used. With the Menu method, category decisions did not slow performance because they were offset by faster item selection due to fewer items in each menu when two menus were used. With the Toolbar method, the effect of fewer items in each toolbar when two toolbars were used was less pronounced. With the Keyboard method, there was no effect of fewer items in each menu because users recalled the keyboard shortcuts without looking at the menu items. These findings, coupled with past research that proficient use of the Keyboard method requires more trials than the other methods, confirm the use of toolbars for infrequently-used interfaces and keyboard shortcuts for frequently-used interfaces.
Macroergonomics in Healthcare
Authors: Carayon Pascale , Gurses Ayse P. , Holden Richard J. , King Barbara , Perry Shawna , Waterson Patrick , Wetterneck Tosha
Published: October 2014

In this panel, various researchers describe their macroergonomics research in healthcare with a particular focus on their use and adaptation of the SEIPS (Systems Engineering Initiative for Patient Safety) model of work system and patient safety (Carayon et al., 2006; Carayon et al., 2014). The panel discussion addresses questions on the past, present and future of macroergonomics research in healthcare, in particular regarding complex healthcare problems such as care transition and system redesign.
Ergonomic Risk and Homogeneous Exposure Groups
Authors: Miguez S.A. , Hallbeck M.S. , Vink P. , Rodrigues P.V.C.
Published: October 2014

This study shows what employees in the Environment, Health and Safety (EHS) area within private Brazilian companies think about the relationship between ergonomic risks and Homogeneous Exposure Groups (HEG). Thirty-seven professionals from different market segments answered a questionnaire via Google Docs. The results show that 75.6% of the companies sampled use HEG in order to map occupational risks. Within those companies, 54% include ergonomic risks in their HEG, which has negative consequences to both employees and employers in these companies.
A Proposed Relationship between Time and Load to Quantify Fatigue
Authors: Ahmed Shaheen , Babski-Reeves Kari , DuBien Janice , Webb Heather
Published: October 2014

Research has shown that both workload and time are associated with fatigue; however, a functional rela-tionship does not exist. This study observed sixteen participants in their workplace (computer programming and simulation) to quantify the workload-time-fatigue relationship for sedentary tasks. Equal numbers of participants were observed in the morning and afternoon sessions. Workload was measured both subjec-tively and objectively; while fatigue was measured using the Swedish Occupational Fatigue Inventory (SOFI) and a modified Borg scale. Forward selection stepwise regression analysis was performed to deter-mine the underlying mathematical relationship between workload, time, and fatigue. Results indicate that for sedentary tasks, fatigue is a hyperbolic function of workload and time; meaning an inherent interaction-only relationship between workload, time, and fatigue exists. Therefore, an individual can work for longer periods of time if the workload is minimal, and vice versa.
Screwdriver Bit Head Design – Effect of Phillips, Straight, and a Hybrid Design on Torque, Axial Force, and Effort Ratio
Authors: Hickok Mark D. , Marklin Richard W. , Nagurka Mark L. , Simoneau Guy
Published: October 2014

Advancements in fastener technology have been complemented by the development of new types of screwdriver bits. While designs may vary, so may the force application requirements placed on the tool user. The primary objective of this experiment was to analyze the relationship between user applied torque and screwdriver bit design. A further objective was to utilize the results to develop an effort metric by which bits of different designs can be compared. Three types of screwdriver bit designs (straight, Phillips, and combination of straight/Phillips (ECXTM)) were tested to determine how the design affects the amount and type of force applied by the user when performing a fastening task. The designs were tested to simulate fastener tightening and loosening operations. Sixteen participants were tested in this study. The data suggest there is no difference in user torque exertion between the ECXTM bit, Phillips, and the straight bit designs in either direction, 2.61-2.97 Nm for pronation and 2.63 -2.85 for supination. Mean axial force was significantly less for the Phillips (67 N) than the other 2 bits (72 and 80N). Although there was no significant effect of bit head design on maximal torque and axial force, the data suggest that the Phillips bit design may allow subjects to exert less axial force, which would result in a higher biomechanical effort ratio. A greater effort ratio would produce greater torque for the same axial force or the same torque for a lower axial force. Mean effort ratio for the Phillips bit was 3.6 N/N (Sup) and 4 N/N (Pro) and approximately 3.0 for the other two combinations of bits and directions. Subjective assessment indicated that users overwhelmingly preferred the Phillips bit design
Comparison of Exposure to Repetitive Upper Arm Motions and Non-neutral Upper Arm Postures between Apple Harvesting with Ladders and Mobile Platforms
Authors: Thamsuwan Ornwipa , Aulck Lovenoor , Galvin Kit , Johnson Peter W.
Published: October 2014

In attempts to improve productivity in agriculture, a harvest-assisting mobile platform has been developed and is being evaluated for use in Washington State apple orchards; however, its ergonomic effect on work postures and repetitive motions has not yet been characterized. The purposes of this study were: 1) to compare physical exposures between two methods of apple harvesting: a conventional ladder and a newly-developed mobile platform, and 2) to develop systematic methods for characterizing work repetitions, specifically in the upper arms. Using self-contained tri-axial inclinometers with built-in memory, upper arm inclinations were continuously monitored from twenty male workers over a full day of apple harvesting. At the beginning and the end of work shift, Borg CR10 scales were used as self-report measures of perceived fatigue in the shoulder. Postural exposures were characterized as the percent of time the upper arm postures exceeded specified angle ranges. Repetition was evaluated using changes in upper arm angles ranging from 5 to 30 degrees. In terms of prolonged postural exposures, repetitive work exposure and perceived fatigue in the shoulders, the workers using the mobile platform had less physical stress compared to the workers using the ladders. In addition, the upper arm repetition rates were high (over 15 repetitions per minute) for both harvesting methods. A more systematic study of the harvesting methods is needed to characterize differences in repetition rates and productivity between the mobile platforms and ladders. However, the results indicate that the mobile platform could improve workability and may enable more diverse workers to participate in harvesting activities.
An Ergonomic Evaluation of the Extravehicular Mobility Unit (EMU) Spacesuit Hard Upper Torso (HUT) Size Effect on Mobility, Strength, and Metabolic Performance
Authors: Reid Christopher R. , Harvill Lauren R. , Norcross Jason R. , Benson Elizabeth A. , England Scott A. , Young Karen , Rajulu Sudhakar L.
Published: October 2014

Introduction: The objective of this project was to develop a comprehensive methodology to assess the suit fit and performance differences between a nominally sized extravehicular mobility unit (EMU) spacesuit and a nominal +1 (plus) sized EMU. Method: This study considered a multitude of evaluation metrics including 3D clearances and pressure point mapping to quantify potential issues associated with using off-nominal suit sizes. Results: There were minimal differences with using a plus suit size. Discussion: Analysis of the results indicates that future suit size evaluations should consider this ergonomic approach to understand and mitigate potential suit fit and performance issues.
An Equation for Estimating Hand Activity Level Based on Measured Hand Speed and Duty Cycle
Authors: Akas Oguz , Azari David , Chen Chia-Hsiung (Eric) , Hu Yu Hen , Armstrong Thomas J. , Ulin Sheryl S. , Radwin Robert G.
Published: October 2014

We are developing video processing algorithms for automatically measuring the ACGIH TLV® hand activity level (HAL) using marker-less tracking of hand movements. An equation for computing HAL ratings directly from tracked kinematics, rather than using a frequency-duty cycle (DC) look-up table, more readily lends itself to automated processing. Videos from the 33 Latko et al. (1997) jobs were digitized and analyzed using marker-less tracking, and hand root mean square (RMS) speed (S) was measured. A linear regression model was developed for predicting the average observer rated HAL based on the measured hand RMS speed and DC. Since the videos did not contain distance calibration, speed was quantified in pixels/s and normalized by the distance of each worker’s hand breadth, measured in pixels. A Monte Carlo simulation was performed using the US Army (1991) hand anthropometry data to determine how variation is introduced in the equation as hand breadth varies. The resulting equation was HAL= −1.06 + 0.0047 S + 0.053 DC and it predicted HAL ratings within ±1. The development of an accurate equation for estimating HAL ratings should enable use of automated and objective measurement in practice. While expert observer HAL ratings offer speed and efficiency, use of objective measurements based on worker hand kinematics should provide greater reliability, as well as offering specific engineering aspects of the job that may be addressed for reducing exposures and the risk of musculoskeletal disorders. Furthermore, automated videos analysis may help improve the speed and efficiency of making objective measurements in practice.
Efficiencies in Imaging Diagnostics of the Lumbar Spine
Authors: Wade Chip , Cheng Boyle
Published: October 2014

While low back pain is one of the most prevalent, if not the most prevalent reasons for visits to physicians, a majority of patients with low back pain cannot be given a definitive diagnosis. The current standard of care for function assessment of the lumbar spine focuses on uncontrolled patient directed motion which results in increased inter-patient variability and diagnostic misclassifications. The purpose of the current paper is to compare the measurement variability of lumbar spine motion when diagnosed using measurements of intervertebral motion taken from standard flexion extension bending radiographs (FE) between uncontrolled and controlled motion and to assess the rate of diagnostic misclassification errors (false positives and false negatives) in the detection of lumbar instability. 109 patients (57 asymptomatic, 52 symptomatic) were consented in the prospective investigation. The research was designed to compare studies involving FE to controlled motion bending radiographs (CCBR) using the Vertebral Motion Analysis (VMA) within the same patient. Measurement variability was determined by the mean and standard deviation of intervertebral rotation when evaluated by 9 independent observers evaluating each of the 109 patients FE and CCBR. The resulting standard deviation of the intervertebral rotation determinations was used as the measure of variability. Sensitivity (true positive rate) and specificity (true negative rate), were constructed using asymptomatic individuals and symptomatic patients in order to determine true positive (TP) and true negative (TN) appointments. The analysis was compared to known threshold of 25° (IVR) to determine the rates of false negatives (FN) and false positive (FP) rates. Sensitivity and specificity were calculated as TP/(TP/FN) and TN/(FP+TN), respectively. There was statistical greater measurement variability in intervertebral rotation in FE when compared to CCBR (both standing and lying). When comparing measurement variability between FE and CCBR, results indicate between a 26% to 46% decrease in measurement variability under CCBR compared to FE. These findings are consistent across asymptomatic and symptomatic patients. Sensitivity measures were 6.2% (VMA 12.6%, FE 6.4%) greater in the VMA test compared to the FE. Specificity measures were 8.4% (VMA 99.1%, FE 90.7%) greater in the VMA test compared to the FE. The current standard of care for functional testing of the lumbar spine utilizes uncontrolled FE with a manual data evaluation process. Recent developments in using computerized imaging processes has improved, however there remains variability in patient bending due to the self-selected rate and position of the bending. CCBR results in a significant reduction in measurement variability of intervertebral rotation measurements. Reducing measurement variability would be expected to improve the efficacy rates of surgeries indicated for these conditions.
The effects of position and size of drywall on the physical demands for installers
Authors: Yuan Lu , Buchholz Bryan
Published: October 2014

The present study utilized an integrated biomechanical modeling approach that was previously developed by the researchers to investigate the effects of position and size of drywall on the physical demands for drywall installers. If the drywall sheets were stored vertically instead of flat, it reduced the required muscle contraction forces and joint reaction forces at the low back and shoulder approximately 8% on average during drywall installation. In particular, the L4/L5 disc compression forces and the absolute values of L4/L5 anterior-posterior shear forces decreased 6.1% and 8.5%, respectively, and at the shoulder during lifting the forces of rotator cuff muscles decreased 9.8%, and the coracohumeral ligament forces decreased 12.8%. The reaction forces at both the GH (glenohumeral) and SC (sternoclavicular) joints were reduced 7.2% and 3.6%, respectively. The larger size (e.g., 4x12 and 4x16) of drywall sheets increased the physical burden for the installers tremendously and could expose them to a higher risk of musculoskeletal injuries and disorders. In some simulations the average low back lateral shear forces increased to 1675 N and 2152 N, respectively. These forces are well above the 1000 N recommended for a single lift. These results indicated that it would be physically too difficult or even impossible for one person alone to lift bigger and heavier drywall sheets. Therefore, sound engineering (e.g., lifting tables) and/or administrative (e.g., two-person team work) solutions to handling oversized drywall sheets are strongly recommended.
The influence of hand load on lumbar-pelvic coordination during lifting task
Authors: Hu Boyi , Ning Xiaopeng , Nussbaum Maury A.
Published: October 2014

Manual material handling (MMH) tasks such as weight lifting are very common in many industries. The effect of hand load on lumbar-pelvic continuous relative phase (CRP) coordination during lifting was investigated in this study. Twelve male subjects performed sagittal symmetric lifting tasks with or without load in hand; meanwhile lumbar kinematics data were recorded. Results of the current study demonstrated a significant difference of lumbar-pelvic coordination between the two conditions. Subjects tended to show more in-phase CRP pattern when lifting a load. Also, when lifting a load subjects’ lumbar-pelvic motion pattern made their torso generated larger loading on the L5/S1 joint. The findings of this study can be used to better understand how hand load influences lifting biomechanics.
Effects of Seated Whole Body Vibration Exposure on Repetitive Asymmetric Lifting Tasks
Authors: Mehta J.P. , Lavender S.A. , Jagacinski R.J. , Sommerich C.M.
Published: October 2014

This study investigated physiological and behavioral changes to 60 minutes of repetitive asymmetric lifting activity after exposure to whole body vibrations (WBV). Our results demonstrated that behavioral changes when liftinSg after exposure to WBV would increase the risk of low back disorder.
Critical Analyses of Work-related Musculoskeletal Disorders and Practical Solutions in Construction
Authors: Choi Sang D. , Yuan Lu , Borchardt James G.
Published: October 2014

This study reviews and synthesizes the findings in recent literature addressing work-related musculoskeletal injuries and disorders (MSDs) and practical solutions in the construction industry. Seven construction occupations (carpenters, masons, electricians, sheet metal workers, roofers, ironworkers, plumbers) are included to identify trade-related MSD risk factors. Effective intervention requirements are identified to meet the challenges that construction contractors face in the field. Typical intervention strategies include site-specific ergonomics programs, engineering controls, ergonomic hand tools selection/design, and worksite stretching program. The “good practices” presented in this paper could be a valuable approach to reducing common MSDs including sprains and strains, pain and discomfort at back, neck/shoulders, wrists/hands, and knees, improving worker morale, lowering workers’ compensation costs, while increasing productivity and profitability in the construction industry.
Biomechanical Evaluation of a Lift Assist Device while Using a Light Weight Jackhamer
Authors: Johnson Blake , Campbell-Kyureghyan Naira
Published: October 2014

There are currently relatively few interventions designed to decrease the risk of injury while operating a jackhammer. One intervention that is aimed at reducing the risks of overexertion and repetitive lifting injury is the lift assist attachment. However, research on the effectiveness of this device is non-existent. This study investigated the effectiveness of the lift assist device through the muscle activity and grip pressure variations while using a light weight jackhammer. The lift assist reduced grip pressure by 31%, along with the left and right Bicep Brachii muscle activity by 49% and 45% respectively. These results show that the effort required to lift the jackhammer is being reduced through the use of the lift assist. With less effort required by the operator, the risk of an overexertion or repetitive lifting injury is decreased.
Aging, Obesity and Beyond
Authors: Maikala Rammohan V. , Cavuoto Lora A. , Maynard Wayne S. , Fox Robert R. , Lin Jia-Hua , Liu Jian , Lavallière Martin
Published: October 2014

The aging workforce, increase in obesity, and lack of exercise and physical activity are changing the landscape of work environments in the industrialized world. The goal of this panel is to make ergonomics and safety professionals aware of the importance of examining health and wellness issues, aging, obesity, and other modifiable health risks pertaining to occupational health. The first of seven presentations will cover an evidence based wellness continuum that describes specific factors that can motivate healthy work environments. The second presentation discusses the challenges and implications of the aging workforce with emphasis on the role of ergonomics in maintaining health, wellness and working contributions of the aging workforce. In general, muscle mass and muscle strength decrease with age, however the third presentation examines if such age-associated changes are evident during one-handed isometric pulling. Stratifying injury risk in overweight and obese populations is still a challenging endeavor. The fourth presentation demonstrates the biomechanical consequences of gait (a)symmetry due to being overweight and the risk of falling. There is an increasing evidence of obesity influencing every organ system adversely in the human body, including the brain. The fifth presentation examines the association between work performance of obese and non-obese individuals during incremental repetitive lifting and change in their cerebral hemodynamics and cardiorespiratory responses. An interaction between aging and obesity in addressing the risk for involvement in a motor vehicle crash is discussed in the sixth presentation. The final presentation focuses on understanding the integrated efforts of physiological systems such as respiratory, cardiovascular, and skeletal muscle within the context of aging, obesity and physical activity.
Joint Kinetics While Walking on an Irregular Sloped Surface
Authors: Wade Chip , Breloff Scott P. , Redfern Mark S. , Andres Bob O.
Published: October 2014

Occupations, such as railroad work, which requires the worker to perform job functions on irregular surfaces are physically taxing. Previous research and epidemiology have suggested a potential link between walking surface characteristics and injury. However, to date few studies have investigated the impact of irregular surfaces, flat or sloped, on gait dynamics. The current study investigated gait dynamics on a sloped irregular surface in twenty healthy adult men. The participants walked along 2 distinct sloped surfaces [No Ballast (NB), and Mainline Ballast (MB)]. Lower body motion, ground reaction forces, and electromyographic (EMG) signals from lower extremity muscles were collected. Three dimensional joint moments were calculated at the hip, knee and ankle during the down slope step on the walking surfaces. Parameters of interest were moment ranges. Results showed joint moment ranges were generally larger for MB compared to that of NB in the down slope leg. The results suggested walking on ballast increases joint moments at the ankle and knee of the down slope leg during walking on an irregular sloped surface.
Using Eye-Tracking to Investigate Strategy and Performance of Expert and Novice Control Room Operators
Authors: Koffskey Christina , Ikuma Laura H. , Harvey Craig , Aghazadeh Fereydoun
Published: October 2014

The strategies of expert and novice petrochemical control room operators were investigated using eye-tracking as they monitored and corrected a crude refinement simulation. Plotted scan paths were used to investigate the differences in eye behavior of three expert control room operators and six novice students. The effects of expertise and interface type on participant eye movements were evaluated. Scan path analysis revealed that monitoring strategy and interface type influenced how quickly participants were able to detect changes on-screen, though monitoring strategy did not depend on expertise level. Overall, eye-tracking successfully identified the effects of monitoring strategy and interface type on performance.
Potential for using Smartphone Accelerometers in Non-laboratory Environments
Authors: Soangra Rahul , Lockhart Thurmon E. , Frames Christopher W. , Zhang Jian , Moon Seong Hyun , Park Jongsoon
Published: October 2014

In recent years, there has been rising interest in using accelerometers as an alternative instrument to measure the center of pressure. Accelerometers are inexpensive, small, sensitive, and can be readily used in non-laboratory environments. In addition to this, smartphones with built-in accelerometers add to their capability with real-time processing of data from sensors. Clinicians and researchers are currently in disagreement from whether these measurements provide the same physiological information about the participant’s balance. In this study, twelve participants were asked to wear smartphone on their right ASIS using a belt clip and stand still on the forceplate. The data was synchronized using a tap by the right foot and collected over a fifty second period for analysis. Various linear and non-linear measures were extracted from the time series of resultant principal component (PC) scores. The results show high correlation in the COP time series from the two instruments (R=0.86).
Highly automated driving with a decoupled steering wheel
Authors: Kerschbaum Philipp , Lorenz Lutz , Bengler Klaus
Published: October 2014

Future cars will almost certainly provide an increasing level of automation. Under certain conditions, they will allow the driver to withdraw from the control loop and deal with non-driving related tasks. To provide a convenient and safe user interface for this case, it can be advantageous to have the steering wheel de-coupled from the steering link and stationary. In this study, we evaluated two alternative steering wheel concepts. The first concept represents a state of the art steering wheel that decouples from the steering link and remains stationary at an angle of 0° during highly automated driving. In the second concept, the steering wheel shows the same behavior but does not have visible spokes. Hence, it does not display its physical orientation to the driver. Using a dynamic driving simulator, we evaluated the concepts in a comparison drive and a take-over scenario in a curve. A permanently coupled state of the art steering wheel served as control condition. Results show that the decoupling was only noticed by a small number of participants. Further, no negative impacts on the take-over process could be determined. The steering wheel with no visible spokes led to an even better performance compared to the control condition.
Determining Language for Human to Robot Navigational Commands
Authors: G. Teo , L. Reinerman-Jones , D. Barber , I. Hudson
Published: October 2014

Robots that collaborate with humans must be equipped with interfaces that support deeper and richer interaction. Such interfaces may involve the understanding and production of speech. This calls for an understanding of speech and natural language in various contexts. The present study investigates the preferred words and phrases used in giving directions to a robot teammate in an intelligence and surveillance reconnaissance (ISR) mission. Results indicate that participants may have had a perceptual mental model that influenced choice of words or phrases. Recommendations for future research include examining the factors that affect development of schemas when interacting with robots.
Vibrotactile Stimuli Parameters on Detection Reaction Times
Authors: Chancey Eric T. , Brill J. Christopher , Sitz Adam , Schmuntzsch Ulrike , Bliss James P.
Published: October 2014

Signaling system designers are leveraging the tactile modality to create alarms, alerts, and warnings. The purpose of this research was to map detection reaction times (RT) toward tactile stimuli with various parameter manipulations. We employed a 3 (wave form) × 3 (inter-pulse interval) × 3 (envelope) within subjects design. The dependent measure was detection RT. Twenty participants (15 female) responded to 270 tactile stimuli. ANOVAs indicated three two-way interactions. Generally, shorter inter-pulse intervals led to quicker RT and the fade-in envelope led to longer RT, when compared to envelopes starting at the maximum amplitude. Square and sinusoidal waves tended to prompt quicker RT than the noise wave. The strength of these relationships, however, depended upon the presence of the other parameters. Designers can use the results of this study to effectively and appropriately assign tactile parameter manipulations to signals that require varied levels of response urgencies.