bluuebunny/crossref_metadata_2025 huggingface dataset:
Focused Learning
Authors: Robinson Tom , Burns Catherine
Published: October 2013

Increasingly, students learn to use computer-based tools to support their coursework in science, engineering, technology, and mathematics (STEM) courses. A common educational strategy is to introduce the new tool along with new course material, having students learn the tool and the course material simultaneously. We looked at how two simultaneous learning goals affect students’ learning of a computer algebra system (CAS), a tool increasingly used in STEM education. The study described involved teaching a group of students some basic CAS commands through one of two sets of instructional materials that used different contextual examples, based on either familiar or unfamiliar mathematics, which theoretically, based on predictions of cognitive load theory, imposed different levels of cognitive load. The students’ learning of the CAS concepts was tested and their workload during learning and testing was measured. We showed that the students in the familiar math case performed better on a test of CAS concepts and that they reported a lower workload when completing the test. This result was consistent with the predictions of cognitive load theory. The results of this study point to the potential importance of managing the cognitive load of instructional material when training students in the use of advanced educational software systems.
Classroom Design and Student Engagement
Authors: Sanders Martha J.
Published: October 2013

Student engagement is fundamental to a learner-centered curriculum across the United States. This study examined behavioral, cognitive, and emotional aspects of student engagement as related to classroom design in 189 health science students in four different courses. Measures of student engagement in two sections of the same class were compared according to classroom space design: grouped tables or traditional rows. Results indicated that students in lecture-based classes showed higher cognitive engagement in classrooms organized in traditional rows, whereas students in group-focused classes showed higher cognitive engagement in classroom space organized around grouped tables. Results did not support the current belief that innovative seating improves student engagement across all contexts. The relationship between student engagement and classroom design must be considered along with class format and learning objectives.
Characterization of Pulling Forces Exerted by Primary School Children While Carrying Trolley Bags
Authors: Pau Massimiliano , Leban Bruno , Paderi Maurizio , Nussbaum Maury A.
Published: October 2013

Carriage of school items by children remains an issue of concern, mainly due to the large loads they have to bear, starting from early age when the musculoskeletal structure is still under development. As such, children are potentially exposed to important risks of acute or chronic injuries due to such carriage. While backpack remains the most common modality, in recent years trolley bags are increasingly considered and used. Trolleys may be of benefit, as much of the load can supported by the ground, and the muscular effort is limited to a pulling force. Nevertheless, there are situations (like stair ascent and descent, steps, and ramps) where the pulling force increases or, in some cases, has to be fully supported by a single arm. Under such conditions, the use of trolley bag might be disadvantageous versus a backpack, in that the latter allows a symmetrical distribution of the load on the body in a range of conditions. To provide more empirical evidence, which at present is very limited, this study aimed to characterize the pulling forces needed when using a school trolley bag, on a route that includes level and inclined ground surface, steps, and stairs. A sample of 195 students of primary school (age 8-11) participated, and they were asked to pull an instrumented trolley loaded with school items (total load = 62 N) from the school entrance to a classroom located one floor up in the school building. The results, expressed in terms of “pulling force vs. time” curves, show that particularly during stairs ascent and descent, one arm may exert quite large dynamic forces, and that these forces can be up to twice the mass of the carried load. Although exposure to such loads is quite limited, the methodology described here highlights the potential for concern and provides a basis for future investigations of the contribution of trolley bag carriage and disorders of the arm-shoulder complex among children.
Stairway Step Dimensions
Authors: Hicks Christopher L. , Jensen Roger C. , Adams Joselynn M.
Published: October 2013

This paper reports a replication of a prior measurement system study. The earlier study examined the nosing-to-nosing measurement system for measuring steps in a stairway to determine uniformity. In each study, two individuals measured six flights of stairs on two separate occasions. The difference in the first and second study was the different measurers. Step attributes used to define uniformity are riser height and tread depth. The measurers in each study obtained 744 values of riser height and 672 values of tread depth. The ANOVA for each study indicated that less than 4% of the variance in these attributes was due to the measurers; the remainder of variability was due to physical differences in the steps. ANOVA results of this replication led to essentially the same conclusion as the initial study—that the nosing-to-nosing measurement system is acceptable for measuring step dimensions.
A False Sense of Security
Authors: Runge Kevin , Vredenburgh Alison G.
Published: October 2013

Roofing is a dangerous business in any capacity. The following is a case study presenting the dangers of working on a flat roof with parapet walls. A key issue is the workers’ situation awareness of their jobsite while being attentive to their task demands. This case addresses the role of perceptions, safety meetings, trip hazards, barriers and how different subcontractors affect each other’s safety as methods to address this hazard.
Animated Computer Graphics
Authors: Sloan Gary D. , Cohen Joshua , Syverson Jay
Published: October 2013

Human factors safety and forensic professionals are often tasked with inspecting a scene where an accident or injury occurred. Retelling a story accurately and in a compelling way, without a visual context, is challenging. Three-dimensional computer modeling is a tool that some human factors professionals are utilizing to assist in their practice. The goal of the alternate format session is to demonstrate how this technology can be beneficial to human factor (HF) professionals. In addition, the session will emphasize the need for collaboration between HF practitioners and visual media professionals whose skill sets embrace computer graphics and animation. Two such professionals have accepted invitations to participate in the session. Both have earned acclaim as innovators, which will be supported by the content of their respective presentations.
Globalization of Ergonomics - Panel Summary
Authors: Smith Thomas J.
Published: October 2013

The purpose of this panel is to highlight key milestones in the globalization of ergonomics in the modern era. The past six decades have seen the emergence of human factors/ergonomics (HF/E) from a nascent, largely unrecognized field of study to a well-established human science discipline with global reach. Key milestones include: (1) emergence of ergonomics science in Europe; (2) establishment of national ergonomics societies in a growing number of countries; (3) recognition of the view that ergonomics and human factors share common scientific goals and aspirations; (4) establishment of ergonomics programs in a number of large corporations in the post–World War II era; (5) founding of a growing number of scientific HF/E journals; (6) introduction of ergonomics into developing countries; (7) establishment of common standards for both ergonomics education and certification of professional ergonomists; and (8) the ongoing telecommunications revolution, supporting a worldwide community of HF/E professionals. Panel members will provide perspectives on a selected number of these key issues.
General Methods for Communicating the Structure and Content of a Cognitive Model
Authors: Warwick Walter , Lebiere Christian , Jones Randolph M. , Reitter David , Rodgers Stuart , Douglas Scott A.
Published: October 2013

The modeling and simulation of human performance forces the analyst to confront a range of well-known but difficult challenges. One challenge the analyst does not seem to face is a shortage of human performance modeling tools. But because there is no uniform framework for expressing the content and structure of a human performance model, it is difficult to understand what is at stake in the implementation of a given model and all but impossible to compare and contrast different models despite the proliferation of quantitative modeling tools. The inability to communicate model structure and content is not just a practical shortcoming: it is a major impediment to assessing the validity, plausibility, and extensibility of human performance models. The latter aspect is particularly important as it prevents the incremental construction of large human performance models along standard software engineering practices. The goal of this panel discussion is to review past and ongoing efforts to develop general languages that specify cognitive models at a functional level of description. We do not expect a standard to emerge from this discussion, but rather we hope to canvass both the theoretical and practical issues that confront any attempt to develop a uniform language that describes different modeling frameworks.
A Tribute to Bentzi Karsh
Authors: Carayon Pascale , Kleiner Brian , Robertson Michelle , Weinger Matt , Wetterneck Tosha , Holden Rich , Rodriguez Joy , Montague Enid
Published: October 2013

The objective of this session is to display the range of contributions to human factors research and education by Professor Bentzi Karsh who passed away too early in August 2012. The session will consist of a series of presentations by colleagues and students of Professor Karsh to highlight his deep and broad contributions.
Actively Guided Practice Enhances Kinesthetic Memory Development
Authors: Stone Richard T.
Published: October 2013

In traditional weld training novice students often have their hands guided by their instructor, however due to class ratios this kind of guidance is very limited in traditional training scenarios. The aim of this study was to investigate the effectiveness of providing automated movement guidance similar to that which would be provided by a master instructor. The author hypothesized that such a system would in enhancing kinesthetic memory development and by so doing increase student performance. Sixteen welding students participated in this study. These students were trained to weld under different protocols: free-hand (traditional group) and guided (machine group). The tradition group was trained by a certified welding inspector and given physical guidance intermittently. In the machine group, participants were given guidance via a kinesthetic weld trainer (KWT) (designed by the author) that required participants to actively repeat a specific welding angle and speed. The results showed with such guidance, performance and the ability to control the speed with which a weld was made were significantly improved.
Examining Text Enhancement Methods to Improve Look-alike Drug Name Differentiation Accuracy
Authors: Or Calvin K. L. , Wang Heller H. L.
Published: October 2013

The current study examined the use of several text enhancement methods with the aim of improving the accuracy of differentiating between confusing look-alike drug names. It also evaluated the influence of orthographic similarity. Although Tall Man (uppercase) lettering is recommended as a means of improving such differentiation, studies have produced mixed results on its efficacy, with other typographic styles suggested as potential alternatives. In the present study, university students (n = 40) participated in a differentiation task in which they were asked to determine whether the two drug names in each of 336 potentially confusing name pairs were the same or different. Accuracy (the proportion of correct responses) was the study outcome. The experiment adopted a two-way, within-subjects factorial design, the factors being text enhancement (Tall Man, boldface, boldface+Tall Man, colored text (red), and contrast and a lowercase control) and orthographic similarity (low, medium, and high degrees of similarity). The results showed text enhancement, orthographic similarity, and the interaction term to have significant main effects. The accuracy of each of the five text enhancement conditions was significantly greater than that of the lowercase control, and, relative to Tall Man lettering, all of the other text enhancement methods produced significantly higher degrees of accuracy. With regard to orthographic similarity, a high degree of similarity yielded the least accuracy, followed by medium and low degrees. Highlighting the primary dissimilarities between confusing drug name pairs using text enhancement methods clearly makes the names easier to differentiate, although Tall man lettering may not be the most effective such method. The results of this study demonstrate that other typographic styles have greater potential to render confusing look-alike names more visually distinct and to reduce confusion errors.
The Impact of New Instruments on Surgical Performance in Natural Orifice Translumenal Endoscopic Surgery
Authors: Chellali Amine , Cao Caroline G.L.
Published: October 2013

Natural Orifice Translumenal Endoscopic Surgery (NOTES) is a recent emerging technique for performing general surgery procedures such as cholecystectomy (gallbladder removal). However, the advantages of NOTES over conventional laparoscopic surgery, the current gold standard, are still questionable. The aim of this study was to show the impact of introducing new surgical instruments in the NOTES technique on surgical performance in a cholecystectomy as compared to conventional laparoscopic surgery. A set of videos from real cholecystectomy cases performed using these two different techniques were analyzed. Hierarchical task decomposition and timeline analysis were conducted for each technique. A comparison to show variations between the two techniques at the task level is presented to highlight the technical issues, and their effects on performance, associated with the use of current endoscopic tools in the NOTES technique. The results show a longer procedural time in the NOTES technique than in the laparoscopic technique with the highest increase in surgical time for dissection tasks. The tools used for dissection were also shown to be inadequate for the task based on the motion analysis. Using this systematic method of analysis, new surgical techniques can be assessed based on performance measures, while areas of design improvement in surgical tools can be identified and related to the performance assessment.
Characterization of the Learning Plateau and the Learning Rate of the VBlaST PT© Simulator with a Kinematic Objective Performance Metric
Authors: Sankaranarayanan Ganesh , De Suvranu , Cao Caroline G.L.
Published: October 2013

Gaining proficiency in laparoscopic surgery requires a considerable amount of practice. The VBLaST© is a virtual reality simulator that can simulate the Fundamentals of Laparoscopic Surgery (FLS) tasks. It is equipped to compute and record scores automatically along with kinematic parameters such as path length, economy of motion, motion smoothness, etc. In this study the learning curve for the VBLaST PT© simulator was characterized from both the computed numerical score and the path lengths of the left and right tools. From the learning curve, the learning plateau and the learning rate was also found for both parameters. A total of 6 subjects participated in the learning curve study that consisted of 15 sessions of 10 repetitions of the peg transfer task for a total of 150 repetitions in three weeks. Subjects performed better in terms of higher scores and shorter path lengths within the first practice session but improved their performance thereafter and achieved a stable plateau. Paired sampled t-test on the pre, post and retention tests showed significant learning retention for both metrics. Tool path length is a valid kinematic metric that can be used to assess the learning and retention of laparoscopic surgical skill along with the numerical score computed from completion time and errors.
How Surgical Robotics Transform the Development of Expertise in Modern Operating Rooms
Authors: Balkin E. Asher
Published: October 2013

Current models of the clinical surgical process, and as a result, surgical education, present robot-assisted surgery (RAS)1 as a simple sequential step in the evolution of surgical treatment from laparoscopy. In an ongoing research program on robot-assisted surgery this paper presents data from the first, ethnographic, research phase demonstrating that the requisite skills for success in the robot-assisted environment are altered from those expected within the laparoscopic domain, and as a result, the training paths and novice-to-expert progression trajectories are noticeably dissimilar.
Identifying, Developing, and Quantifying Single-Day Quality Measures within the Neonatal ICU
Authors: Lu Sara A. , Schumacher Robert E. , Nemshak Michelle , Seagull F. Jacob
Published: October 2013

Assessing safety culture, while valuable, may neglect day-to-day variation in the experiences of individual care providers. Understanding day-to-day variation may be a key to understanding and improving the single-day quality (SDQ) of care providers. The goal of this study was to: (1) determine the variables that contribute to the quality of each day (SDQ), (2) determine the validity and perceived importance of each contributing variable, and (3) determine how well care providers can predict whether the variables will have an effect on their SDQ. Interviews of NICU nurses and literature reviews were used to identify six variables perceived to influence SDQ. A survey tool assessing the six variables and SDQ was developed. Nurses were then surveyed at the beginning and end of each shift, providing a prospective (pre) and retrospective (post) assessment of all six variables plus an overall SDQ rating. The results identified which variables predicted or contributed to SDQ. Although the predictive power of the six variables differed between prospective and retrospective estimations, environmental factors and patient acuity were consistent contributors to SDQ. Overall, understanding the contributors to day-to-day variation can be used to as means to improve the healthcare provider’s SDQ and the safety of patient care.
Discussion Panel Giving Human Factors/Ergonomics Away
Authors: Klein Martina I. , DeLucia Patricia R. , Doig Alexa , Drews Frank , Durso Francis T. , Miller Anne
Published: October 2013

Patients spend the most time with nurses compared with other health care providers, and patient outcomes are directly related to the quality of nursing care. Unfortunately, nursing work systems are often not designed to accommodate the limits and capabilities of perceptual, cognitive, and physical processes, which can result in errors. The Institute of Medicine estimated that hospital patients experience one medication error each day. Increasingly, technology is relied upon to reduce errors and improve work efficiency. However, new technologies can lead to unintended consequences. Applying principles of human factors and ergonomics (HF/E) to improve nursing work systems and the technologies nurses use has the potential for significant improvements in the quality of patient care. Incorporating HF/E into the nursing domain presents challenges. Conducting research in the nursing environment poses unique logistical issues, and implementing HF/E recommendations requires that nursing personnel accept HF/E as beneficial. The purpose of this panel session is to discuss issues that HF/E professionals encounter when they attempt to incorporate HF/E into the nursing domain. The panelists will summarize the work that they have done with nurses and describe challenges and successes. The panel will invite the audience to discuss ways to address challenges, increase successes, and identify lessons learned in other domains that may benefit nursing.
Human Performance with Multiple Devices Influencing a Single Cursor
Authors: Hughes Stephen , Bardell Cody , Schafer J. Ben
Published: October 2013

The goal of this study is to better understand how collaborative influence upon a single cursor may impact the performance of simple tasks like movement and selection. Two techniques for combining input from multiple devices are compared to an individual controller using a Fitts’s selection task. The results suggest that it is possible for multiple users to collaboratively move a single pointer without significant degradation in performance.
Using Biodata to Select Air Traffic Controllers
Authors: Pierce Linda G. , Broach Dana , Bleckley M. Kathryn , Byrne Cristina L.
Published: October 2013

Biodata factors were examined as predictors of training performance for candidate air traffic control specialists (ATCSs). These factors, which have been shown to predict controller training performance in previous research, were highest educational degree achieved, grade point average both in high school overall and in high school math courses, aviation operations experience, pilot licenses held, and age. Results from logistic regression analyses were only partially supportive of previous research. Age was the most consistent (inverse) predictor of training success. Most of the other factors did not predict training success. Differences between these results and previous research might be attributed to differences in the criterion measures, samples, and generational differences. Overall, the evidence for using the assessed biodata factors for selection was weak. We suggested that a new biodata instrument be developed to assess and identify experiences to predict performance of the next generation of controllers.
The Effect of Positive vs. Negative Emotion on Multitasking
Authors: Morgan Brent , D’Mello Sidney
Published: October 2013

Emotions have been shown to affect cognition and performance on a multitude of individual tasks; however, people increasingly choose (or are required) to perform multiple tasks simultaneously (multitask1). How, then, do emotions affect multitasking performance? This question was assessed in an experiment wherein participants first multitasked in a Baseline phase, watched a video designed to induce a positive, neutral, or negative emotion, and then resumed multitasking for two additional phases. The results indicated that both the positive and neutral video conditions were superior to the negative condition; however, a marginally significant interaction indicated that the neutral condition was equivalent to negative at the final multitasking phase. We conclude by discussing the theoretical and applied aspects of these findings.
Individual Differences in Movements in Response to Natural Disasters
Authors: Helton William S. , Kemp Simon , Walton Darren
Published: October 2013

Natural disasters requiring travel to safety include hurricanes, wildfires, floods, earthquakes, and tsunamis. Computational models and agent-based simulations of disaster evacuation and travel behavior have been developed to help disaster planners; however, these models may entail unrealistic assumptions regarding uniform human behavior. Many of these models assume people travel immediately after a disaster notification and that people travel straight out of the area likely to be affected. The present study provides two examples from Christchurch, New Zealand: a small scale but detailed measure of travel behavior after a real tsunami warning was issued and a larger scale study of self-report of considerations of leaving the city after a major local earthquake. In the tsunami study, 15% of the people actually moved towards the tsunami risk zones, not away. In the second study only 11.7% of the 206 people surveyed indicated thinking of leaving the city and they were significantly more likely to be female and high in trait neuroticism. Individual differences in responses to natural disasters need to be considered in disaster travel models.
The Effect of Individual Differences on How People Handle Interruptions
Authors: Meys Hilkka L. , Sanderson Penelope M.
Published: October 2013

Some people handle interrupting and distracting events better than others, but it is not clear how to predict this. We hypothesised that when performing a primary ongoing task, people with a field independent cognitive style would be less distracted from their task by interruptions, and less likely to accept interruptions, than people with a field dependent cognitive style. We also hypothesized that when returning to the original task after an interruption, people with high spatial ability would have better memory for the physical location of their original activity, and people with high working memory would have better memory for the factual contents of their original activity. Our study participants performed an arithmetic task that was interrupted at arbitrary moments by a lexical decision task. Results showed that participants with high working memory remembered the location and contents of their original activity faster and more accurately than did participants with low working memory. Field dependence did not predict participants’ willingness to accept interruptions, and spatial ability did not predict how quickly or accurately they returned to the physical location of their original activity. However, the psychometric test instruments we chose may not have been the most appropriate. Our results confirm that working memory plays an important role in helping people recover interruptions and distractions, but further and more precise tests of field dependence and spatial ability are needed.
The interaction of force and repetition on systemic inflammatory cytokine response in a rat model
Authors: Gallagher Sean , Barbe Mary F. , Massicotte Vicky S. , Barr-Gillespie Ann E.
Published: October 2013

In this paper, we describe the effects of force and repetition on systemic inflammatory responses in a voluntary rat model of repetitive reaching and handle pulling. Specifically, we examine the interaction of force and repetition on serum cytokine expression, which we believe may be a response to fatigue failure damage in musculoskeletal tissues. Young adult, Sprague-Dawley rats performed a handle-pulling task for 12 weeks at 4 different repetition and force levels: 1) low repetition with low force (LRLF), 2) low repetition with high force (LRHF), 3) high repetition with low force (HRLF), and 4) high repetition with high force (HRHF). Force x repetition interactions were observed at week 12 for serum cytokines including TNFalpha (p = 0.003), IL-1alpha (p < 0.0001), and IL-1beta (p < 0.0001). The pattern of interaction observed with serum cytokines in this study mirrors the force-repetition interaction observed in epidemiological studies of musculoskeletal disorder risk (Gallagher and Heberger, 2013).
Electromyography & Portable Computing Devices
Authors: Werth Abigail J. , Babski-Reeves Kari
Published: October 2013

Portable computing devices have become more lightweight and mobile due to changes in the hardware of the devices. In many cases, hardware keyboards are being replacing virtual keyboards, raising concerns on changing ergonomic exposures as, for example, muscle activation patterns may vary with virtual keyboard use. The objective was to identify active forearm muscles across select computing devices. Twenty participants completed a single test session in which seven forearm muscles were evaluated using surface EMG whilst they typed on two portable computing devices (netbook and slate computer) for 5 minutes apiece. Mean normalized EMG was analyzed and indicated that slate computers resulted in significantly lower muscle activation levels than netbooks. The extensor carpi radialis, extensor carpi ulnaris, extensor digitorum communis had the highest muscle activation levels for both the slate and netbook computers. This indicates that the same muscles should be studied for both slate and netbook computers.
The Impact of Gender on Personal, Health and Workplace Psychosocial Risk Factors for Carpal Tunnel Syndrome
Authors: Harris-Adamson Carisa , Eisen Ellen A , Dale Ann Marie , Evanoff Bradley , Hegmann Kurt T. , Thiese Matthew S. , Kapellusch Jay , Garg Arun , Burt Susan , Bao Stephen , Silverstein Barbara , Gerr Fred , Merlino Linda , Rempel David
Published: October 2013

Between 2001 and 2010 six research groups conducted coordinated multi-year, prospective studies of upper extremity musculoskeletal disorders in US workers from various industries and collected detailed subjectlevel exposure information with follow-up symptom, physical examination, electrophysiological measures, and job changes. Objective. This analysis of the pooled cohort examined the incidence of dominant-hand carpal tunnel syndrome (CTS) in relation to demographic characteristics and estimated associations with occupational psychosocial factors, adjusting for confounding by personal risk factors. Methods. 3,515 participants, without baseline CTS, were followed up to 7 years. Case criteria included symptoms and an electrodiagnostic study consistent with CTS. Adjusted hazard ratios were estimated in Cox proportional hazard models. Workplace biomechanical factors were collected but not evaluated in this analysis. Results. Females were at elevated, though statistically non-significant, risk for CTS (HR=1.30; 95%CI: 0.98-1.72). The incidence of CTS increased linearly with both age and BMI over most of the observed range. High job strain increased risk (HR=1.86; 95%CI: 1.11-3.14) and social support was protective (HR=0.43; 95%CI: 0.23-0.78). There was no effect modification of gender on age, BMI or high job strain. Conclusions. Personal factors associated with an increased risk of developing CTS were BMI, age and being female, though no effect modification by gender was evident. Workplace risk factors were high job strain while social support was protective.
Neural Mechanisms of Anticipatory Balance Control
Authors: Rodrick David , Jayaprakash Vaishali
Published: October 2013

Anticipatory balance control is complex motor control ability that human use at workplace and other everyday physical activities. This study investigated the neural mechanism of anticipatory postural balance when participants were exposed to controlling upright stance posture in various balance difficulty levels. A total of 15 healthy male participants without any prior history of physical or neurological disorders took part in the study. A Biodex balance system was utilized to perform the balance control task. A 10-20 international system was used to collect EEG data on 19 brain locations. The participants were assigned three upright stance conditions: 1) standing on the balance platform when the platform was completely stable (baseline), 2) balancing on the platform in gradually increasing instability level, and 3) balancing on the platform in gradually increasing the stability level. Each of second and third condition consisted of a 30-second trial. Each channel EEG data was further decomposed into five frequency bands, such as, delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), Beta (12-30 Hz), gamma1 (30-40 Hz) and gamma2 (40-80 Hz). Balance performance showed that anticipatory control of balance was better for condition where balance surface progressively changes from completely stable to relatively stable level compared to progressively changes from completely unstable to relatively unstable level. Brain mechanisms as measured by electroencephalogram (EEG) showed a general pattern of alpha band power decrease and high frequency gamma band power increase between resting and task condition.
The Influence of Foot Sizes on Human Balance
Authors: Qiu Hai , Xiong Shuping
Published: October 2013

This study investigated the relationship between foot size and human balance performance. The balance performances of 30 female subjects (15 young, 15 elderly) were assessed by a force platform system. Mean sway velocity, balance strategy score and composite equilibrium score (CES) were used to quantify balance performances from three different aspects. Correlation analysis was conducted to analyze the relationship between foot sizes and human balance measures. The results showed that most foot size measures (with or without normalizations) have significant correlations on mean sway velocity and balance strategy score, but no relationship with CES. In general, the bigger the foot size, the lower mean sway velocity and the bigger the normalized foot size, the higher balance strategy score (more ankle strategy), especially for the young group.
Age-Related Changes in Trunk and Knee Kinematics During Lifting
Authors: Song Jiahong , Qu Xingda
Published: October 2013

This study examined the trunk and knee joint kinematics of younger and older people in lifting tasks. Five younger (20-26 years) and six older (58-70 years) participants performed a series of lifting tasks with different load weights in the sagittal plane. The angular displacements, velocities and accelerations of the lumbar spine and knee joint were calculated and analyzed to determine the age-related differences. The results showed the older participants had significantly decreased angular displacements, velocities and accelerations at lumbar spine and knee joint, and preferred a lifting strategy closer to stoop lifting compared with the younger participants. The age-related distinctions in the lifting strategy may result in increased risks of instability and low back pain for older workers during lifting tasks.
Can Electroencephalogram (EEG) Signals Predict Postural Balance Performance?
Authors: Rodrick David , Malik Hafiz
Published: October 2013

Although it is argued that EEG signals lack sufficient signal-to-noise ratio, bandwidth, and information content to decode body segment kinematics (Lebedev and Nicolelis, 2006), this pilot study examined the feasibility of decoding lower extremity postural balance kinematics (i.e., anterior-posterior [A-P] and medial-lateral [M-L] deviation) utilizing EEG signals with reasonable accuracy. The study utilized single trial data of 5 participants that completed a postural balance task on a Biodex balance system when balance platform was set at a relatively unstable level. The neural response during the balance task was collected for 19 sites on the scalp. The time series data of 26 cortical locations were calculated. Following velocity calculation, resampling, and smoothing of the data, a linear decoding method was followed for both scalp and cortex data that utilized a fixed lag of 100 milliseconds and 10×10 fold cross validation procedure. Decoding accuracy was measured by estimating the correlation coefficient between measured and model reconstructed velocities. The average correlation coefficient (standard deviation in parenthesis) using scalp EEG signals was 0.356 (0.218) and 0.41 (0.179) for A-P and M-L velocities, respectively. The average correlation using localized cortical time series was 0.396 (0.238) and 0.458 (0.175) for A-P and M-L velocities, respectively. The findings were argued to be reasonably promising compared to other recent findings.
The Effects of Obesity and Workload on Hand Grip Endurance
Authors: Cavuoto Lora A. , Mehta Ranjana K.
Published: October 2013

The present study examined the relationship between obesity and workload on hand grip strength and endurance. Twenty-two participants (11 non-obese and 11 obese) attended four experimental sessions, each session involving hand grip strength testing and sustained endurance task at a specified relative workload level (20, 40, 60, and 80% of maximum voluntary contraction (MVC)). Dependent measures included absolute hand grip strength, endurance time, and rate of strength loss. Results indicated that obesity was associated with higher absolute hand grip strength and faster rate of strength loss during the endurance task. Additionally, shorter endurance times were observed for the obese group (~26-53% reduction from non-obese group) during the higher workload tasks in both males and females. Findings from this study suggest that obesity impairs hand grip fatigability, and that this relationship is augmented at higher workload levels.
Biomechanical differences between obese and healthy-weight workers in manual materials handling
Authors: Corbeil Philippe , Plamondon André , Teasdale Normand , Handrigan Grant
Published: October 2013

The objective of this study was to evaluate the work strategies of obese and healthy-weight workers in manual materials handling. Seventeen obese and 20 healthy-weight manual materials handlers participated in this laboratory study. The tasks consisted of transferring four boxes between a hand trolley and a conveyor. The weight of the box (15 vs. 23 kg), the handling height and the working configuration were modified to see what impact these changes had on the participants’ manual materials handling. Biomechanical measures included net moments, expressed in the pelvic system (flexion–extension, lateral bending and torsion moments), kinematics of body segments and box displacements. The results indicated that trunk and knee postures and horizontal hand distances from L5/S1 were not significantly different between the two groups. Peak moments of force around the transverse, sagittal and longitudinal axes at L5/S1 were 13.3% to 59.0% higher during box lifting and lowering for the obese than for the non-obese workers. The individuals’ body weight explained 57% of the variability in the maximal transverse moments of force at L5/S1 during the lifting of the boxes from the ground. These results suggest that the extra mass of an obese worker causes additional stress for the musculoskeletal structures of the back. These biomechanical differences potentially place obese workers at a greater risk of developing musculoskeletal problems during manual materials handling.
Quantification of the Physical Demands for Servers in Restaurants
Authors: Wills Angela C , Davis Kermit G , Kotowski Susan E.
Published: October 2013

Serving staff are an integral part of restaurant establishments. Although over 2.2 million individuals are employed as wait staff in the US and experience a considerable number of musculoskeletal disorders each year, little is known about their work-related risk factors for MSDs. Using observational methods, a physical activity monitor, and surveys, this study quantified the physical demands experienced by servers over a shift. Twenty wait staff were evaluated for postures used during serving, tray weight, pain symptoms, and perceived workload. Results showed increases (upwards of 60%) in pain throughout their shift, substabtial time spent standing or walking (~75%), and potentially risky arm/wrist postures during serving, even though a majority of servers indicated lighter than normal workloads during the observation period. While further research is needed, this study provides a first glimpse at the physical demands experienced by wait staff.
Placement of Call to Action Buttons for Higher Website Conversion and Acquisition
Authors: Hernandez Ania , Resnick Marc L.
Published: October 2013

Online shopping abandonment is often a sign that consumers failed to achieve their objectives, which often leads to frustration and reduced brand engagement. Several visual scan path patterns are presented to represent different user activities. For landing pages, it is proposed that the Gutenberg pattern is the most effective at supporting customer shopping needs. A series of tests using eye tracking and qualitative page evaluation confirmed this hypothesis. Across over a hundred web sites from a variety of sectors and industries, landing pages that support the use of the Gutenberg pattern consistently showed simpler user scan paths and more user fixations and clicks-through on the Add to Cart button.
Designing sustainable work systems in a globalized world
Authors: Zink Klaus J.
Published: October 2013

There is a growing discussion about sustainability in society which is now also extending to a company and work system level. More and more customers are interested where their products are coming from and under which conditions they have been produced. Burning textile factories in Asian countries as only one example are of increasing public interest. Therefore, companies have to take care about the whole supply chain but also the whole life cycle perspective of their products. Looking at this situation this paper asks the question whether human factors or ergonomics can contribute to find solutions for these problems. Is the perspective of macro-ergonomics or systems-ergonomics broad enough to include such questions? Do we need new instruments and additional knowledge to be able to contribute to solutions?
Improving Perceived Fairness of Task Assignments in Cardiovascular Intensive Nursing Care Unit with Simple Queuing Mechanism
Authors: Saffarian M. , Giang W.
Published: October 2013

In this work, a simple computer application is proposed to improve the perceived fairness of Cardiovascular Intensive Care Unit (CVICU) nursing team in hospitals. The proposed system called Intensive care Unit (ICU) Task Assignment Platform (ICU-TAP) is aimed to increase perceived fairness and satisfaction through a systematic but flexible scheduling method. The solution proposed here takes into account the skill preference of each nurse to ensure an equal opportunity to maintain career goals, with an aim to increasing job satisfaction. The system is designed based on the basic concept of queuing. ICU-TAP equally distributes the harder and monotonic tasks among nurses and takes into account the desired skill of each nurse for more frequent assignment of other tasks. The proposed system is expected to make the workflow of the unit traceable, resulting in paperless scheduling, and reducing discrepancies between scheduling and daily task assignment of the nursing unit.
Ergonomics Practice in Nigeria Today
Authors: Adaramola S.S
Published: October 2013

There is a growing need in Nigeria to develop ergonomics in all sectors of the economy. This led to the inauguration of Ergonomics Society of Nigeria (ESN) on the 14th of Sept, 2006, in Port Harcourt, Nigeria. The Range of activities undertaken by ESN as at now is not broad coupled with the fact that the society compared with other professional bodies in Nigeria has relatively small number of members. However it is noteworthy that ESN plays a central role in publicizing and promoting ergonomics in the country. In addition: ESN has joined International Ergonomics Association (IEA) as an affiliate society in the third quarter of 2008. As ESN ergonomics activities spread into many areas, it is expected that there will be increase in exchange of information about its activities and about the ways they can address the particular ergonomics related issues found in Nigeria.

Promoting Facilitator roles of ergonomists are increasingly important in responding to growing local needs. As a facilitator for ergonomic action, mobilizing local experience and achievements, development of local research and risk-assessment capacities and production and application of participatory ergonomic training programmes are of particular importance. These requirements will be fulfilled by carefully looking at the life and work of the local people in their own socio-cultural conditions. Ergonomics research and training attempts should be reviewed and examined from the viewpoints of facilitating sustainable action and improvement under local initiative.

“Learning from each other” is an important message conveyed by recent progress of ergonomics in Nigeria. Many ergonomic improvements carried out by local non-expert people at low-cost encouraging examples. These vital experiences are largely applicable to improving working conditions in industrially developing country like Nigeria. International cooperation in the field of ergonomics will facilitate and increases further local action when focusing on exchanging experiences and supporting local initiative.
Detecting Numerical and Waveform Changes on a Head-Mounted Display vs. Monitor
Authors: Tear Callum L. , Fox Mithila , Tsai Matthew , Liu David , Sanderson Penelope M.
Published: October 2013

In this study we investigate whether people timesharing two tasks might perform worse when using an HMD than when using a conventional monitor for one of the tasks. Specifically, we set out to partially replicate and extend Liu et al.’s (2009) findings that anesthesiologists took 60 seconds longer to notice a simulated respiratory waveform change (decrease in waveform frequency) when using an HMD than when using a conventional monitor—a finding consistent with inattentional blindness (IAB). Our study shows that participants using an HMD detect all changes faster, but it also suggests that detecting decreases in waveform frequency might be relatively harder with an HMD than detecting increases. The results suggest future directions to take to investigate the conditions under which participants might not notice changes in an HMD display.
Supporting Speeded Navigational Communication via Gesture-Controlled Vibrotactile Displays
Authors: Roady Trey , Ferris Thomas K.
Published: October 2013

Recent research has shown that haptic displays are particularly well-suited to communicating navigation information, but these displays are rarely evaluated in situations that require time-critical communications. The present study serves as the first proof of concept for “CHIAD”: a new haptic interaction system that allows fast and efficient communication of navigation information by supporting gesture-based encoding of navigational instructions and intuitive decoding of the instructions by mapping them to vibration presentations at different body locations. Participant pairs completed a speeded target-selection navigation task by utilizing three different interfaces: verbal instructions via two-way radio, vibrotactile signals activated by a laptop-based interface, and the CHIAD system. The results show the fastest and most accurate performance with the CHIAD system, suggesting two conclusions: vibrotactile signals are more effective than verbal interactions in supporting speeded communication of simple navigation instructions; and natural gesture methods support faster encoding of instructions.
Imperfect Automation in Scheduling Operator Attention on Control of Multi-Robots
Authors: Chien Shih-Yi , Lewis Michael , Mehrotra Siddharth , Sycara Katia
Published: October 2013

An operator’s workload increases substantially when the operator must control multiple robots and continually shift attention from robot to robot. As the number of robots increases, the amount of time an operator can spend operating any particular robot decreases, which leads to inevitable changes in the robot’s performance. If the robots could self-report encountered faults, the operator could conserve cognitive resources to spend on reasoning about more complex situations. In the reported experiment, participants performed foraging tasks while assisted by an alarmed system, either Open-queue in which all alarms are displayed or SJF-queue (shortest-job-first), whose reliability level was high (90%) or low (50%) under different task load (3-robots vs. 6-robots). The results showed that simply increasing the system reliability might not effectively contribute to the overall performance or the participants’ trust in automation. An inverse relationship was observed between experienced workload and rated trust which also amplified the effects of imperfect automation.