bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing intraoperative teamwork skills at the individual level: From research to implementation
Authors: Yule Steven
Published: October 2012

This paper focuses on observing and rating teamwork skills of each individual member of the team. With training of teamwork skills becoming a central aspect of many medical, nursing and surgical training curriculums all over the world, developing reliable and validated observation scales to assess non-technical skills at the individual level is essential. This paper focuses on the process of developing workable tools, and guidance for researchers who are in the process of tool development. Particular emphasis will be placed on the development, evaluation and application of the NOTSS (Non-Technical Skills for Surgeons) system – an observation tool for assessing individual surgeons’ intraoperative behaviors.
Using Human Factors And Systems Engineering To Improve Care Coordination
Authors: Bisantz Ann M. , Carayon Pascale , Miller Anne , Khunlertkit Adjhaporn , Arbaje Alicia , Xiao Yan
Published: October 2012

The Institute of Medicine (IOM) describes care coordination as one of the six dimensions of health care to overcome barriers and accomplish improvements in the quality of care (IOM, 2001). Care coordination has received more research attention because of its potential to improve the quality and safety of care. Despite numerous efforts to improve care coordination, there is limited evidence regarding their effectiveness and the benefits described vary widely among studies. Moreover, we know little about the specific characteristics of care coordination. In this panel, the speakers will share their experiences regarding (1) barriers to and strategies for effective care coordination, (2) different care coordination mechanisms that affect quality and safety of care, and (3) the use of a human factors engineering approach to understand and improve care coordination. The panel members will use their research experiences and the existing literature to provide a better understanding of different aspects of care coordination and to identify future research directions.
A wealth of information creates a poverty of attention?: Understanding information requirements at handovers
Authors: Wears Robert L. , Parker Sarah Henrickson , Cohen Michael , Carroll John , Perry Shawna , Manser Tanja
Published: October 2012

Given the growing interest in understanding and improving handovers, a deeper understanding of exactly how to create the most effective handover is necessary. This unique symposium will emphasize the distinction between salience and comprehensiveness in handover communications across multiple acute care settings. The discussion panel brings together individuals with experience spanning human factors and system safety research, complex systems, information utilization, public policy, organizational and health communication, and clinical practice to provide a set of diverse but complementary viewpoints on what it will take to successfully, safely, and meaningfully design and implement communication structures for salient information exchange.
Gender Effects on Musculoskeletal Symptoms among Physician Computer Users in Outpatient Diagnostic Clinics
Authors: Hedge Alan , James Tamara
Published: October 2012

A survey of computer use patterns among 179 physicians within multiple outpatient diagnostic clinics of a major healthcare system in the USA showed significant gender effects. A majority of physicians reported daily use of a desk mounted computer. Female physicians spent more time using a computer, were more likely to adjust the keyboard, but felt less familiar with the adjustability features. Over half of respondents reported upper body musculoskeletal discomfort. Female physicians experienced more frequent neck, shoulder, upper back and right hand musculoskeletal discomfort symptoms which seem to relate to their hours of computer use. Implications for the increased use of computers in healthcare are described.
Comparison of Muscle Exertion and Fatigue Between Standard Bag Valve Mask and NuMask
Authors: Riggle Jakeb D. , McCrory Bernadette , Wadman Michael , Miller Emily , Balogh Bobbi , Cao Vincent , Sargus Catherine , Hallbeck M. Susan
Published: October 2012

Ventilation is an important part of cardiopulmonary resuscitation (CPR) performed by medical professionals. The self-inflating bag valve mask (BVM) is often used to deliver rescue breaths during CPR. As resuscitation may last for extended periods of time, it is important that the equipment used reduces the potential of operator fatigue, which could lead to decreased performance and substandard patient care. The NuMask is an intraoral mask designed as an alternative to the pre-inflated mask typically used with a BVM. This pilot study uses muscle exertion electromyography, Borg’s CR10 pain scale, and a Likert-scale questionnaire to compare muscle contraction, fatigue, and user preference between these two interfaces when ventilating a difficult airway mannequin. No significant differences were found in muscle pain or interface preference, but significantly lower muscular exertion by the non-dominant thenar eminence when using the NuMask suggests this interface could reduce user fatigue during extended periods of ventilation. A larger, more conclusive study is necessary to confirm these results.
Ergonomic Aspects of Clinical and Surgical Procedures Discussion Panel Proposal
Authors: Armstrong Thomas J.
Published: October 2012

This discussion panel aims to identify ergonomic concerns, solutions and research needs related to outcomes and the health and safety of workers who perform clinical and surgical procedures. This session will begin with formal presentations to demonstrate current ergonomic concerns and research initiatives associated with clinical and surgical procedures to frame the panel discussion for the second part of the session. Discussion of different procedures will help to identify solutions research needs that relate to a broad range of ergonomic problems. Questions will be collected from the attendees and speakers and organized so as to guide the panel discussion and to engage all of the speakers in the discussion to achieve the symposium aims.
One Size Does Not Fit All: Health Care Human Factors When Designing for an Emerging Market
Authors: Sethumadhavan Arathi , Dove Laura
Published: October 2012

This paper discusses the methodologies that were used to understand the users and the usage environment in an emerging market (i.e., India) and how the findings were used to aid the design of a next generation computer system (referred to as a programmer) that will be used in clinics and hospitals to manage cardiac devices. A variety of techniques including observations, interviews, and story-boarding helped to unravel the key differences in the clinical practices between India and the United States. The main differences between these markets were in the following areas: the exam room environment, transportation of the programmer, familiarity and expertise with the programmer, level of cardiac training, documentation practices, and degree of collaboration during device checks. These findings were used to make recommendations for the product design that could meet the unique needs of Indian clinicians.
An investigation of format modifications on the comprehension of information in consent form when presented on mobile devices
Authors: Madathil Kapil Chalil , Koikkara Reshmi , Dorlette-Paul Melissa , Ranganayakulu Sanjay , Greenstein Joel S. , Gramopadhye Anand K.
Published: October 2012

A major challenge associated with converting paper-based consent to electronic versions is to assure that the level of comprehension offered by the electronic consenting systems is not reduced. A randomized between-subject trial comparing patient comprehension with four different electronic consenting formats of the same consent information presented on an Apple iPad was conducted using a non-clinical sample of 32 participants. The formats were Text-Based, text-based with Text Being Read out, Video-Based and Video-Based with Subtitles. The participants were asked to read and complete a consent form in one of the formats. The participants were subsequently asked to complete a semantic comprehension quiz, the NASA Task Load Index and the computer system usability questionnaire (CSUQ). Upon completing the questionnaires, the participants took part in a retrospective think-aloud session to understand any difficulties they had using the consent forms. Statistically significant differences among the formats were found for task completion time, the mental demand and frustration sub-components of the NASA-TLX, and the comprehension quiz. Video with subtitles to convey consent information appears to be the best format among the formats tested for electronic consent presentation.
Using Videos to Determine the Effect of Stage of Operation and Intraoperative Events on Surgeons’ Intraoperative Leadership
Authors: Parker Sarah Henrickson , Flin Rhona , McKinley Aileen , Yule Steven J.
Published: October 2012

Background Leadership is a key component for the successful functioning of teams and the achievement of task goals. During the intraoperative phase of surgery, the attending surgeon can be likened to a team leader with responsibility for task accomplishment by a small team. This study identified and evaluated surgeons’ leadership behaviors during operations, with particular reference to any changes that occurred following two types of events. Method Videos of live operations ( n=29) from the operating rooms of three teaching hospitals in the UK were analyzed to identify and code surgeons’ intraoperative leadership behaviors using the Surgeons’ Leadership Inventory (SLI). The frequency and quality of the leadership behaviors were compared before and after the point of no return (PONR) (n=24) and before and after an unexpected intraoperative event (n=5). Results Most leadership behaviors were directed toward the resident during an operation. No significant differences were found for the overall frequency or quality of leadership behaviors pre- and post-PONR. The frequency of leadership behaviors classified as ‘training’ and ‘Supporting others’ significantly decreased after an unanticipated intraoperative event. Discussion This study provides a detailed description of surgeons’ intraoperative leadership during different types of operative situations and stages. During the intraoperative period, the attending surgeon seemed to lead the surgical trainee almost exclusively, and not other members of the operative team. Leadership was highly focused on the surgical task.
Spatial Communication in Robotic Surgery
Authors: Cunningham Stacey , Cao Caroline G.L.
Published: October 2012

Surgical robots assist with precision tasks in minimally invasive procedures. The surgeon controls the robot from a console away from the operating table, reducing the opportunity for face-to-face communication in an otherwise team-oriented environment. This study examined spatial communication in a collaborative surgical task. It was hypothesized that spatial communication aids would improve performance in the task despite subjects’ innate spatial ability. Fifteen novice dyads completed a simulated organ manipulation task using a laparoscopic trainer box with a rotated (90o) camera view. Subjects were divided into 3 experimental groups: no aid, cardinal directions aid, and grid aid. A spatial ability test was also administered. Significant correlations were found between spatial ability, time, and communication volume in the no aid condition, an effect less apparent in the cardinal directions or grid aid conditions. These results suggest the benefit of a spatial communication aid to promote collaboration in robotic surgery.
Assessing Patient and Doctor Eye Gaze Patterns Between Two Styles of Doctor Ehr Use in Primary Care Encounters
Authors: Asan Onur , Montague Enid N. H. , Xu Jie
Published: October 2012

The purpose of this study is to understand the potential relationship between the ways primary care doctors interact with electronic health records (EHRs) and the eye gaze patterns of doctors and patients during primary care visits. Forty primary care encounters where doctors used two different EHR interaction styles were analyzed. This study used a lag analysis method to analyze the eye-gaze patterns between doctor and patient for each style. Differences and similarities in eye gaze behavior patterns were found between the two styles. The results of this study may inform guidelines for EHR design and implementation and inform EHR interaction training.
The Impact of Communication Training in High Fidelity Simulation of Emergency ICU Resuscitation
Authors: Breton Esther , Kramer Chelsea , Chamberland Cindy , Dubé Geneviève , Chiniara Gilles , Tremblay Sébastien
Published: October 2012

The intensive care unit (ICU) is a high-risk environment that requires cross-professional teams to provide life-saving patient care. There is ample evidence that poor communication creates situations where medical errors are likely to occur and affect patient safety. We tested whether communication-oriented debriefing following high-fidelity simulation improves quality of information exchange reflecting collaborative work in ICU teams. Ten teams of six cross-professional ICU workers participated in three simulation-based training sessions. After each training session, the experimental group was debriefed on communication-oriented skills (based on Crew Resource Management, CRM), while the control group was debriefed on technical skills. The analysis was double-blind; 30 videotaped sessions were coded for three types of communication measures by four observers showing adequate inter-rater reliability. Results suggest that high-fidelity simulation training can improve non-technical skills in cross-professional ICU teams. Further investigation is needed on the performance effects of communication-focused debriefing.
Adaptation of a Human Resource Model by the Use of Machine Learning Methods as Part of a Military Helicopter Pilot Associate System
Authors: Maiwald Felix , Schulte Axel
Published: October 2012

This article describes an approach how to improve a knowledge-based pilots’ associate system in the domain of military helicopter missions by the use of machine learning methods. To prevent the pilot from being overtaxed the associate system estimates the pilots’ residual mental capacity and thereby the current subjective workload . This estimation enables the associate system to selectively direct automation induced dialogues, e.g. hints, warnings, alerts, suggestions to the perceptual modality, which can be assumed to provide spare resources. Therefore, we developed task related models of mental resource demands for the military helicopter flying domain. To eliminate subjective influences from these models as far as possible, laboratory experiments have been conducted to better match the predicted resource conflicts within distinct task situations with the objectively measured pilots’ performance. Based on these experiments, we applied machine learning methods (i.e. genetic algorithms) to adapt the underlying human resource model to the measured human performance. By using suchlike models the associate system is enabled to cooperate with the pilot by resource adaptive information exchange. This article focuses on a specific aspect of the overall associate system related trials. We provide a detailed description of the conducted experiments used for adaptation of the resource model and the application of the machine learning technique for the model optimization as well as detailed results of the overall evaluation of thee associate system’s adaptive capabilities in a relevant mission context obtained in simulator experiments.
Tools for Predicting the Duration and Variability of Skilled
Authors: John Bonnie E. , Patton Evan W. , Gray Wayne D. , Morrison Donald F.
Published: October 2012

Many devices are designed to allow skilled users to complete routine tasks quickly, often within a specified amount of time. Predictive human performance modeling has long been able to predict the mean time to accomplish a task, making it possible to compare device designs before building them. However, estimates of the variability of performance are also important, especially in real-time, safety-critical tasks. Until recently, the human factors community lacked tools to predict the variability of skilled performance. In this paper, we describe a combination of theory-based tools (CogTool and SANLab) that address this critical gap and that can easily be used by human factors practitioners or system designers. We describe these tools, their integration, and provide a concrete example of their use in the context of entering the landing speed into the Boeing 777 Flight Management Computer (FMC) using the Control and Display Unit (CDU).
Fitts’ Law in 3D Space with Coordinated Hand Movements
Authors: Zeng Xiaolu , Hedge Alan , Guimbretiere Francois
Published: October 2012

The study tested the applicability of Fitts’ law to coordinated hand movements in a 3D response space with. An experiment was conducted in which 20 participants performed the Fitts’ pointing tasks with varying target distances, target sizes and approaching angles from a home position. Results confirmed that Fitts’ law applies to coordinated hand movements in 3D space.
A Discrete Movement Model for Cursor Tracking Validated in the Context of a Dual-Task Experiment
Authors: Zhang Yunfeng , Hornof Anthony J.
Published: October 2012

Understanding human cursor tracking behavior is essential in understanding human motor control. Though tracking has been hypothesized as a sequence of discrete movements, better data is needed to support the theory. By analyzing moment-to-moment tracking data, this paper shows that discrete, non-ballistic movements exist throughout a tracking task, and that these short submovements can be characterized by either Fitts’ law or a linear model. A cognitive model was built to incorporate the characteristics of these discrete movements into a dual task. Using parameters estimated through linear regression of the movement data, the model achieves a good fit to the overall performance measures of the dual-task experiment. This research investigates the characteristics of human motor control in tracking tasks, improves modeling techniques by providing a new method for estimating tracking parameters, and advances the science of motor control with new evidence for the discrete movement tracking hypothesis. The discrete movement model presented here offers an excellent alternative to established control theory models that are used to simulate steering in cognitive models of driving.
Towards Bridging the Gap between Biomechanics and Motor Control for Virtual Ergonomics Applications
Authors: Kajaks Tara , Lyons James L.
Published: October 2012

Posture prediction algorithms, particularly those that consider comfort (or discomfort), are typically based on gross movements rather than on the finer movements of the upper extremity. However, understanding these finer movements, particularly during goal-directed reaching tasks, is critical to accurately predicting postures, and the associated potential injury risks, when using virtual ergonomic tools. Furthermore, it is expected that these finer movements will be highly sensitive to the planning processes used to perform sequential tasks, particularly when start and terminal orientation, terminal precision, and terminal force are manipulated. Thus, the purpose of this proposed study is to challenge the theory of the end-state comfort effect under conditions of varying terminal precision and exertion force requirements during both discrete and sequential goal-directed reaching tasks. It is expected that each of these manipulations (i.e. start and terminal orientation, terminal precision, terminal force, and number of movement sequences) will influence the chosen movement patterns. Understanding how each of these variables affects movement patterns will provide important information for the development of posture prediction algorithms for use with virtual ergonomics tools.
Time Pressure, Memory, and Task Knowledge Facilitate the Opportunism Heuristic in Dynamic Tasks
Authors: Gartenberg Daniel , Breslow Leonard A. , McCurry J. Malcolm , Trafton J. Gregory
Published: October 2012

There are a variety of strategies that operators can utilize when performing a dynamic task, yet operator strategies are typically studied in a well-controlled environment that prevents the possibility of these strategies from interacting or competing with one another. In this study we investigated operator strategy use in a dynamic supervisory control task. We identified four possible strategies that the operator may use: scanning, opportunism, task knowledge, and memory. In order to determine the impact of time pressure on strategy use, we manipulated the speed of the vehicles. We found that as time pressure increased, operators shifted from a scanning strategy to a heuristic opportunistic strategy. We also found that when operators used task knowledge and memory they were more likely to be opportunistic.
Application of System Dynamics Modeling for the Assessment of Training Performance Effectiveness
Authors: Jiang Hong , Karwowski Waldemar , Ahram Tareq
Published: October 2012

System Dynamics Modeling (SDM) is a mathematical technique to understand the behavior of complex systems over time. SDM has been widely used and applied in modeling complex systems such as human performance and social network analysis. This paper highlights key features of the system dynamics approach for human performance modeling and training optimization. Using three of the Big Five factors which include Conscientiousness, Extroversion, and Openness, modeling results show how these factors interact and influence training performance. This research sum arizes the development of a system dynamics model for use in evaluating training performance, acquired personality traits and overall system effects on training proficiency.
Evaluating the usability of CAPTCHAs on a mobile device with voice and touch input
Authors: Wismer Andrew J. , Madathil Kapil Chalil , Koikkara Reshmi , Juang Kevin A. , Greenstein Joel S.
Published: October 2012

The usability of text-based CAPTCHAs, featuring distorted letters, and image-based CAPTCHAs, featuring pictures, was explored on an Apple iPad. Five conditions were explored: Confident CAPTCHA with either voice or touch input, ESP-PIX with voice or touch input, and Google’s CAPTCHA with touch input. Usability was analyzed in terms of performance, perceived usability, workload, and preference rankings. Results showed that CAPTCHAs involving touch input scored better in almost every measure than CAPTCHAs involving voice input. In particular, Confident Touch is recommended based on preference and perceived performance, whereas ESP-PIX Touch is recommended for its short completion time. When image-based CAPTCHAs are not feasible, Google’s CAPTCHA is a satisfactory alternative based on usability ratings.
Precise Positioning on Computer Monitors: Comparison of Mouse and Scroll Wheel in One Dimension
Authors: Pastel Robert
Published: October 2012

Precisely positioning graphical objects is an essential task for graphic designers. This paper compares precise positioning using a physically discrete device, indented scroll wheels, with positioning using a continuous device, standard mouse movements. The device (scroll wheel or mouse), positioned object height, positioning tolerance and initial object-target separation are varied while observing the error frequency, movement times and time to confirm that the object is accurately positioned. Positioning tolerance was varied from a single permissible position to 7 possible positions. Error frequency and confirmation time were less using the scroll wheel, while movement times were less using the mouse. Appropriate measures for the difficulty of precise positioning are discussed.
Assessing Posture While Typing on Portable Computing Devices in Traditional Work Environments and at Home
Authors: Werth Abigail J. , Babski-Reeves Kari
Published: October 2012

Mobile computers are becoming increasingly popular for many user populations, since they allow owners to perform computing activities in a number of settings (e.g., home, office). However, little research exists that quantifies ergonomic exposures associated with using mobile computing devices, particularly in non-traditional environments or for newer, compact mobile computers (e.g., slate computers). Therefore, the objective of this study was to quantify posture differences between mobile computing devices when performing data entry tasks at a traditional workstation and on a sofa. Wrist and neck flexion/extension (FE) and wrist radial/ulnar deviation (RU) were measured using electrogoniometers. When working at the non-traditional work station (i.e., sofa), postures were found to be degraded particularly when typing on the slate computer. These findings indicate that the potential or injury or illness may be elevated when working on smaller computers in non-traditional work settings.
The Effects of Autonomy and Cognitive Abilities on Workload and Supervisory Control of Unmanned Systems
Authors: Sellers Brittany C. , Fincannon Thomas , Jentsch Florian
Published: October 2012

In this paper, we examine the influence of autonomy and cognitive ability on workload in unmanned systems. First, we outline prior research regarding the role of autonomy and operator selection in decreasing workload in the realm of human-robot interaction. Next, we discuss two aspects of cognitive ability (i.e., visualization and perceptual speed) explain differences between these constructs, and their influence on workload. Then, we describe the current study and discuss the effects of varying levels of autonomy, visualization, and perceptual speed on workload in a simulated reconnaissance mission. Finally, we explore the implications of our findings in terms of the influence of autonomy and operator selection and provide suggestions for future research.
Effects of Input Modality and Expertise on Workload and Video Game Performance
Authors: Kent Travis M. , Marraffino Matthew D. , Najle Maxine B. , Sinatra Anne M. , Sims Valerie K.
Published: October 2012

A recent trend in consumer and military electronics has been to allow operators the option to control the system via novel control methods. The most prevalent and available form of these methods is that of vocal control. Vocal control allows for the control of a system by speaking commands rather than manually inputting them. This has implications not only for increased productivity, but also for optimizing safety as well as for assisting the disabled population. Past research has examined the potential costs and benefits to this novel control scheme with varying results. The purpose of this study was to further examine the relationship between modality of input, operator workload, and expertise. The results obtained indicated that vocal control may not be ideal in all situations as a method of input, as participants experienced significantly higher amounts of workload than those in the manual condition. Additionally, expertise may be more specific than previously thought, as participants in the vocal condition performed nearly identical at the task regardless of gaming expertise. The implications of the findings for this study suggest that vocal control be further examined as an effective method of user input, especially with regards to expertise and training effects.
Guiding Principles for Team Stress Measurement
Authors: Dietz Aaron S. , Sierra Mary Jane , Smith-Jentsch Kimberly , Salas Eduardo
Published: October 2012

Teams, like individuals, experience stress. While a number of theoretical models and empirical studies have examined the role and effects of stress on team processes and performance, there is surprisingly no guidance for measuring and diagnosing team-level stress. This paper proposes that team stress is a unique construct and necessitates robust measurement systems for its evaluation. To this end, the present paper presents four principles that serve to guide the development of valid and reliable team stress measurement systems.
Portraying the Contribution of Individual Behaviors to Team Cohesion and Performance
Authors: Parke Bonny , Orasanu Judith
Published: October 2012

Behaviors of individuals in teams both contribute to and are molded by team dynamics. How they do so has been the subject of much research. A method of portraying individuals’ behaviors in teams, the Team Diagramming Method (TDM) is presented. Behaviors are rated by other team members on three important dimensions: positivity/negativity, dominant/submissive, and task-orientedness/expressiveness. A study of 5-person teams engaging in a 3-day moon simulation task demonstrated that measures of these perceived behaviors as well as the variances of these behaviors correlated with cohesion measures and performance. The method shows strengths and weaknesses of particular teams and, by comparison with high-performing teams, suggests interventions based on individual as well as team behaviors.
Individual Differences in Cognitive Flexibility Predict Performance in Vigilance Tasks
Authors: Figueroa Ivonne J. , Youmans Robert J.
Published: October 2012

‘Real-world’ vigilance tasks are difficult to perform because they require sustained and divided attention. The present study investigated whether individual differences in a person’s cognitive flexibility, the ability to abandon one cognitive strategy in favor of another, can predict performance on a vigilance task. Sixty-one undergraduate students from California State University, Northridge participated in this study. The Wisconsin Card Sorting Task was used to measure participants’ level of cognitive flexibility. Vigilance was examined using a multi-screened Clock Task. Participants then performed either a nine-minute Static or Dynamic Clock task. Two variables of cognitive flexibility were found to predict signal detection. Cognitive flexibility may eventually become a useful individual difference measure that can help provide insight for vigilance training strategies.
Observed postural variations across computer workers during a day of sedentary computer work
Authors: Black Nancy , DesRoches Leon , Arsenault Isabelle
Published: October 2012

Sedentary computer work is widespread and typically occurs at a fixed-height seated workstation. Both neutral and at-risk postural classes of the back and neck were observed among 11computer-intensive workers using such workstations who had reported high discomfort levels. Four video recordings of approximately 1 hour each over the working day were analyzed to determine the percent duration and number of observations of each body and neck posture. Risky slouching (32.3% ±17.3%) and neck forward postures (16.9% ±12.3%) varied significantly by participant but not by time of day. Absence from video field of view of the workstation was not negligible, occurring 23.8%±14.8%. Postural changes of slouch and neck forward occurred several times during each recording (4.8±1.9 and 2.5±0.9, respectively) and varied significantly by participant but not over the day. Despite these postural adjustments, the prevalence of risky postures suggests that static workstations are fundamentally problematic.
Spectral Analysis of Root-Mean-Square Processed Surface Electromyography Data as a Measure of Repetitive Muscular Exertion
Authors: Gant Lauren , Fethke Nathan , Gerr Fred
Published: October 2012

Highly repetitive motion is associated with development of upper extremity musculoskeletal disorders (UEMSDs) among industrial workers, especially when encountered concurrently with forceful exertions. Current measures of “repetitiveness” provide information about the repetitiveness of joint motion, but fail to provide complete information about the repetitiveness of muscular exertion, a more biomechanically meaningful measure of repetition. The current study introduces a novel processing technique in which surface electromyography (sEMG) data is root-mean-square processed prior to computation of the frequency spectrum. The mean power frequency of the resulting power spectrum is the proposed metric for estimation of muscular exertion frequency. The metric was compared to joint movement and applied force frequencies during a series of isometric gripping trials and an industrial simulation. Results suggest that the proposed metric has potential to be a valuable metric to estimate exposure to repetitive muscular exertion.
Serum and MRI Biomarkers in Mobile Device Texting: A Pilot Study
Authors: Gold Judith E. , Mohamed Feroze B. , Ali Sayed , Barbe Mary F.
Published: October 2012

Text messaging has become widespread, particularly among college-aged young adults.

There is concern that high rates of texting may result in musculoskeletal disorders, including tendinopathies. We examined serum biomarkers, conventional MRI findings, and MRI mean intratendinous signal-to-noise ratio (MISI) of thumb tendons to determine if high volume texters (≥ 230 texts sent/day; n = 5) would be more likely than low volume texters (≤ 25 texts sent/day; n = 5) to have early onset tendinopathy and inflammation. Three of the high volume texters had MRI findings of tendinopathy as did one low volume texter. Increased serum TNF-R1 was found in high volume texters compared to low volume texters of college age, as were non-significant increases in MISI in 2 thumb tendons. Serum TNF-R1 and TNF-α correlated with the MISI in these tendons, as did IL1-R1. These results suggest that early onset tendinopathy with concurrent inflammation may be occurring in prolific texters. Further studies with larger sample sizes are needed to confirm these findings.
Licensed Massage Therapist Strain Index Scores
Authors: Page Lenore T.
Published: October 2012

Massage Therapists (MT) are almost exclusively self-employed and lose income if they are unable to perform massage treatments. This study investigated MT workplace pain via survey and assessed musculoskeletal disorder (MSD) risk by video recording MT massage treatments then calculating the Strain Index (SI) scores. First, randomly contacted MTs (16 respondents of 100 cold calls) completed an online survey about their work practices. Despite 87% of MTs reporting self care regimes, 83% reported work-related pain in the wrist or thumb over their careers with 57% experiencing pain in the last 30 days. SI scores were calculated for a 60 minute, naturalistic massage performed by seven licensed MTs (six female and one male reflecting the MT population sex proportions). There was suggestive evidence that the average and maximum hands-on day mean peak right hand SI scores ( M = 5.6 and 7.7, SD = 4.30 and 5.73, and p = 0.08 and 0.04, respectively) were greater than an SI of 3.0 (moderate risk for MSD). There was no evidence of MSD risk for the left hand ( M = 3.2 and 4.3, SD = 2.93 and 3.91, and p = 0.42 and 0.20, respectively). MTs may be at moderate risk of incurring work-related upper extremity disorders.
B Factor and its Importance to HFE Practitioners - Applying NIOSH’s 1991 Revised Lifting Equation and its Derivatives
Authors: Borchardt James G. , Choi Sang D.
Published: October 2012

Weight of materials is an essential component of National Institute of Occupational Safety and Health’s (NIOSH) 1991 Revised Lifting Equations, its European (BS EN)/International (ISO) derivatives and other published extensions/modifications. Weighing materials is often difficult at construction work sites. NIOSH’s Lifting Equation and its variations might be used more frequently and effectively by Human Factors/Ergonomic (HFE) Practitioners if the weight of materials could be determined more easily at work sites. The Borchardt Factor (B Factor) concept would enable HFE Practitioners to “calculate” the weight of large, bulky or irregularly shaped materials at work sites. The B Factor is defined as: Weight (lbs or kg) per “easy to measure” unit of measurement.
Low Back Muscle Fatigue Measurements of Cyclic and Prolonged Stooped Work
Authors: Nou Danny , Miller Brandon J. , Fathallah Fadi A.
Published: October 2012

Fatigue experiments were performed on human subjects to study muscle fatigue measurements of the erector spinae muscles during cyclic and prolonged static stooped bending using electromyography (EMG). Nineteen subjects participated in the study. The median muscle firing frequency ( fm) data of the erector spinae muscles were measured noninvasively and continuously during simulated cyclic and prolonged stooped work. In the prolonged condition, the subject conducted an isometric stooped work at 4:1 work to rest ratio; whereas in the cyclic condition, the subject conducted an isometric stooped work at 4:1 work-to-rest ratio; each followed by a recovery period. To quantify the rate of fatigue, a fatigue index was defined as the change in the fm with respect to muscle activation time. All measurements were normalized to each subject’s individual erector spinae maximum voluntary contraction using the Biering-Sørenson Muscle Endurance test for lower back endurance as control measurement. The results indicated that the use of EMG showed no significant differences in the muscle fatigue between cyclic and prolonged stooped conditions. However, when EMG results for both are compared to the control conditions, similar fatigue responses are shown. This may be an indication that both cyclic and prolonged stooped work conditions are equally detrimental to the spine, which calls for effective interventions to limit their effects on workers who commonly perform these types of tasks.
Investigating the effects of slipping on lumbar muscle activity, kinematics, and kinetics
Authors: Rashedi Ehsan , Jia Bochen , Nussbaum Maury A. , Lockhart Thurmon E.
Published: October 2012

Slips, trips, and falls remain leading causes of occupational injuries and fatalities. The current exploratory study quantified lumbar kinematics and kinetics during both induced slips and normal walking. Individual anthropometry, lumbar muscle geometry, and lumbar kinematics, along with electromyography of 14 lumbar muscles were used as input to a 3D, dynamic, EMG-based model of the lumbar spine. Results indicated that, in comparison with values during normal walking, lumbar kinematics, lumbosacral kinetics, lumbar muscle activations, and lumbosacral reaction forces were all substantially increased during a slip event. Observed levels of muscle activity and lumbosacral reaction forces suggest the potential for low back injury during a slip event. Outcomes of this work may facilitate the identification and control of specific mechanisms involved with low back disorders consequent to a slip.
Using Multiple Complementary Methods to Develop Ergonomics Audits for Mining Operations
Authors: Dempsey Patrick G. , Porter William L. , Pollard Jonisha P. , Drury Colin G.
Published: October 2012

Although ergonomics audits are commonly used by consultants, the scientific literature on reliable and valid audits is sparse. This paper describes a multi-faceted methodological approach to developing ergonomics audits for three types of mining operations. The approach was derived from a validated audit (Ergonomics Assessment Program (ERNAP)) for aircraft maintenance operations. While there were contextual, regulatory, and intended end user differences, the general approach to establishing content validity through task analysis and workplace observations, surveillance data, and accepted practices and regulations proved to be effective, albeit with modifications. Analysis of fatality reports and desire for integration with existing mining safety approaches were two areas where the current approach differed from ERNAP.
Evaluation of an FAA Maintenance Agency Using an Organization Development Approach
Authors: Pierce Linda , Byrne Cristina , Williams Clara
Published: October 2012

An action research approach was used to plan for organization development (OD) in centers within the Federal Aviation Administration (FAA) responsible for remote monitoring and coordination of maintenance. Research participants worked in one of three centers. The participants were asked questions about their technical background; interdependencies, structure, complexity, and workload inherent in the job; cohesion and trust among co-workers; and perceived operational effectiveness and job satisfaction. Results were summarized and categorized as related to workload, resources, and knowledge of results. Strategies to address one or more of the factors identified were proposed. Strategies included the use of small teams to organize work, a revised training approach for new employees and leaders, internal and external mechanisms for performance feedback, and a fatigue risk management approach to improve shift work practices. The next step will be to work with managers to tailor and implement selected strategies.
The Effect of Keyboard Key Spacing on Productivity, Usability, and Biomechanics in Touch Typists with Large Hands
Authors: Pereira Anna , Lee David L. , Sadeeshkumar Harini , Laroche Charles , Odell Dan , Rempel David
Published: October 2012

International standards that specify the spacing between keys on a keyboard have been guided primarily by design convention. Experienced typists (N=37) with large hands typed on five keyboards with different horizontal and vertical key spacing (19x19, 18x19, 17x19, 16x19, and 17x17mm) while productivity, comfort ratings, left and right extensor carpi ulnaris (ECU) and flexor carpi ulnaris (FCU) muscle forces, and right and left wrist extension and ulnar deviation were recorded. Productivity and usability ratings were significantly worse for the 16x19 keyboard. There was a trend for muscle activity to increase in the left forearm and decrease in the right forearm with decreasing horizontal key spacing. There was also a trend for left wrist extension to increase and left ulnar deviation to decrease with decreasing horizontal key spacing. The study findings support key spacing on a keyboard between 17 and 19mm. These findings may influence keyboard standards and design of keyboards.
Thumb Motor Performance is Greater for Two-Handed Grip Compared to Single-Handed Grip on a Mobile Phone
Authors: Trudeau Matthieu B. , Young Justin G. , Jindrich Devin L. , Dennerlein Jack T.
Published: October 2012

The aim of this study was to determine if thumb motor performance varied between singlehanded and two-handed grip for thumb tapping tasks on a mobile phone. A secondary aim was to determine if differences in phone movement variation and thumb flexion could account for variations in motor performance across the two grip configurations. Ten right-handed participants (5 males, 5 females) completed reciprocal thumb tapping tasks on an Apple iPhone 3® in a single-handed and a two-handed grip configuration while an active-marker motion capture system measured 3D kinematics of the thumb and phone. The results show that thumb motor performance was significantly greater for the two-handed grip configuration due to less phone movement variation compared to the single-handed grip configuration. Thumb flexion did not significantly vary across configurations. These data suggest that increasing support for the phone such as by using a two-handed grip could lead to increases in tapping performance. For example, increased performance would be expected when using phones that include a landscape mode and are wide enough to allow a stable two-handed grip.
Ergonomic Design of a Main Control Room of Radioactive Waste Facility Using Digital Human Simulation
Authors: Lee Baekhee , Chang Yoon , Jung Kihyo , Jung Ilho , You Heecheon
Published: October 2012

The present study evaluated a preliminary main control room (MCR) design of radioactive waste facility using the JACK® digital human simulation system. Four digital humanoids (5th, 50th, 95th, and 99th percentiles) were used in the ergonomic evaluation. The first three were selected to represent 90% of the target population (Korean males aged 20 to 50 years) and the last to reflect the secular trend of stature for next 20 years in South Korea. The preliminary MCR design was assessed by checking its compliance to ergonomic guidelines specified in NUREG-0700 and conducting an in-depth ergonomic analysis with a digital prototype of the MCR design and the digital humanoids in terms of postural comfort, reachability, visibility, and clearance. For identified design problems, proper design changes and their validities were examined using the JACK. A revised MCR design suggested in the present study would contribute to effective and safe operations of the MCR as well as operators’ health in the workplace.
Preliminary research to decrease splashing mud during walking
Authors: Kaminishizono Takeyoshi , Sakai Sakiko
Published: October 2012

Splashing mud caused by walking on wet surfaces is one of the annoying aspects of daily life. Previous research has shown that the degree to which mud splashes is highly dependent on walking posture. However, proper shoe design can help to minimize this problem. Preliminary research is required to enable the designing of shoes that will miinimize splashing mud. This study demonstrated how shoe fit contributes to the splashing of mud when walking on wet, muddy surfaces. In the experiment, subjects showed a varying number of mud splashes after walking on a simple artificial wet path wearing shoes that fit differently. The results demonstrated a strong association between shoe fit and the number of mud splashes in all subjects. The results of this research suggest that a proper shoe design can decrease the splashing of mud when walking on wet, muddy surfaces.
Analysis of the Facial Anthropometric Data of Korean Pilots for Oxygen Mask Design
Authors: Lee Wonsup , Park Jangwoon , Jeong Jeongrim , Jeon Eunjin , Kim Hee-Eun , Park Seikwon , You Heecheon
Published: October 2012

The present study measured Korean pilots’ facial dimensions to design a pilot oxygen mask which would fit Korean pilots, and compared Korean pilots’ facial dimensions to Korean male civilians and US male pilots’ facial characteristics. The present study selected the 22 facial anthropometric dimensions related to oxygen mask design by referring to previous studies. The facial dimensions of 366 Korean male and female pilots (including 52 female cadets of the Korean Air Force Academy) were measured using Martin’s anthropometer and 3D scanner. Korean male pilots’ faces were significantly larger (mean difference = 1.3 ~ 27.0 mm) and less variable (ratio in SD = 0.29 ~ 0.85) than Korean male civilians’ faces ( α = 0.05), which indicates that facial anthropometric data derived from Korean pilots should be used to design the oxygen mask for Korean pilots. In terms of criteria of the oxygen mask sizing system which is currently based upon the US Air Force anthropometric data (face length and lip width), Korean male pilots were significantly longer on face length (mean difference = 4.7 mm) and narrower on lip width (mean difference = -2.4 mm) than US male pilots ( α = 0.05), which indicates that the oxygen mask sizing system as well as the oxygen mask shape should be changed for Korean pilots. Additionally, Korean male pilots have wider nasal roots (mean difference = 5.2 mm) than US male pilots, which indicates that the shape of nose of the current oxygen mask should be widened. Lastly, Korean female pilots’ facial dimensions were significantly smaller (mean difference = 0.6 ~ 26.1 mm) than Korean male pilots ( α = 0.05), which indicates that Korean female pilots’ facial characteristics need to be considered in the design of oxygen masks which fit Korean pilots.