bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dimensions and Degrees of Adaptation: A Synergistic Analysis
Authors: Carter James A.
Published: January 2012

System adaptation is necessary as organizations and individuals evolve. There are various ways in which systems can be made to adapt. By identifying the dimensions and degrees of adaptation and selecting those feasible to implement, it is possible to incorporate useful adaptive features in the systems of today.
The Role of Human Factors Guidelines in Designing Usable Systems: A Case Study of Operating Room Equipment
Authors: Potter Scott S. , Cook Richard I. , Woods David D. , McDonald John S.
Published: January 2012

Recently, the Association for the Advancement of Medical Instrumentation (AAMI) adopted human engineering guidelines which represent the first formal compilation of general human factors materials for use by medical equipment designers. The applicability of these guidelines was addressed by evaluating a new microprocessor based device based on the AAMI guidelines and again using broader principles and techniques from human-computer interaction (HCI). While the device met the majority of applicable guideline recommendations, the second review identified more substantive human engineering deficiencies not addressed by the AAMI recommendations. Examples included hidden modes of operation, inconsistent signal-action mapping, complex resetting sequences, and violations of expectations. Application of these HCI issues predict confusion in using the device and limitations in diagnosing and correcting problems. Interviews with users of the device confirmed these predictions by finding that participants had major gaps, inconsistencies, and misconceptions in their mental models of the device. This investigation suggests that, in an era of microprocessor based devices, traditional human factors guidelines are only a starting point for a comprehensive approach to equipment design. To be effective as design aids (especially for designers not trained in human factors), human factors guidelines must address and incorporate HCI issues. Additionally, emphasis needs to be on methodologically oriented principles (Gould, 1988; Woods and Eastman, 1989) to aid designers in the process of design.
Navigating through Large Display Networks in Dynamic Control Applications
Authors: Woods David D. , Roth Emilie M. , Stubler William F. , Mumaw Randall J.
Published: January 2012

There is an increasing trend to use computer display systems as the primary “window” by which users see and interact with complex dynamic processes (e.g., air traffic control; computerized control rooms for process control). These kinds of applications offer special challenges to the design of computer based display systems. In particular, the large scope of these applications necessitates large display structures involving thousands of displays. Further, the dynamic nature of the tasks mean that users need to be able to move rapidly through the display structure to keep pace with temporally evolving situations and to be able to respond to new events as they occur. As a result, special display navigation challenges arise in computer based display systems for monitoring and controlling dynamic processes.
The Video Analysis Method: An Integrated Approach to Usability Assessment
Authors: Prasse Michael J.
Published: January 2012

The videotape record of a user-system interaction can be very valuable in locating usability problems. However, the analysis of the videotape record is often unstructured, non-quantitative, and time-consuming. The Video Analysis Method (VAM) provides a method to structure this data and derive measures of usability. A grammar integrates the videotape data with transaction log information and segments of the program code into a single representation of the interaction. Various usability metrics can then be derived from this representation. In addition, the use of the transaction log to edit usability problems from the videotape before the application of the grammar reduces the total analysis time.
Performing Speech Recognition Research with HyperCard
Authors: Shepherd Chip
Published: January 2012

In the Macintosh world of computing, HyperCard, an information management software package, has become a popular tool for developing rapid-prototypes of user interfaces. The development of the first Macintosh-based speech recognizer (by Articulate Systems, Inc.) has enabled engineers at the NASA Johnson Space Center (NASA-JSC) to use HyperCard to develop prototype speech recognition interfaces for space applications. Using specifications from NASA-JSC contractor engineers, special HyperCard XCMD's were developed by Articulate Systems to assist in NASA-JSC's research applications. By working with these programs, project engineers have learned how to use them to unobtrusively collect and record quantitative speech recognition data. The objective of this report is to describe the features of the system and to instruct HF professionals how to perform speech recognition research with HyperCard.
Designing Consumer Product Displays for the Disabled
Authors: Ward John T.
Published: January 2012

In this portion of an on-going effort to develop human factors guidelines for designing consumer products for the disabled a series of interviews and surveys concerning information displays was conducted in the homes of noninstitutionalized disabled people. The study covered a variety of disabilities, and where possible, individuals with several different levels of a given disability were included.

A detailed set of recommendations of specific displays for use on products to be used by disabled people proved impractical because interfaces which are found desirable by one disabled person are often a bad choice for another. It was found that good human factors design is especially appreciated by the disabled who, in general, are very smart consumers.

The most significant display usability problem for the sensory disabled subject is the mix of displays often found on top-of-the-line products. There is a ‘space-age/jet cockpit' look which seems to be popular in display design; it is not popular with the disabled. The current fad toward displaying information on a wide variety of alternating channels is likely to cause a display to be rejected by a disabled customer. In its original military/cockpit use this design approach serves the purpose of preventing the overload of any one human input channel. On household, or public access, interfaces where the intensity of information display is relatively low the use of alternating display channels often insures that a user not able to sense one of the output technologies is unable to use the device.
Strength of Component Principles Determining Direction-of-Turn Stereotypes for Horizontally Moving Displays
Authors: Hoffmann Errol R.
Published: January 2012

Direction of turn stereotypes were determined for horizontally moving displays with various knob locations, combined with top and bottom scales which either increased or decreased to the right and having neutral or directional indicators. Equations were written for the strength of the stereotype (proportion of clockwise movements) in terms of the direction predicted by various principles; clockwise to increase, clockwise to the right, clockwise away, scale-side and Warrick's. Solution of these equations for the case of knobs located at the sides of the display showed that the strength of the stereotype was largely determined by “clockwise to right” principle (about 51% and 93% respectively for groups of engineering and psychology students). The corresponding figures for the “scale-side” principle of Brebner and Sandow were 16% and 2%. Knobs located either on the top or bottom of the display have movement stereotypes determined by Warrick's principle (54% and 15% for engineering and psychology groups) and “clockwise to the right” (38% and 80%, respectively, for engineers and psychologists). The “scale-side” principle was found to be very weak (2%) in this case.
Strength of Component Principles for Direction-of-Turn Stereotypes of Three-Dimensional Display/Control Arrangements
Authors: Hoffmann Errol R.
Published: January 2012

It was shown by Hoffmann (1990) that the strength of component principles determining the stereotype for control rotation with linear displays could be readily determined in cases where the control was in the same plane as the display. The work was extended to the case of three-dimensional display/control relationships, where the rotary control is not in the same plane as the display. Two experiments are reported, one using paper and pencil tests and the other simulated diplays and controls. The strength of the component principles are determined for each of these. It was found that (i) the paper and pencil tests gave a good prediction of data obtained with the simulated displays in cases where Warrick's principle was applicable, except that the strength of several of the principles varied slightly from those with the hardware; (ii) strong stereotypes were found for cases in which Warrick's principle was applicable, but not in cases where the axis of the control was parallel to the direction of motion of the display; (iii) in all cases where Warrick's principle was applicable, the stereotypes were reversible, whereas in a number of the tests where Warrick's principle could not be applied this was not the case. As in the case of planar display/control arrangements, the component strengths of the various principles can be linearly added to obtain the strength of the stereotype for any given relationship between display and control. The approach gives a better understanding of the values found for stereotypes with different arrangements of displays and controls.
Design Evaluations of Radial Arm Saws
Authors: Abedini Kamran
Published: January 2012

Due to the recent do-it-yourself philosophy of marketing for general furniture and household items in addition to the actual financial savings associated with producing one's own items of need have increased the market for miniaturized production type equipment such as drill presses and radial arm saws. Thus far such equipment only existed in shops where they were only used by the professionals and the novice had only the least access to them. Due to the changes in the market, it has become evident that the design of such equipment should be monitored to ensure that all users are effectively considered in their design.

This paper reviews the design of small production type equipments with emphasis on a typical radial arm saw. The actual operation of the saw is presented and the design problems are noted. The critique was based on several widely used human factors design criteria. Further specific solutions are provided for a redesign of the equipment. A mock-up of a newly designed saw is then presented where improvements are incorporated. Finally, a set of design criteria are established in order to provide the manufacturer of such production equipment with guidelines on how to economically improve the design for the user of their products.

A videotape is produced in order to use human factors guidelines for evaluations of a radial arm saw. The tape also presents a 3 dimensional model of a redesigned saw. Acceptable humor was used throughout the production of the tape in order to increase the effectiveness of the presented material.
PRISMA: An Integrated Slide Management and Projection System HF and ID Collaboration in Design
Authors: Segal Leon D. , Bar-Or Jonathan
Published: January 2012

PRISMA is a new concept for the management and projection of 35mm. slides. The product is the result of a collaboration between two design-oriented disciplines — Human Factors and Industrial Design. The purpose of this paper is twofold. First we describe the product itself, focusing on the role of Human Factors knowledge and Industrial Design wherewithal in defining and shaping the final object. Second, we generalize from this one example, proposing a framework for the essential collaboration of Human Factors experts and Industrial Designers.
The Effect of Hazard and System Information on Estimated Risk
Authors: Moore Jana L.
Published: January 2012

Warning labels are used, in part, to increase risk estimates associated with hazardous equipment and products. Past research has demonstrated exposure to warning labels is related to risk estimates; however, it is not known whether warning labels cause an increase in risk estimates, as is generally assumed, or whether individuals who appreciate the danger of a situation are more likely to notice, read, and comply with warning labels. The purpose of this research was to determine the impact of two types of information on estimated risk: hazard and basic system (nonhazard) information. Research participants (77 males and 89 females) were divided into one of four information groups: 1) hazard, 2) system, 3) control, and 4) both hazard and system. As expected, hazard information, presented in a warning label, increased risk estimates. Contrary to hypothesis, system information alone did not appear to increase risk estimates. Finally, risk estimates were highest for participants who received both hazard and system information.
Critical Issues and Developments in Graduate Training and Continuing Education in Human Factors
Authors: Chambers Randall M.
Published: January 2012

Considering the variety and sources of graduate training and continuing educational programs which lead to the science and professional practice of human factors, this panel identifies and discusses important issues and developments in the training and education of human factors specialists. Then it recommends appropriate and professional solutions and approaches to these issues from the perspectives of universities and other institutions which are engaged in human factors training and education, research and application, and the professional practice and utilization of human factors. In the training and education of human factors specialists, there are important professional and scientific issues which may be examined as the human factors discipline progresses toward accreditation and certification, and new developments and accelerated growth continue to increase professional competence and social responsibility.
Improving Thermal Comfort in Offices: The Impact of Underfloor Task Ventilation
Authors: Hedge Alan , Michael Abigail T. , Parmelee Sharon L.
Published: January 2012

Questionnaire surveys measured the reactions of 6 facilities managers and 151 office workers to under-floor task ventilation. Facilities managers received fewer complaints about thermal discomfort and ventilation problems than in their previous buildings, and were very satisfied with task ventilation. A majority of office workers said that task ventilation improves thermal comfort, perceived air quality, and provides good temperature and ventilation conditions to support productive working and to help maintain alertness at work. Age and sex interactions were found for several environmental conditions, and women generally reported more frequent problems with thermal discomfort and ventilation.
Designing Habitats to Support Long-Duration Isolation and Confinement
Authors: Stuster Jack
Published: January 2012

This presentation summarizes research conducted to identify and evaluate the features of a designed environment that contribute to habitability. Habitability is defined and discussed in terms of 13 dimensions relevant to conditions in which human crew live and work in isolation and confinement. Design suggestions are presented to enhance human performance and productivity, and a research program is described that has led to significant habitability improvements in isolated and confined military environments.
Tire-Rim Mismatch Explosions: Human Factors Analyses of Case Studies Data
Authors: Laughery Kenneth R. , Mayer David L. , Vaubel Kent P.
Published: January 2012

Data from 13 accidents involving mismatches of 16 inch tires and 16.5 inch rims were analyzed. These mismatches resulted in tire bead failures during inflation that caused the assembly to explode leading to serious injuries and deaths. The data indicated a number of consistent findings. In ten of the accidents an “entrapment” situation existed in which the person inflating the tire and subsequently injured was not the person who selected the components and placed the tire on the rim. While there was great variance in training, experience and knowledge of tire busters, virtually all were unaware of this mismatch hazard. Tire busters typically did not look for size information on rims, and such information was either not displayed or displayed poorly. Regarding task feedback, because the outer flange diameter of the 16 inch and 16.5 inch rims are virtually the same, placing the tire on the 16.5 inch rim did not provide feedback that something was wrong due to greater task difficulty. Also, the fact that the tire did not properly seat was not attributed to a size mismatch but rather to other more common seating problems. Efforts to warn about the mismatch hazard on the products have not met warnings design criteria and generally have not been effective.
Perceptual Factors in Rear-End Crashes
Authors: Mortimer Rudolf G.
Published: January 2012

Some statistics of rear-end crashes are given and their characteristics are described. The perceptual factors related to discerning closure, headway change and visual angle change and rate of change of visual angle, are described by prior research and analysis, and threshold values for them are given.
Comparison of the Effects of Two Antihistamines on Cognitive Performance, Mood, and Perceived Performance
Authors: Rice Valerie J. Berg
Published: January 2012

This study compared the effects of three treatments (two antihistamines and one placebo) on cognitive information processing, mood, subjective feelings of drowsiness, and subjective performance ratings in 28 healthy men. Evaluations were given at 1, 3, 5, 7, 9, 11, 13, and 15 hours post ingestion. Results revealed performance decrements post diphenhydramine (benadryl) ingestion on three tasks. No decrements in performance were found post ingestion of hismanal. Subjective effects of mood were noted for both antihistamines; however, these effects were greater post benadryl. Subjects were able to determine receipt of a placebo versus an antihistamine following ingestion of either a placebo or benadryl. Results suggest that hismanal is superior to benadryl for avoidance of subjective effects and performance of information processing tasks.
Coordination of Kinematic Events during Simple Arm Movements
Authors: Woldstad Jeffrey C.
Published: January 2012

This paper examines the pattern of kinematic events underlying repeated performance of simple rapid elbow flexion movements to a fixed target. The limb positions and time samples of kinematic indices are derived from forearm movement trajectories and measurements of the forces tangent to the arch described by the forearm during motion. The pattern of kinematic events are compared for different levels of the inertial load moved, distance traveled and target width. Results demonstrate that both time samples and limb positions corresponding to peak acceleration, peak velocity and peak deceleration varied significantly with inertial load and movement distance, but were relatively unaffected by changes in target width. Changes in the timing of kinematic events demonstrated no clear pattern across manipulations. Forearm positions, however, were highly proportional to the movement distance, with peak acceleration approximately 7% of the distance to the target, and peak velocity and deceleration approximately 47% and 87% of the distance to the target, respectively. These results are interpreted as indicating that the control processes governing the construction of motor commands are organized in terms of limb position instead of more traditional force-time representations. Mechanisms of this type are consistent with recent mass-spring models of muscle control.
In-Car Road Information: Comparisons of Auditory and Visual Presentations
Authors: Labiale G.
Published: January 2012

Two studies investigate the effects of presentation modalities (visual/auditory/repeated auditory) and complexity levels of different in- car road information on subjective preferences and on perceptual and cognitive performances of drivers. In real driving situations, each driver was alerted by a ringing signal prior to the presentation of a road information message or a map display associated with a road guidance message; the experimenter asked each driver 30 s. later to recall the message or the itinerary. Results suggest that in real driving situations, short auditory road information messages or associated with map displays optimize perceptual and cognitive performances and driving safety; written messages are of greater interest if screened when the vehicle is at rest.
Wheelchair Lifts in Public Transportation
Authors: Breaux James W. , Chen Jen-Gwo
Published: January 2012

This paper provides an overview of a simulation project undertaken to provide data concerning the addition of wheelchair lifts to public buses on routes in the metropolitan Houston area. One bus route without lifts is researched and a computer model is constructed and validated to behave in a manner comparable to the real system. The validated model is then modified to add wheelchair lifts and experiments are performed to determine the schedule and incidental effects of the lift addition. The experiments consist of varying the percent of population expected to demand the lift and special seating areas on the modified buses. In general the effect of adding the lift to this single bus model is to sharply lower the probability that the bus will be early at scheduled stops and to increase the probability that the bus will be late at the scheduled stops. These probabilities vary in response to lift demanding population changes. Data for the lift-requiring passengers that will be unable to board on demand due to the limited capacity of the buses for wheel-borne passengers are also gathered from the model.
Low Cost, Real Time Simulation Based on Microcomputers
Authors: Allen R. Wade , Hogue Jeffrey R. , Stein Anthony C. , Aponso Bimal L. , Rosentha Theodore J.
Published: January 2012

This paper describes a general approach for implementing fixed base, person-in-the-loop, vehicle control simulations on IBM-PC compatible computers. The elements of fixed base (no motion) simulations are reviewed, including the vehicle math model, auditory and visual displays, and performance measurement. Two simulation examples are discussed, including a highway vehicle control task and a parachute maneuvering task.
Human Factors and Human Error
Authors: Malone Thomas B.
Published: January 2012

One human factors method for reducing human errors involves investigation of critical incidents to understand the dynamics and etiology of human error. This paper focuses on the use of the critical incident approach to understanding human error. Specifically, the paper describes human error scenarios that occurred at Three Mile Island (TMI), Chernobyl, Bhopal, KAL-007, and the VINCENNES incident. All of the critical incidents of human error described were caused, to some extent, by human complacency with technology, by erroneous expectancies concerning what was going on in the system and in the world, and by deficiencies in the design of equipment and the training of personnel. The major lesson learned from these critical incidents is that, to avoid such disasters, complex systems must be designed in terms of the capabilities, limitations and requirements of the personnel who operate, manage, maintain or otherwise use them. Systems personnel must be considered to be an important component of the system, to be designed into the system rather than added on after system design is complete. These accidents happened because system designers failed to take into account the needs and limitations of people in the systems. Application of human factors technology in the design of complex systems will significantly reduce the potential for similar incidents occurring in the future.
Comparing Geometric Object and Conventional Displays in Patient Monitoring
Authors: Deneault Lee G.
Published: January 2012

Anesthesiologists are highly trained professionals who are usually determined to maintain high standards while performing difficult tasks in life-threatening environments. Anesthesiologists must make a variety of decisions, in real-time, based on inputs from a myraid of monitoring instruments in much the same way as pilots of high performance air craft or nuclear power plant operators. Unfortunately the design of their displays is much poorer. This paper reports research aimed at extending the capabilities of the current monitoring system to integrative displays supporting the anesthesiologist's tasks of compensation and diagnosis.
The Effects of Chair-Type and Workstation Configuration on Work Performance
Authors: Rogers Christopher W. , Thomas Robert E.
Published: January 2012

The relationship between workstation design and the productivity of human operators is a topic of significant interest in contemporary ergonomics. Accordingly, this research consisted of two experiments which evaluated the effects of chair-type, work height and thigh-work surface angle on the upper extremity performance and comfort of females in two-hour sessions in a controlled work environment. The first experiment used six females as blocks in the statistical design and varied the chair-type between two types of “ergonomic” chairs and a wood chair. Non-significant trends indicate that light assembly production rose when using the ergonomic chairs an average of 7% in the final 30 minutes of each session. Overall comfort ratings significantly favored the ergonomic chairs. The second experiment used two females and varied three elbow heights and three thigh-work surface angles in nine combinations in a 32 factorial design. Nonsignificant trends indicated that assembly rates rose 5–7.8% when using a 185-degree or 155-degree angle in the final 30 minutes and 7.5–9% in the final 15 minutes. Both experiments revealed very few significant subject body part discomfort or chair feature differences between independent variables. Reaction times were negatively related to upper body part discomfort in both experiments. The research methodology proved valid and could be expanded in later studies.
Quantification of Back Motion during Manual Material Handling Tasks
Authors: Ferguson Sue
Published: January 2012

The objective of this project was to study the effects of asymmetric (twisting) free dynamic lifting on back motion characteristics in the sagittal, frontal and transverse planes of the body. Back motion charateristics were quantified both as a function of task asymmetry and task weight. An experiment with 21 subjects was performed in the laboratory, which simulated free dynamic manual material handling tasks of the industrial workplace. The results quantified the range of motion, peak velocity, average velocity, and peak acceleration in each plane necessary to complete the task. Plots were made of the statistically significant back motion parameters. The results quantified the amount of transverse plane back motion required for specific task asymmetries. Task asymmetries greater than 120 degrees require transverse motion that puts a person at high risk of suffering a low back injury. The results provide new insight into factors associated with the risk of developing low back disorders.
Ergonomic Evaluation of a Cabinet Manufacturing Facility
Authors: Nestor David E. , Bobick Thomas G. , Pizatella Timothy J.
Published: January 2012

A Health Hazard Evaluation was conducted by researchers from the National Institute for Occupational Safety and Health, Division of Safety Research at a cabinet manufacturing facility. Company management requested the evaluation due to a high incidence of musculoskeletal disorders mat were thought to be job related. Ergonomic assessments of selected jobs in raw material handling, sawing operations, frame assembly, sanding and painting, cabinet assembly, and the packaging-shipping departments were performed. Company log of injuries and company injury surveillance data were reviewed. Jobs were identified that imposed potentially stressful biomechanical demands on the workers. These included heavy lifting, pushing and transporting heavy loads, fatiguing postures, repetitive lifting involving twisting the trunk and excessive reaching, and repetitive motions of the trunk and upper limbs. Survey data indicate that manual material handling jobs, repetitive motion tasks, and operation of saws, planers, and sanders are potential hazards. Recommendations to reduce injury risk are to provide basic safety training for all employees, and redesign equipment to reduce stress during heavy lifting, transporting loads, and while performing repetitive tasks.
Static Force Exertion in Standardized, Functional and Free Postures
Authors: Daams Brechtje J.
Published: January 2012

In assessing human force exertion, the use of standardized postures can lead to inaccurate prediction of the forces and postures which occur in everyday life. Force data obtained using postures freely chosen by the subjects themselves may therefore be considered more relevant. A carefully standardized posture, however, is generally considered to yield more reliable data. The question arose whether it would be possible to combine the two in some way, calling the result a “functional posture”. Research was necessary to determine a way of operationalizing these functional postures, and to test their reproducibility.

First, a method is proposed to describe functional postures through explorative research. This includes the fixation of members that transfer force to the outside world, while the rest of the body is allowed to move freely. The results of further research show that the exerted force is reproducible in free, in functional, and in standardized posture. The difference in average force, though, is considerable and significant. The conclusion is that force exertion in free posture is most appropriate for design research.
The Development of Ergonomic Guidelines for Railroad Hand Switch Operation
Authors: Page George B. , McMahan Paul B. , Brown R. Todd , Kerk Carter J.
Published: January 2012

Injury statistics and worker perceptions of relative task difficulty and frequency suggest that the operation of hand switch stands/switches may be a problem task in the railroad industry (Kuciemba, Page, and Kerk, 1988). Injuries associated with this task are mostly over exertion in nature, 43% of which occur to the lower back. This paper describes how we developed ergonomic guidelines specifically to address hand switch operation. These guidelines could be applied to: identify switches that may pose excessive risk of injury when operated, evaluate maintenance procedures, and assist in developing switch stand design alternatives.

The guidelines specifically define hand forces across the range of switch lever motion encountered when operating the switch stand. There are two sets of guidelines, lower guidelines and upper guidelines. The lower guidelines are defined by the back compression and static strength criteria NIOSH (1981) uses to define their Action Limit, along with a stability criterion. The upper guidelines are defined by the same two criteria NIOSH (1981) uses to define their Maximum Permissible Limit, along with the stability criterion.

We videotaped 20 workers operating 50 different switches at 3 different rail yards to classify worker methods into general categories. Then the postures associated with each of the general methods were recreated using 5th and 95th percentile workers, photographed, and digitized for use in the University of Michigan 3D Static Strength Prediction ProgramTM. For each posture, we then calculated the maximum hand forces that separately satisfied the lower and upper criteria. The maximum hand forces under the two sets of constraints define our guidelines.
Human Factors: Added Value to Retail Customers
Authors: Sluchak Thomas J.
Published: January 2012

This paper describes the role played by Human Factors in providing ergonomic added value to IBM customers in the retail point-of-sale area. Serving primarily in a consulting role, Human Factors assists the retail customer in the areas of cashier workstation analysis and redesign, field evaluation of equipment, employee training, on-line interface design, and education in other ergonomic-related topics. Human Factors expertise in task analysis, anthropometry, experimental design, and data analysis, combined with engineering tools such as computer-aided design, has proved to be much desired among retailers. The added value perceived by the retailer from the services and expertise provided by Human Factors is matched by the benefits perceived by Human Factors from its increased knowledge and experience in the retail area.
The Development of Preparatory Response Strategies in Anticipation of Sudden Loading of the Torso
Authors: Lavender Steven A.
Published: January 2012

A common theme found in epidemiological studies is the occurance of low back injuries where the body is required to quickly generate muscular forces necessary for stabilizing the body, as in the case of slips, falls, and sudden loading. These large muscular forces create large instantaneous loadings on structures within the musculoskeletal system, including the spine. This is viewed as a mechanism whereby low back injury occurs. Previous investigations have indicated the importance of a preparatory period in reducing the impulse loads delivered to the spine. The current research was designed to address questions as to how cognitive factors, such as temporal expectancies, enable the body to prepare for a loading event. Four subjects were exposed to repeated sessions of sudden loading at 1 minute intervals. This experiment measured: the muscle responses via surface EMG, IAP, and postural changes made in anticipation of the loading event. The preparatory strategies were evaluated in terms of: the predicted spinal compression, sagittal lumbar displacement, COG displacement and ground reaction forces.
Symmetric and Asymmetric Stoop-Lifting Strength
Authors: Kumar Shrawan
Published: January 2012

The strength capability of workers is an essential design criterion. Though true job simulated strength is most appropriate, availability of strength values in many standardized postures will permit selection of most suitable or a series of suitable strength values. Six normal young male subjects performed a maximal lifting effort in a stooping posture in isometric (with hip angles 60° and 90° flexion) and isokinetic modes (50 cm per second linear velocity). The isokinetic lift was performed from floor to knuckle height. Each lift was performed at half, three-quarters, and full reaches by each subject in sagittal, 30° lateral and 60° lateral planes. The strength was measured using the Dynamic Strength Tester (DST) described by Kumar et al (1988). The strength was inversely related to reach distance (p<0.0001). The largest declines in strength were between half and three-quarters reach distances (45% to 50%). From three-quarters reach to full reach, the drop was between 10% to 30%. With increasing asymmetry, the strength declined significantly (p<0.0001). The extent of this decline decreased at longer reaches. Based on these findings, a case is built for a biomechanical standardization of strength measurements.
Human Force Exertion the Influence of the Direction of the Effort
Authors: Hennion P.Y. , Coblentz A. , Mollard R.
Published: January 2012

Although the concept of human force exertion appears a rather simple one, its measurement rises many problems. In a precedent work we have underlined the fact that the result of the effort exertion is widely conditioned by the experimental protocol that is used, including factors as vocal stimulation, visual control feed back, time duration or else… We retained for standard conditions of exerting a pulling effort on a fixed handle, without displacement, an arrangement that provides to the subject a real time visual display of the effort recording on a scope placed in front of him. This method gives sufficiently stable and reproductible data for a systematic study. The following step of this study is evaluating the force exerted at different locations around a seated subject. In this case, a new problem appears: what should be the direction of the pulling effort, related to a reference frame linked to the seat, which is equally a standard anatomical reference system for the subject belted on this seat. Two extreme choices are possible. The first one corresponds to classical industrial arrangements when the handle remains horizontally perpendicular to a frontal plane and constitutes an imposed condition. The other possibility is to let the subject free to choose the direction of his pulling effort. The present paper accounts for a comparison of these two conditions for five azimutal positions of the handle varied in the horizontal plane of the right acromion, at such a distance that in the final position the right upper limb is straight. The results for sixteen male subjects exhibit a significant degradation of the efficiency of pulling in the imposed procedure compared with the choosen one. This discrepancy is growing with the increase of the azimutal angle.
Isokinetic Wrist Strength of Females with Carpal Tunnel Syndrome
Authors: Fernandez Jeffrey E. , Klein Mary G. , Learned Valerie , Marley Robert J.
Published: January 2012

An experiment was conducted to determine isokinetic wrist flexion and extension strengths of females diagnosed with carpal tunnel syndrome (CTS). Static strength measures were also documented. These values were compared to values from a matched control group. Results show a significant reduction in isokinetic wrist flexion force, grip and tip pinch strengths within the CTS group compared to the controls. Range of motion in wrist flexion also showed a significant decrement for the CTS group. Finally, regression models were developed to predict isokinetic strength based upon static measures.
Hand-Handle Orientation and Maximum Force
Authors: Hallbeck M. S. , Cochran D. J. , Stonecipher B. L. , Riley M. W. , Bishu R. R.
Published: January 2012

Many industries today have very high incidence rates for cumulative trauma disorders (CTD). Several factors are known to contribute to the onset of CTDs including the application of high forces. A reasonable inference is that a tool and/or task design that requires less grasp muscle effort will be less likely to contribute to CTD. The findings of a study by Jorgensen et al. (1989) indicated that the direction of power grasp force relative to the hand appears have a significant effect on the magnitude of the force exerted. This study was conducted to confirm and quantify these force magnitude differences for four orientations of opposition forces to the hand in a power grasp for two friction conditions and two handle shapes. The results showed that the orientations can be placed in two groups, one containing a single orientation and the other grouping containing the remaining three orientations. The orientation found to be superior to the other three was the pull resisting a force at the bottom of the hand (nearest digit 5). In this orientation, the hand is better able to oppose forces acting at the hand-handle interface than in two of the other orientations. The results of this research indicate that avoidance of the inferior orientations (those acting to ulnarly deviate the wrist) will be beneficial. Because current jobs are designed without considering the force direction, workers are exposed to unnecessary stresses. This study will give work task designers one more piece of information to help reduce the stresses on the hand and wrist.
Overview of Management and Organizational Effects on Industrial Safety
Authors: Schurman Donald L. , Kramer Joel J.
Published: January 2012

A number of industrial accidents of large magnitude and involving a large number of deaths or great financial loss have contributed to increased awareness that high technology poses great risks of accidents becoming disasters. Concurrently with, or perhaps because of, this increased awareness of the risks of high technology has come increased awareness that the organizations and people who manage this high technology often contribute to, rather than ameliorate, those risks. The symposium papers report on some research efforts to examine, understand, and evaluate the contributions of organizational and management to risk and safety.
Influence of Organizational Factors on Safety
Authors: Haber Sonja B. , Metlay Daniel S. , Crouch Deborah A.
Published: January 2012

There is a need for a better understanding of exactly how organizational and management factors at a nuclear power plant (NPP) affect plant safety performance, either directly or indirectly, and how these factors might be observed, measured, and evaluated. The purpose of this research project is to respond to that need by developing a general methodology for characterizing these organizational and management factors, systematically collecting information on their status and integrating that information into various types of evaluative activities. Research to date has included the development of the Nuclear Organization and Management Analysis Concept (NOMAC) of a NPP, the identification of key organizational and management factors, and the identification of the methods for systematically measuring and analyzing the influence of these factors on performance. Most recently, two field studies, one at a fossil fuel plant and the other at a NPP, were conducted using the developed methodology. Results are presented from both studies highlighting the acceptability, practicality, and usefulness of the methods used to assess the influence of various organizational and management factors including culture, communication, decision-making, standardization, and oversight.
MANPRINT Enhancement Methods: Organizational Change Process Review
Authors: Peters Joseph I. , Masterson Stephen P. , Hewitt Glen
Published: January 2012

The Army has developed a program to improve the effectiveness of the systems it procures by considering human factors very early in the system acquisition cycle. This program is called “MANPRINT,” and was established in approximately 1985 as a top-down management initiative by the Chief Of Staff of the Army. MANPRINT is an acronym that stands for “MANpower and PeRsonnel INTegration.” The creation of MANPRINT within the Army has had a significant impact on both the structure of the Army organization and the procedures by which systems are acquired.

The US Army has commissioned a study to evaluate the effectiveness of the MANPRINT study and to make recommendations for its enhancement. A major purpose of this study is to assess the degree to which the MANPRINT program has been adequately instituted and incorporated into the organizations and operations of the combat development and materiel acquisition communities. Another purpose is to evaluate the degree to which the MANPRINT program targets those who are accountable for design trade-off decisions involving MANPRINT issues, and the implications for improving MANPRINT.

An organizational design of the MANPRINT program will be presented with positive and negative constructive criticism. Statistics describing the sample will be presented. A content analysis of interview results will be presented, and questionnaire results will be presented in appropriate graphical format. The presentation will conclude with recommendations for enhancing the MANPRINT organization.
The Adjustment to a Slowly Rotating Shift Schedule: Are Two Weeks Better than One?
Authors: Duchon James C. , Keran Christopher M.
Published: January 2012

The Bureau of Mines is examining alternative rotating work schedules that are more conducive to the health and safety of mining shiftworkers. The question asked in this study is whether or not there is an advantage to working the second week of a two week cycle, as would be indicated by reports of more positive health, mood and sleep items on the second week as compared to the first week. Forty-two workers at a surface mine in the midwest filled out the Work, Food and Sleep Diary for four to six weeks. They rotated every two weeks going from days to nights to afternoons with all weekends off. The dependent measures were defined as 1) health: the daily frequency of reported symptoms 2) mood: based on a self-evaluation of four descriptors, ALERT, SLEEPY, GROUCHY, and RELAXED, 3) total sleep length and sleep quality. Results indicated that on the second week of the night shift workers reported significant improvements in all four mood descriptors for the second half of their shift. Also, sleep quality as measured by awakenings during sleep improved on the second week of the night shift. None of the variables showed a worsening on the second week of the night shift. These results do not support a “cumulative trauma” effect for the schedule studied in this paper. On the basis of this study it could be recommended that two week cycles are superior than one week cycles.
Macroergonomic Considerations in Determining Minimum safe Crew Size on Maritime Vessels
Authors: Hendrick Hal W. , Grabowski Martha
Published: January 2012

As part of a National Research Council project, a study was undertaken to develop and initially validate a function analysis model for determining the minimum safe crew size of maritime vessels. During the validation phase, macroergonomic factors were identified which must be specified in using the model. These factors and their effects on manning are reviewed.
Modeling Individual Differences at a Process Control Task
Authors: Lewis C. Michael
Published: January 2012

Individual differences at process control tasks are difficult to analyze because similar system performance may result from different control strategies. This paper introduces a methodology for describing rule and skill based components of performance directly, using machine learning techniques. Similarity among strategies is shown to have a greater effect on performance than training interventions. The behavior of two subjects who are nearly identical in performance but vary greatly in strategy is examined to illustrate the potential of this approach for assessing individual differences at process control tasks.
Emerging Methodologies for the Assessment of Safety Related Product Communications
Authors: Rhoades Timothy P. , Frantz J. Paul , Miller James M.
Published: January 2012

The analysis and prevention of accidents often addresses issues related to compliance with product usage and cautionary information found on the product and within its accompanying manual. The actual knowledge applied when using a product, however, likely comes from many other sources in addition to (or instead of) these sources. In cases where inappropriate knowledge is applied to the use of a product, an injury, property damage, or substandard output may occur. This being the case, the development of a product and its accompanying information should consider user knowledge and patterns of behavior in the absence or partial absence of printed product information. Contemporary guidelines for safety related communications, however, emphasize the physical features and content of product information rather than formal analysis of user characteristics.

To address these concerns, this paper suggests methods which may be further developed and validated to predict product usage behaviors and user interpretation of product information. The authors present applications of word association methods, semantic features analysis, and script analysis using a case study approach. In situations where undesired behavior is predicted, the authors suggest that user analysis may often indicate countermeasures other than the simple addition or alteration of written product information.