Alan Hedge

• Doctor of Philosophy
• Professor (Full) at Cornell University

Objective Compare musculoskeletal discomfort, productivity, postural risks, and perceived fatigue for a sit-stand-walk intervention between two workstation configurations – one, individually customized for office workers according to ergonomic guidelines (Ergo-Fit); another, self-adjusted by office workers according to their preference (Self-Adjust...

The effects of a sit-stand-walk intervention to reduce musculoskeletal discomfort, attenuate perceived physical and mental fatigue, and increase physical activity without adversely affecting productivity was investigated for computer-based work. A between-participants design was used with 80 participants randomly assigned to one of five work condit...

Virtual Reality-based Learning Environments (VRLEs) are an emerging tool for classroom teaching. While VRLEs are increasingly in use, little attention has been paid to ergonomic challenges in use of VRLEs. This study compared two 3D interface designs of a VRLE created to teach the phases of the Moon. Participants ( N = 16) were randomly assigned to...

Active seating designs may enable users to move more frequently, thereby decreasing physiological risks associated with a sedentary lifestyle. In this preliminary study, two active seating designs (QOR360, Ariel; QOR360, Newton) were compared to a static chair (Herman Miller, Aeron) to understand how active vs. static seating may affect task perfor...

The micro-environment in this study refers to the air space and environment around a person that directly impacts their thermal sensation. This study aims at evaluating the performance of a newly developed micro-environmental control system (μX) designed to cool the occupants locally for thermal comfort when the temperature in the ambient unoccupie...

This pilot study compared cognitive performance in short-duration computer-based tasks between static sitting as control, and active sitting with use of a dynamic foot movement device as intervention. Using a within-subjects counterbalanced design; participants performed four computer-based tasks evaluating cognitive performance. A survey reported...

Occupant surveys were conducted in 4 office buildings, 2 with traditional non-tinted low-e glass (LeG) and 2 with electrochromic glass (EG). 106 employees working in these buildings volunteered to participate in the study. Results showed that subjective reports of overall ambient lighting conditions were comparable in the buildings. However, EG opt...

This study aims at developing a Cooling/Heating Delivering Device (CDD/HDD) for a micro-environmental control system (μX) to restore occupants’ thermal comfort when the building indoor temperature thermostat is expanded from 21.1-23.9 °C (70.0-75.0 ℉) to 18.9-26.1 °C (66.0-79.0 ℉) to reduce HVAC load. A comprehensive methods was implemented for the...

This study evaluated the effects of active versus static standing on short-duration computer task performance, postural risks and perceived pain, comfort and fatigue. A repeated measures, within-subjects study was conducted in which 16 participants performed 40 trials of a computer-based homing task in two active standing versus a static standing c...

This study evaluated the effects of active and static sitting chairs on short-duration computer task performance, postural risks and perceived pain, comfort and fatigue. A repeated-measures, within-subjects study was conducted, in which 16 participants performed 40 trials of a computer-based homing task in four seating conditions. Computer task per...

The dissipation of heat from a tablet computer can be a limiting factor for hardware design, and this is affected by power consumption, the central processing unit (CPU) and the thickness of the casing. If the tablet casing gets too hot it affects user’s thermal comfort and may even cause skin burns. Consequently, this study investigated the effect...

The study investigated how the material roughness of a tablet computer surface can affect thermal sensation and comfort of users fingers and palms at different surface temperatures. Three levels of pattern spacing were tested, and it was shown that rough material surface provided higher thermal comfort comparing to a smooth surface. In addition, th...

Past research has shown that the rate of change of skin surface temperature can affect thermal sensation. This study investigated users’ thermal responses to a tablet heating surface with different heat pads and different temperature change rates. The test conditions included: A. keeping the surface at a constant 42 °C, B. increasing the surface te...

Literature was reviewed and summarized on a few topics including: existing standards about the limits of devices' surface temperature, recent studies on the devices that caused discomfort and skin damage, human thermal sensation thresholds, the factors that affect thermal sensation, and the subjective ratings in the studies of thermal sensation. At...

Background: There is a need to better understand the perceived experiences of workers in green buildings as the literature to this point has been mixed. Objectives: To re-evaluate occupant experiences within a LEED platinum building and investigate current experiences in general. Methods: An online post occupancy evaluation (POE) survey of 62...

BACKGROUND: Laptop computers have surpassed desktop computers in popularity, especially among college student users. The portability of these devices raises concerns regarding healthy usage patterns in different settings and there is a need to investigate the postures with which these devices are being used and associated reports of musculoskeletal...

Past research has shown that the rate of change of skin surface temperature can affect thermal sensation. This study investigated users’ thermal responses to a tablet heating surface with different heat pads and different temperature change rates. The test conditions included: A. keeping the surface at a constant 42°C, B. increasing the surface tem...

The study evaluated effects of sitting and standing work postures on objective short-term computer typing performance and perceived discomfort. A randomized, repeated measures, study design was used to assess typing performance and perceived discomfort for 12 participants on a 15-minute computer-typing task. Typing performance was measured by numbe...

This study tested user knowledge and the use of the controls for their work chairs for a volunteer sample of 1004 office workers who were randomly selected for survey from 23 different companies and who were sitting on one of a total of 60 different ergonomic office chairs. Results showed that with the exception of seat height and armrest adjustmen...

Background: This study compared the effects of pre-experience and expectations on participant comfort upon waking, arrival to, and after an appointment, as well as the assessment of properly placed Feng Shui elements in three healthcare waiting rooms. Methods: Participants assessed comfort levels using self-report surveys. The researcher conduct...

The article link will provide free access to this article, and is valid for 50 days, until January 20, 2016 http://authors.elsevier.com/a/1S7nT_3t7B08L7

A series of experiments was conducted to investigate participant thermal responses to different surface temperatures, from 34 to 44 °C, for a simulated tablet computer in different ambient temperatures (13 °C, 23 °C, and 33 °C). Two subjective measures, thermal sensations and thermal comfort, were reported by the participants. Within the same ambie...

This monograph lays out a discussion framework for understanding the role of human-computer interaction (HCI) in public policymaking. We take an international view, discussing potential areas for research and application, and their potential for impact. Little has been written about the intersection of HCI and public policy; existing reports typica...

This monograph lays out a discussion framework for understanding the role of human-computer interaction (HCI) in public policymaking. It takes an international view, discussing potential areas for research and application and their potential for impact. The aim is to provide a solid foundation for discussion, cooperation and collaborative interacti...

This paper focuses on the ergonomics evaluation of Medical Tablet Personal Computers (MTPCs). The research questions for the study were “What are the key ergonomics issues in the safe and effective use of a Medical Tablet PC” and “How can we evaluate new Medical Tablet PC concepts in the early stages of the design process”. The aims of the study we...

An international group of experts convened to provide guidance for employers to promote the avoidance of prolonged periods of sedentary work. The set of recommendations was developed from the totality of the current evidence, including long-term epidemiological studies and interventional studies of getting workers to stand and/or move more frequent...

A tablet computer’s surface temperature can reach levels that can lead to user discomfort, especially in a warm environment. The ambient environments in which tablet computers are used can also vary. To understand how users perceive the heat from tablet computers, a laboratory study was conducted with controlled surface temperatures and ambient tem...

New ways of work are rapidly changing globally wherein employees can work anywhere at any time. Virtual teams and telework are a common alternative worksite where employees are typically using a computer and mobile device to conduct their work. Satellite office workspaces are prevalent with workers are having sharing desks, or hoteling. With mobile...

The effect of using a mouse, a trackpad and a 3D motion-and-gesture control (3DMGC) on point-and-click task performance, posture and comfort was tested with twelve participants. Performance (movement time, throughput, error); wrist and arm posture; comfort and usability ratings were recorded. Results showed that for performance measures, the mouse...

It has been reported that tablet computer surface temperatures can rise from room temperature up to 47°C. Holding a warm or hot computer surface might cause user’s thermal discomfort and possibly skin burns. The use of a tablet often requires holding the device for prolonged time with multiple fingers and palm areas in contact with the tablet lower...

Train driving is a highly visual task. The visual capabilities of the train driver affects driving safety and driving performance. Understanding the effects of train speed and background image complexity on the visual behavior of the high-speed train driver is essential for optimizing performance and safety. This study investigated the role of the...

This study developed an ergonomic evaluation system for the design of high-altitude partial pressure suits (PPSs). A total of twenty-one Chinese males participated in the experiment which tested three types of ergonomics indices (manipulative mission, operational reach and operational strength) were studied using a three-dimensional video-based mot...

A study on capstan partial pressure suits (PPSs) was conducted to determine their effects on pilots' operational performance on a series of ergonomic measures at different pressure levels using objective and subjective approaches. Tests of range of motion, operational performance and operational strength were carried out on ten male subjects wearin...

The survival of (Escherichia coli, Pseudomona aeruginosa, and Staphylococcus aureus was tested on natural beech wood, varnished beech wood, and plastic at 5 times:immediately after surface contamination and drying; 24 and 48 hours after contamination; 24 hours after contamination the samples were cleaned with non-germicidal detergent cleaner (Trito...

A survey of 204 health professionals (physicians, physicians’ assistants and nurse practitioners) in private diagnostic clinics of a major healthcare system was conducted after the introduction of an electronic health records (EHR) system. Results showed considerable daily use of computers in various configurations and some 90% of respondents said...

The heat from some laptop computers has resulted in reports of toasted skin syndrome and even skin burns. Although standards exist to limit the maximum temperature of electronic devices to prevent skin burns, few studies have been done on the thermal discomfort associated with laptop heat production. Consequently, a survey and temperature measureme...

Laptop use is associated with a number of musculoskeletal risk factors, however there is a deficit of research pertaining to their use in any context other than a traditional desk and chair. Because laptops are designed to be portable, they are utilized in a wide variety of configurations, some of which may place the user at risk of injury. The cur...

This study investigated the role of the location updating effect (the memory deficit associated with passing through a doorway) and input technology (paper, a tablet PC or a laptop) on working memory for medical charting information, because in many hospitals physicians and nurses often leave the patient bedside to enter their medical information e...

Over 200 employees at a software company completed comprehensive surveys before and after moving to a new headquarters building with customized ergonomic workstations. The company has a proactive ergonomics program and all employees received ergonomics training. Questions asked about features of their workstations, workplace environment, work-relat...

Background: Green building standards are significantly impacting modern construction practices. The resulting structures are more energy efficient, but their impact on occupant health has not been widely studied. Objective: To investigate a range of indoor environment and ergonomic issues in green buildings. Methods: Retrospective post-occupan...

In the past decade the green building movement has gathered tremendous momentum. Since 2008 the US Green Building Council has provided an opportunity for ergonomists to actively participate in this movement by helping designers earn credit in the Leadership in Energy and Environmental Design (LEED) certification process. This paper outlines the his...

Ergonomics surveys were conducted in a software company with a proactive ergonomics program before and after moving to a new headquarters building in which workstations were equipped with ergonomic products. Sixty-seven workers voluntarily completed surveys of their workstations, workplace environment, work-related health and well-being (job satisf...

Modern radiology is digital and the work of the radiologist now shares many features with that of other high technology computer work. Many digital reading rooms are poorly designed in terms of ergonomics and how they accommodate computer technology. Lighting is typically inadequate resulting in visual health problems of eyestrain and headaches and...

Public policy increasingly plays a role in influencing the work that we do as HCI researchers, interaction designers, and practitioners. "Public policy" is a broad term that includes both government policy and policy within non-governmental organizations, such as standards bodies. The Interacting with Public Policy forum focuses on topics at the in...

BACKGROUND: Students are faced with work demands requiring intense computer use throughout the week, often with cumulative hourly use per day exceeding that of adult workers. Extended daily computer use has been associated with a reported increase of musculoskeletal symptoms for college-aged students. New mouse designs offer alternative movement an...

Background: Assessing physical ergonomic factors within the classroom environment creates new opportunities to support designs that promote student well-being. Student-aged anthropometric data helps guide proper desk fit assessment, therefore facilitating scholastic performance through the reduction of distractions such as physical discomfort. Ob...

A survey of 2,346 office computer users was analyzed using structural equation modeling to identify self-report individual, work characteristics, technology, and postural risk factors, determined by observation, for self-reports of work-related musculoskeletal discomfort for the neck, shoulders and arms/hands and also somatic symptoms (eyestrain, h...

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 mo...

Partial pressure suits (PPSs) are used under high altitude, low-pressure conditions to protect the pilots. However, the suit often limits pilot's mobility and work efficiency. The lack of ergonomic data on the effects of PPSs on mobility and performance creates difficulties for human factor engineers and cockpit layout specialists. This study inves...

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...

Unlabelled: A retrospective post-occupancy evaluation survey of 44 occupants in two Leadership in Energy and Environmental Design (LEED) Platinum buildings on a US college campus is reported. The Internet survey covered a range of indoor environment and ergonomics issues. Results show that working in these buildings were a generally positive exper...

Infographics are designed graphic visual representations of information, data or knowledge that combine symbols, visual imagery, text, and data in innovative ways in order to quickly and clearly convey complex information to viewers. Increasingly infographics are being used on the web yet little systematic investigation has been undertaken on the m...

Reading room design can have a major impact on radiologists' health, productivity, and accuracy in reading. Several factors must be taken into account in order to optimize the work environment for radiologists. Further, with the advancement in imaging technology, clinicians now have the ability to view and see digital exams without having to intera...

This study provides an historical and statistical analysis of archival data from the Hawthorne illumination experiments. Previous accounts of the illumination experiments are fraught with inconsistencies because they have been based on secondary sources. The general consensus has been that variations in light levels had no effect on worker producti...

Workers in a New York City department participated in an office ergonomics training program and voluntarily completed a survey of work-related musculoskeletal symptoms (WRMSs). Results of the survey were used to guide ergonomic interventions and sixty days later employees voluntarily completed a follow-up WRMS survey. Complete data for full-time em...

An ergonomics survey of 84 employees who moved to an alternative workspace with smaller workstations equipped with various ergonomic products is reported. Half of the employees received some ergonomics training. Results showed that 25-40% reported the ergonomic products were somewhat or much less comfortable to use, and around the same proportion f...

The United States healthcare system is transitioning from paper-based to computer-based systems. In this process, it is vitally important to focus on optimizing the role of human factors in systems design. This review examines a wide range of cognitive ergonomics and socio-technical systems issues that impact the successful implementation of health...

The US healthcare industry is poised on the verge of a massive expansion of its information technology infrastructure. Healthcare information technology (IT) is permeating numerous areas of healthcare delivery and fundamentally changing the nature of many healthcare jobs. When a comparable expansion in HIT use occurred in the office environment in...

Effects of indoor environment on the performance of creativity and productivity were studied in a simulated office with an outdoor airflow rate of 5 or 20 L/(s·p), with other environmental parameters constant. The research was conducted with twenty subjects performing a series of computerized tasks, consisting of creativity tasks (Compound Remote A...

Certification in the LEED rating system for green buildings traditionally has focused on strategies for increasing energy efficiency and lowering indoor air pollutant emissions by selecting appropriate and natural or recyclable materials. However, designing an energy efficient workplace and low pollution workplace doesn't necessarily equate with cr...

The effect of using five different optical mice on cursor positioning task performance and on wrist posture was investigated. The 5 mouse designs included 1 conventional mouse, 2 angled mice and 2 vertical mice. Results showed that performance was significantly different for the 5 mice for the cursor point-and-click tasks and cursor dragging tasks....

This paper describes a menu-driven ergonomic expert system, SONEX, that is based on knowledge of work-related musculoskeletal risk factors and expert opinion. The software is easy to use, by experts and layman. Risk factors are divided into two main knowledge bases and four additional bases, and each of them is a separate expert system. The SONEX s...

Nineteen employees performing comparable sales order-entry tasks participated in a study of the effects of the environmental conditions at their workstations on their computer work performance. Air temperature, relative humidity, carbon dioxide, total volatile organic compounds, and respirable particulates at 10 microns were logged at each workstat...

The concept of personal control is examined as this relates to the conceptual design of personal ventilation systems based upon the body's physiological and psychological homeostatic requirements. Literature on the effects of personal control of environmental conditions is reviewed. The concept of a “just noticeable difference in discomfort” that u...

A field study of 16 people in a law office was conducted. Environmental conditions, air temperature, relative humidity, carbon dioxide (CO2), respirable particulates at 10 microns (PM10) and total volatile organics (TVOC), at each person's workstation were recorded at one-minute intervals for 4 weeks. Synchronous measures of computer work performan...

The use of ramps to improve building accessibility for wheelchair users is required by the Americans with Disabilities Act, the Fair Housing Act, and various building codes, all of which specify requirements for ramp design, including their maximum running slope and cross slope. Design recommendations for either the running slope or the cross slope...

Sixteen employees participated in a one-month study of the effects of environmental conditions at their workstations on their computer work output. Air temperature, relative humidity, carbon dioxide (CO2), respirable particulates at 10 microns (PM10) and total volatile organics (TVOC) levels were logged at each workstation. A web-based software sys...

The concept of personal control as this relates to the design of a personal ventilation system is critically examined. The concept of a "just noticeable difference in discomfort" that underpins the desire to initiate some personal control action is described. It is proposed that the concept of personal control is symmetrical for thermal conditions,...

This study tested the effect of acute exposure to a commercial air freshener, derived from fragrant botanical extracts, at an average concentration of 3.16 mg/m3 total volatile organic compounds on the lexical decision performance of 28 naive participants. Participants attended two 18-min sessions on separate days and were continuously exposed to t...

Abstract The recent conference on Indoor Air Quality, Immunity and Health (June 1995) held at North Carolina State University, Raleigh, North Carolina, and cosponsored by the Cornell University Institute for Comparative and Environmental Toxicology, the Cornell Center for the Environment, and North Carolina State University provided an opportunity...

This study compared typing performance using a laser projection virtual keyboard (VKB), and an electromechanical folding keyboard (FKB). Twenty undergraduate students (10 male, 10 female) participated as subjects in the study. Typing performance was measured for twelve 7.5-minute typing trials for each of the two keyboards. The results showed that...

This study examined the impact of front-end, web page usability guideline implementation on aesthetic evaluations of e-commerce web pages and perceptions of the e-retailer. Four design factors (background color, white space, thumbnail image location, and thumbnail image size) were selected and varied based upon an in-depth review of the usability,...

Eleven subjects, 5 male and 6 female, all with back pain, performed 3 × 10-minute tasks separated by 2 × 10-minute relaxation tasks, while sitting for one 1-hour session on a rotary dynamic seat (DS). Ss preferred different speed settings depending on task. Ss chose to have no motion (speed setting 0) for "active tasks" (writing, typing, and using...

Legal and operational definitions of health, safety, and welfare are expanding to include greater emphasis on long-term issues of health and psychological well-being in addition to near-term safety issues. Mounting environmental research suggests that many interior design decisions previously thought of as benign with respect to their effects on hu...

The effects of installing a flat panel monitor arm (FPMA) at an architecture firm were investigated. Twenty eight participants were equally divided into test and control groups. Three surveys were conducted: pre-installation and one-month and 3-month post-installation. The web-based survey assessed musculoskeletal discomfort for eleven upper body r...

Thirty-six subjects, half with back pain, performed 1-hour sessions, including 3 × 10-minute tasks separated by 2 × 10-minute relaxation tasks, while sitting on both a static seat (SS) and a rotary dynamic seat (DS) at fixed speed. Ss torso movement was greater for the DS condition (p=.000) and while performing active versus passive tasks (p=.000)....

This study investigated the effects of a computer mouse that vibrates after 10 seconds of inactivity to remind the user to release their grip and rest their hand. A laboratory experiment tested the reactions of 11 female and 7 male participants to this vibrating mouse against a conventional mouse to see how it affected Ps performance of 5 tasks, th...

A 3D whole-body laser scanning method was used to evaluate the deformations of flexible material chair backs. Twenty-four Ss of different gender and body sizes sat in each of two ergonomie chairs (B, G). 3D images were analyzed for volumetric deformations. The chair back was divided into an upper region (from the lumbar through the thoracic to the...

Survey data on the effects of an office ergonomic intervention (negative-tilt keyboard tray, upper mouse platform, chair, and training) were analyzed. Baseline and one-year post-intervention data on work activities, individual factors and the frequency and severity of upper body work-related musculoskeletal disorders (WMSDs) were compared. Results...

Residues for 17 pesticides were analyzed in 41 households in central New York State that represented farm, rural, and urban houses. Samples were taken in both summer and winter of 2000-2001 from the same households from four locations; family room carpet; adjacent smooth floor; flat tabletop surface; and settled dust collected in a Petri dish on a...

The effects of foam, mesh and gel chairs on thermal comfort and productivity were investigated. Thirty-six subjects, 18 men and 18 women, were tested in same-sex triads with each subject sitting on one of the 3 chairs for 1.5 hours. Subjects wore light clothing (shorts, t-shirt, socks and sneakers) with a low clo value. Skin and body temperature we...

This study investigated the effects of a claimed ergogenic aid, peppermint odor inhalation, on running performance, under different experimenter-induced odor expectancy conditions. Eighteen fit, young women subjects performed 3 × ¼-mile runs, under three randomly assigned treatments: peppermint-scented mask; unscented mask; and no mask. Each subjec...

The effects of using an electric height-adjustable worksurface, with and without the addition of a negative-tilt keyboard tray, on wrist posture, comfort, typing performance and body movements was studied. Eighteen subjects experienced four test conditions: typing while sitting with the keyboard on a flat surface or negative tilt keyboard tray, and...

A field study was conducted to investigate the associations between indoor thermal conditions and productivity for computer workers in an insurance company. Thermal environment conditions and productivity were logged every 15 minutes for 9 women workers for 16 consecutive work days. Results showed an association between thermal conditions and produ...

This study compares the use of a conventional keyboard (CK) and a prototype ultra-low profile MultiTouch keyless keyboard (MTK) that only requires contact force to register a keystroke and allows mousing and gestural input on the same surface. Twelve subjects completed eight randomly assigned 7.5-minute typing tasks of text passages of similar diff...