There have been a variety of research approaches that have examined the stress issues related to human computer interaction including laboratory studies, cross-sectional surveys, longitudinal case studies and intervention studies. A critical review of these studies indicates that there are important physiological, biochemical, somatic and psychological indicators of stress that are related to work activities where human computer interaction occurs. Many of the stressors of human computer interaction at work are similar to those stressors that have historically been observed in other automated jobs. These include high workload, high work pressure, diminished job control, inadequate employee training to use new technology, monotonous tasks, poor supervisory relations, and fear for job security. New stressors have emerged that can be tied primarily to human computer interaction. These include technology breakdowns, technology slowdowns, and electronic performance monitoring. The effects of the stress of human computer interaction in the workplace are increased physiological arousal; somatic complaints, especially of the musculoskeletal system; mood disturbances, particularly anxiety, fear and anger; and diminished quality of working life, such as reduced job satisfaction. Interventions to reduce the stress of computer technology have included improved technology implementation approaches and increased employee participation in implementation. Recommendations for ways to reduce the stress of human computer interaction at work are presented. These include proper ergonomic conditions, increased organizational support, improved job content, proper workload to decrease work pressure, and enhanced opportunities for social support. A model approach to the design of human computer interaction at work that focuses on the system "balance" is proposed.

The purpose of this study was to examine differences in experienced typists' performance, posture, and musculoskeletal pain when using a split, adjustable (SA) computer keyboard and when using a standard flat keyboard. In addition, the use of a wrist rest was examined for performance, posture, and musculoskeletal pain effects. Eighteen participants were exposed to the SA keyboard and a flat keyboard in a laboratory study of text typing for four consecutive hours on five days. The results indicated that after just 2 h of orientation and practice, the participants could perform as well on the SA keyboard as on the flat keyboard. The SA keyboard provided advantages for reduced wrist/hand pronation. There was no difference between the keyboards in the level of musculoskeletal pain reported by participants after typing. However, they reported increased pain in the back, neck, shoulders, and wrists from the beginning to the end of each of the experimental periods for both keyboards.

According to the International Labour Organization (ILO, 19981, about 250 million workers worldwide are injured annually on the job, 160 million suffer from occupational diseases, and approximately 335,000 workers die each year from occupational injuries. In the United States alone, it was estimated that in 1992 the direct costs of occupational injuries and illnesses (e.g., medical, property damage) totaled $65 billion and the indirect costs (e.g., lost earnings, workplace training and restaffing, time delays) totaled $106 billion (Leigh, Markowitz, Fahs, Shin, & Landrigan, 1997). Although agriculture, commercial fishing, construction, and mining surpass manufacturing in the number of fatalities and serious injuries, manufacturing has a higher than average injury rate in developed countries. This chapter will examine the causes of occupational injuries and illnesses and ways to reduce worker risk. It will provide direction for establishing effective detection and control methods. Additional resources are provided throughout the chapter for more detailed information about the subjects covered. The Interdisciplinary Nature of Occupational Safety and HealthOccupational health and safety has its roots in several disciplines, including such diverse fields as engineering, toxicology, epidemiology, medicine, sociology, psychology, and economics. Occupational safety and health is a multidisciplinary endeavor requiring knowledge from diverse sources to deal with the interacting factors of people, technology, the work environment, and the organization of work activities. Any successful approach for the prevention of injuries and health disorders must recognize the need to deal with these diverse factors using the best available tools from various disciplines and to organize a systematic and balanced effort. Large companies have many resources that can be called on, but small companies do 35

The objective of this study was to derive empirical knowledge of the visual search strategies of computer users who suffer from age-related macular degeneration (AMD). This was accomplished by recording eye movement during the use of feature-enhanced software. The results from this study show that there are differences between users who have AMD and users who are fully sighted (FS). Detailed analyses confirmed the hypotheses that there would be performance differences between the AMD and FS participants, and that specific features of the interface, namely icon size, background color, and the number of icons on a display, would significantly affect the search strategies of users.