Ergonomics is the scientific study of the interaction between people and machines. The discipline aims to design equipment and environments that best fit users’ physical and psychological needs, thus improving the efficiency, productivity and safety of a person using a device. A multi-disciplinary field, ergonomics encompasses aspects of psychology, physiology, industrial design and mechanical engineering. The field is divided into three main areas. Physical ergonomics addresses the relationship between human anatomy and physical activity, for instance designing tools that minimize or eliminate muscle strain. This area also looks at how the physical environment affects performance and health. Cognitive ergonomics studies the mental processes involved in humans’ interactions with systems, such as computer interfaces. In designing an airplane cockpit, for example, it is of vital importance that control panels take human factors into account. Organisational ergonomics focuses on optimising socio-technical systems, such as team structure and work processes. Increasingly, progressive organisations are looking for ways to improve workplace ergonomics. The benefit of this strategy is not only increased productivity but also reduced sick leave. In the United States, compensation to workers with repetitive strain injuries costs $20 billion annually.