Hewett et al. (1996) describes the discipline of Ergonomics as follows: "As with human factors, the concerns of Ergonomics tended to be at the sensory-motor level, but with an additional physiological flavor and an emphasis on stress. Human interaction with computers was also a natural topic for ergonomics, but again, a cognitive extension to the field was necessary resulting in the current "cognitive ergonomics" and "cognitive engineering." Because of their roots, ergonomic studies of computers emphasize the relationship to the work setting and the effects of stress factors, such as the routinization of work, sitting posture, or the vision design of CRT displays."
References (bibliography)
Hewett, Thomas T., Baecker, Ronald M., Card, Stuart K., Carey, Tom, Gasen, Jean G., Mantei, Marilyn, Perlman, Gary, Strong, Gary W. and Verplank, William (1997). ACM SIGCHI Curricula for Human-Computer Interaction. Retrieved 7 August 2003 from ACM SIGHCI: http://sigchi.org/cdg/index.html