The finding of a higher prevalence

The finding of a higher prevalence of symptoms in the wrist supports the reports of positions of ulnar deviation and wrist extension among mouse users (Karlqvist et al., 1994; Fernstrom and Ericson, 1997; Cook and Kothiyal, 1998; Burgess- Limerick et al., 1999b). Ulnar deviation and wrist extension have been documented to be risk factors in musculoskeletal disorders of the upper extremity (Hunting et al., 1981; Hagberg et al., 1995). Fogelman and Brogmus (1995) reported an increased prevalence of wrist disorders amongst mouse users. Although the time with the hand on the mouse was not related to wrist/hand symptoms, working with the shoulders in elevation was found to be significant. This reported posture may indicate presence of a high work surface, a reported risk factor for wrist/hand symptoms in some studies (Hunting et al., 1981; Sauter et al., 1991). The increase in shoulder elevation may also be related to postures adopted during mouse use, an area which has not previously been well described in the literature. Other studies report finding low keyboard placement rather than high as a risk factor