Carpal tunnel syndrome due to keyboarding and mouse tasks: a review

So far, many different studies have examined possible implications of typing related posture and activity on carpal tunnel syndrome (CTS) incidence. Although they tend to present the findings as very apparent ones, assessing the complex relationships between the different causal factors implicated in keyboarding and in the usage of pointing devices, on the one hand, and work related upper extremity disorders (WRUED), especially CTS, on the other hand, is problematic. The aim of this review paper is to outline relevant information about CTS risk factors present in data entry task and their implications, with a special emphasis on different extreme postures determined by conventional and alternate keyboards, pointing devices and their role in the development of CTS. Secondly, a comparison of several keyboards with respect to design of keyswitch to reduce force and its effect on carpal tunnel pressure (CTP) is provided. This review critically considers the factors implicated in the occurrence of CTS due to computer work, analysing the determining factors from a well-considered perspective instead of considering them separate entities. Many ''ergonomic" keyboards change the musculoskeletal region exposed to risk, instead of eliminating hazardous postures. The ergonomic assessment of new devices should precede their introduction and not follow it. Future research should be directed to establish a comprehensive understanding of what combinations of trigger factors should be eliminated or modified, to assess the impact of workstation redesign and to uncover the interrelationships between different factors that contribute to the development of CTS. Relevance to industry Because of the trend in the occurrence of the Repetitive Strain Injuries (RSI), especially CTS with keyboard and mouse use, the assessment of all the causal factors, as well as the interrelationship between them in the development process of CTS in data entry tasks will lead to a decrease in medical and non-medical costs. Information could be used for job redesign in order to increase ergonomic qualities and productivity. (C) 2003 Elsevier Science B.V. All rights reserved.