ABSTRACT
In the recent past, cumulative trauma disorders (CTDs) have been the fastest growing occupational health
problem. Compared to 1981 when only 24% of all occupational musculoskeletal disorders were CTD, in
1992 almost 66% of all work related illnesses reported in the United States were attributed to this category
(Bureau of Labor Statistics, 1994). Since changes have occurred in many jobs during recent years (charac-
terized by less force demands and increased mental load, higher social stress leading to a sustained
increase in muscle load) (Viikari-Juntura and Riihimaki, 1999), this trend is expected to continue.
This trend is even more visible in office work. Hence, ergonomic intervention becomes very important.
