ABSTRACT
It is not surprising that the underlying causes of musculoskeletal disorders (MSDs) are complex, multi-
factorial, and difficult to determine. Despite decades of research, the numbers of individuals developing
MSDs are still quite high. Yelin et al. (1999) reported that 90% of disabled older workers had MSDs.
Further, it was estimated that 18.4% of the U.S. population (nearly 60 million individuals) will suffer
from one or more chronic MSDs by the year 2020 (Lawrence et al., 1998). Treatment of these disorders
is in the tens of billions of dollars (Praemer et al., 1999). These injury statistics suggest that the current
methods for identifying and reducing or eliminating MSDs in today’s industries have not been
completely effective.
