Toward an understanding of dynamic variables in ergonomics

Although researchers have shown that dynamic activity may greatly increase the predicted loading experienced by a joint, most ergonomic assessments in the workplace have focused on the postures of the workers and the loads imposed on a joint due to these postures, ignoring the influence of dynamic motion on joint loading. Current technologic advancements now allow the performance of dynamic ergonomic assessments that were impossible a few years ago. This chapter reviews the recent efforts to understand how occupational settings influence the joint motions and subsequent risk of suffering an injury or illness, including the effect of trunk motion on the reaction of joint-supporting structures and the subsequent loading of the spine and wrist. The back appears to be sensitive to the velocity component of motion, and the wrist to acceleration.