Date of Award

Spring 1995

Document Type


Degree Name

Doctor of Philosophy in Applied Mathematics - (Ph.D.)


Mechanical and Industrial Engineering

First Advisor

Howard Gage

Second Advisor

Thomas Spencer

Third Advisor

David S. Kristol


Cumulative trauma of the upper body is associated with a variety of individual and job factors. An effort to optimize the human-hardware interface to minimize cumulative trauma is favored. Workers in a set of jobs had complained about hand/wrist and shoulder discomfort. One job was selected for testing alternate machine controls and worksite layout. Electromyography was used to test muscle activity, and photogoniometry was used to measure posture.

For the group of ten worker-subjects, statistically significant decreases in hand/wrist and shoulder muscle activity were found. A marginal, but significant increase in neck muscle activity was also found. When one subject was excluded, improvements were unchanged and the increase in neck muscle activity was not significant for three of four types of analysis of variance. While statistical improvement was identified, the question of clinical significance cannot be answered at this time.