- Musculoskeletal-related occupational illnesses and injuries comprise a majority of military medical encounters resulting in decreased combat readiness and degraded human performance. An artillery company performing a live fire exercise was observed for two days along with the collection of perceived exertion, fatigue and pain data. Twenty-five U.S. Marines were involved in the study. Sixteen (64 %) reported becoming injured after returning from combat during a “Call for Fire” exercise and four (16 %) were on limited duty at the time of the study. Their perceptions of exertion, fatigue, and pain increased over the course of both days. In addition, human error also increased over the course of the day and moral decreased as well. The study uncovered that the exposure profile during the support of the “Call for Fire” exercise is leading to degradations in physical performance and increased exposure to physical work place risk factors resulting in various soft tissue injuries.