The proposed research effort will focus on the development of engineering controls to reduce the likelihood of injury due to slip trip and fall injuries in the construction and transportation industries. Falls were the most costly insurance claims for the construction industry, and were second only to motor vehicle accidents in the transportation industry. The focus of this effort is the development of a general understanding of the mechanisms of falls and slips on an unimproved surface. If this small grant indicates that a potential exists for controlling these injuries through engineering controls, future work would be directed toward testing of those controls. Information on the mechanisms of falls in this environment is currently limited. A number of potential engineering control approaches however do exist. The controls range from specific work boot sole designs for particular types of soils to modification of soil modulus and strength through the addition of fibers. In both cases the costs would be modest for a number of applications and could have significant financial impact, particularly when viewed from the perspective of a human capital approach. Tests will be performed and an existing model extended to make it possible to predict the impact of some of the engineering controls on the mechanics of walking. In addition a small scale study will be performed to determine if the mechanics of walking are impacted by surface conditions.