Analysis and modeling of back injuries aboard U.S. Navy Vessels

Abstract

Work aboard U.S. Navy vessels is often physically demanding, and personnel working in such environments are frequently at risk of back injury. Between 1994 and 1998, the U.S. Navy reported 968 back injury mishaps aboard ships and submarines which resulted in 3,283 lost workdays, 5,753 days of restricted activity, and 611 days of hospitalization costing $4,758,000 in constant year 1998 dollars. The high frequency and enormous costs associated with back injury mishaps create an opportunity to increase personnel readiness and reduce operational costs through prevention. This study entailed an analysis of Afloat Special Case Mishaps for back injuries from 1 October 1993 to 30 September 1998 to develop a means of evaluating intervention effectiveness. Using descriptive statistics and categorical data analysis to measure injury arrival rates and identify back injury risk factors, a stochastic model of the back injury arrival process is developed as the foundation for event simulation. The simulation model of back injuries is then used to measure the expected outcome of interventions to reduce the number of injuries, days lost, days of restricted activity, days of hospitalization and total cost.