Model development for the estimation of back compressive force and subsequent low back disorder risk

Low back disorders (LBD) continue to be a costly problem in the workplace. Employees and employers both suffer loses from the effects of low back disorders and debilitating injuries associated with manual material handling (MMH), specifically lifting and lowering. Current knowledge and understanding of the risk factors related to low back injuries are limited. The purpose of this work was to aid in the development of a biomechanical model to estimate peak back compressive force (BCF) in the spine at the L5/S1 intervertebral disk. This was accomplished in three parts. Part one described the effectiveness of using a statistically based biomechanical model to predict posture during lifting and lowering. Part two contained a refined model developed to estimate BCF from a hand-calculated back compressive force model (HCBCF). Part three incorporated a modification constant into a HCBCF model to estimate BCF to include inertial loads caused by mass accelerations during lifting/lowering. The result of this work was a model capable of estimating peak BCF during lifting/lowering tasks to aid in the identification of j ob hazards and subsequent risk of developing low back injuries.