Development of a safety index for manual lifting tasks

The concept of a safety index (SI) for assigning a worker to a particular manual lifting task is developed, and a simple formula for its calculation is presented. The proposed index is based upon the combined measure of acceptability of the biomechanical and physiological stress responses of the worker to a lifting task. Individual capacity norms, as opposed to the norms usually given based on population percentiles, are also defined. Numerical examples are given to illustrate the SI approach.