A Calculation of Dynamic Back Compressive Force: A Pilot Study of Identify Load Displacement Velocity Constants

Improvement of current biomechanical models through implementation of a dynamic factor may provide greater accuracy in acquiring more realistic calculations of back compressive force (BCF) in the spine during lifting. Most widely used biomechanical models for job evaluations in industry are simplified and considered " static " models. These models neglect additional forces generated by acceleration of the body segment centers of mass and load, and therefore under predict peak BCF in the spine. Few researchers have addressed these issues; however those that have indicate a 19-200% increase in peak force, over static BCF calculations. This was a pilot study designed to answer two main questions: 1. How does a static BCF calculation increase considering dynamic motion during slow, medium and fast lifting speeds? 2. Can a LDVC be used to modify a static BCF model and calculate a more representative measure of BCF? Results of this study indicate that peak BCF increased as much as 42% for fast vs. slow lifting, and 32% for fast vs. moderate lifting. Incorporating the LDVC into static BCF calculations will more accurately represent true BCF and therefore improve risk estimation of back injuries from lifting tasks.