Effects of Pacing on Spinal Loads When Using Material Handling Systems

Material Handling Systems (MHSs) are a potentially simple approach toward alleviating physical loads and injuries associated with manual material handling. There are, however, relatively few empirical guidelines or evaluations of MHSs that support effective design and implementation. A particular problem with MHSs is the substantial dynamic loading that can result when tasks are attempted at rates comparable to those in manual operations. To investigate such speed effects, a laboratory study was performed in which several biomechanical indices were obtained while volunteer subjects performed a variety of elemental MHS transfer operations. Results indicated that moderate increases in execution speed, on the order of 20%, will be associated with ∼10% increase in spine forces, and also increases in torso muscle antagonism.