Biomechanical simulation of manual lifting using spacetime optimization.

Previous optimization techniques for the prediction of lifting motion patterns often require a change in either the number of variables or the order of the mathematical functions used to express the angular displacement of selected joints in response to change in variant conditions. The resolution of predicted results can also be seriously constrained by the number of variables used. These restrictions may often limit the applicability of these methodologies. In this paper, we proposed a new methodology for generating the optimum motion patterns for para-sagittal lifting tasks. A detailed description of this methodology is introduced. An example of an analysis using this methodology is presented. The computer program generated lifting motion patterns with a reduction of the overall objective function values. The actual versus predicted lifting motion patterns are compared. Using this method, constraints can be added anywhere within the lifting cycle without the need of rewriting the whole program. These features provide for a more flexible and efficient prediction of the lifting motion.