Based on the spacetime optimization method, a computer simulation system using a five-link dynamic musculoskeletal human model was built to generate the optimum manual lifting motion patterns. Five subjects’ lifting motion data was collected by a motion tracking system. Using the anthropometric data from the subjects, the spacetime algorithm generated the optimal lifting patterns for each subject according to objective function and constraints. The simulation results indicated that:
• this computer system can create a suitable lifting motion patterns for each individual,
• various objective functions and constraints will create different lifting motion patterns, and
• prescribed lifting patterns can successfully reduce the overall value of lower back compressive force, which is associated with injury incidence rates in manual tasks, during the lifting period when compared to the value that was calculated from the original measured lifting motion patterns.
This system may provide a lifting techniques training tool or be used by ergonomists to help design or evaluate the workstation to prevent injury in manufacturing environments which require workers to perform lifting tasks.