The purpose of this study is biomechanically to analyze whole-body motions such as manual handling using a musculoskeletal model. The subjects handled and lifted a load with various trajectories, and the motion and external forces during tasks were measured by a motion capture system with force plates and force transducers. A musculoskeletal model consisting of 15 rigid links and 56 muscle models was employed/constructed to estimate internal loads, such as joint moments and muscular tensions. Using the collected data and the musculoskeletal model, manual handling tasks were quantitatively evaluated from a biomechanical point of view.