Advances in robot development involves autonomous work in the real world, where robots may lift or carry heavy objects. Motion control of autonomous robots is an important issue, in which configurations and motion differ depending on the robot and the object. Isaka et al. analyzed that lifting configuration is important in realizing efficient lifting minimizing the burden on the lower back, but their analysis was limited to weight lifting of a fixed object. Biped robot control requires analyzing different lifting in diverse situations. Thus, motion analysis is important in clarifying control strategy. We analyzed dynamics of human lifting of barbells in different situations, and found that lifting can be divided into four motions.
