Lower Back Joint Torque Relief Frame Mechanism for Lifting a Heavy Object by Hand

In this paper, a novel lower back joint torque relief frame mechanism was proposed. Then the function of proposed mechanism was evaluated by calculated value of lower back joint torque. There are many tasks that are required to unnatural postures and difficult hard work that mechanization is difficult in a wide range of fields such as care, logistics and agriculture. In our method, lifting a heavy object load by the subject arm is reduced by using a proposed mechanism which holds the subject's lower back joint at the chest, the lower back and the thigh. In order to consider the function of the mechanism, an experiment of one subject lift 10.0 kg object was conducted. At this time, the forces which occurred at the chest, the lower back and the thigh were measured by load cells. From the experiment, the proposed mechanism was able to reduce the values of lower back joint torque. Further, the values were at least 2 Nm. The proposed mechanism has a function which reduces the load of the lower back by lower back joint torque relief.